Posts on falkp.no/blog

Migrated to Hugo

Sat, 19 Sep 2026 00:00:00 +0200

Blog migrated to Hugo. Let me know if you find missing or bad content. Earlier generator, tinkerer, was deprecated a long time ago.

Bad battery choice

Sat, 21 May 2022 00:00:00 +0000

Shelly sells a smarthome sensor called Door/Window2. It works well, use wifi, is very configurable and can be used locally, without cloud. Unfortunately they’ve chosen a weird, expensive battery option, CR123A. It can cost around 70 NOK (~10 USD), and does not exist as a rechargable option. And you need two of them! So what do you do if you only have one left?

Use a single, abundant 18650 instead!

It fits almost perfectly, has higher capacity and can be found in any discarded electronics. They are always rechargable, and most have an included protection circuit.

The CR123A is 3 V, so two gives 6 V. A standard lithium-ion is 3.7 V (2.7-4.2 actually), but this still works. The ESP8266, which the sensor is based on, can in theory run on 1.7-3.6V.

Unfortunately the cover is just a bit too narrow for them. May need to design a new one suitable for 3D printing.

Edit: Never mind, someone beat me to it! Shelly DW2 18650 Case

Solar panel to DC heater

Mon, 16 May 2022 00:00:00 +0000

In Norway electricity is the most popular form of heating for households at 96% (source). Pure 230V AC is a very high-level energy, and we don’t really need that precision for heating.

This is a project to see if easy, not-perfect, locally generated energy can be used to lower the heating bill.

Disclamer: this is mostly for fun. A more economic aproach would be insulation, heat pump, put on a sweater, etc.

# The plan

             ┌──────────────────┐
             │                  │
             │                  │
   ┌─────┐   │  ┌──────────┐    │
   │     │   │  │          │    │
   │ PV  ├───┼──┤ Heater   │    │
   │     │   │  │          │    │
   └─────┘   │  └──────────┘    │
             └──────────────────┘
                  House

A solar panel, with no controller or inverter, and a heater. Dumping heat in a basement that needs heating all year round.

# The problem

Solar panels have an optimal voltage, where they produce most power, and this changes based on light conditions. A proper controller (MPPT) is expensive, so I want to see if I can do without.

# Hardware

Specs of my first setup:

180 Watt panel (the most power I could get in a normal 12 Volt range)
100 Watt heater with fan (I’ve ordered a 180 W model too)
ESP8266 for statistics (with dht22, ads1115, acs712)

# Setup

The panel, wall mounted in a very sub-optimal location (shadows from people, walls).

Panel connections in
Current sensor
Relay to switch off
Connections out to load

The heater with fan. It’s tiny. The heater is a PTC, so I don’t think it will pose a threat if the fan dies. In front of it is a white temperature sensor, to see that we actually produce heat.

A micro controller, with an external ADC. The micro controller generates graphs and control the relay. The resistors by the ADC are a voltage divider, to scale down the ~23 Volts the panel can deliver to a safe 5 Volts the ADC can measure.

Unloaded the panel will be at ~22 V. With this load one can see that the output is only good when the potential keeps between 12-14 V. I have no way of controlling the voltage, except for changing to a smaller load (less effective heater).

Graph of power output. Totally this gave around 600 Wh on a mostly sunny day.

Green line is the temperature sensor next to the heater. Measuring right next to the fan, I’ve seen it at ~60 °C, but this one is placed a bit away. The orange line is a temperature sensor elsewhere in the room. The room seems to rise about 2 °C during a day. The gray field is cloudyness in percent.

# Conclution

So far this seems to generate heat as it should, but it will have to run for a pretty long time to earn back the ~1700 NOK I paid for the panel. I will test with different heaters to see if I find something that works better. A posibility is also to have several heater that can be switched on with relays based on the power available. A kind of very crude MPPT.

# Thermal

The panel seems to have some significant hotspots. Normal? Cheap panel?

The relay is producing heat, but waste heat isn’t a problem in this case. =)

The relay is pulling more current than a GPIO from the ESP is rated for, so it’s voltage regulator is getting very hot. Should probably fix that.

OpenWRT on Altibox VLAN

Tue, 12 Apr 2022 00:00:00 +0000

An ISP in Norway, Altibox, serves up VLANs for VoIP, IPTV and internet. The included router gives no control or options for LAN management. I only use the internet service, so I replaced it with a generic router running OpenWRT. I found no straight forward answer to how to configure it, so here it is.

# The situation

    ,--.
  (      )                 +--------+
 (internet)    -> VLANs -> | router | -> LAN
/__________)               +--------+

AFAIK the VLANs used are:

100 - VoIP / router remote config
101 - IPTV
102 - internet

# How-to

These are the settings you need to change in OpenWRT.

Switch:

change vlan 2 to 102
change wan on vlan 102 to tagged

Save and apply

Interface:

edit wan
change device from eth0.2 to eth0.102
repeat for wan6

Save and apply

BlueDo - Bluetooth proximity automation

Sat, 28 Aug 2021 00:00:00 +0000

Lock your desktop, mute music or run any other command when leaving your PC. There are dozens of apps like this. This one just aims to make it beautiful, modern and easy.

Blueproximity was a program to do this, but it never worked great for me, and has since rottened. This project was inspired, but I trid making it Gnome-ish. That means simple, limited options, but does the job.

The idea is to monitor bluetooth reception from a paired device (i.e. a phone), and perform actions based on signal quality. In an office this works good for locking / unlocking your session when you’re away.

Easy install from pip. See more screenshots and read instructions at gitlab.

Check Commander - Curses interface for Checkmk

Sat, 24 Oct 2020 00:00:00 +0000

A curses interface for checkmk. I named it Checkmk Commander, but Check Commander is easier to say.

I use Checkmk daily. A few common tasks are acknowledging, downtiming and reinventorizing hosts and services. In the web UI this takes lots of clicks and time. So I wrote this client to optimize my workflow.

Example workflow in web UI:

A new service has been detected on host1, thus I have to reinventorize it.
Click on host name.
Click WATO
Click services
Click “fix all missing/vanished”, wait.
Click “1 change”
Click “Activate affected”, wait.

The same in Check Commander:

A new service has been detected on host1, thus I have to reinventorize it.
Navigate up/down to target the host
Hit “r” and enter to confirm. Reinventorize happens in background, and one does not have to wait for it.

There are hotkeys for opening web pages (or run other commands) linked with the selected host. I use “w” to open the host’s wiki page, “b” to open the checkmk web UI in browser and “t” for opening a new terminal with ssh to the host.

Since this is in curses, one can also run it in tmux or on a terminal server. Browser commands can then open in elinks, w3c, or other suitable CLI software.

Easy install from pip. See screenshots and read more at gitlab.

Checkmk Plugins, part 1

Sat, 11 Apr 2020 00:00:00 +0000

Some of my checkmk plugins, Webchecks, Blacklist and SQL Dump. Easy deployments.

# Blacklist

If you have a server which is sending mail, drop this check in place. It will check the host it’s running from against a bunch of blacklists. No configuration needed.

checkmk-blacklist:

# Webchecks

Easy and expansive check of web services. It will:

Follow redirects
Check (configurable) status code
If ssl, check cert and chain. Check remaining time.
Configurable string check.
If URL contains dev, stage or such, complain if the site isn’t robots-blocked. Else, complain if the site is robots-blocked.
Find URLs to check from apache or nginx config.

checkmk-webchecks:

# SQL dumps

This one is of less general use, and is published more as an example for further development. It’s written for an inhouse SQL dumper, somewhat similar to automysqlbackup. It will check for a running database server, and if found check for recent database dumps.

checkmk-stasissqldump:

Argos, GNOME Shell extensions

Wed, 01 Apr 2020 00:00:00 +0000

Argos is a free GNOME version of BitBar. Both lets you run any script to create an icon in the panel (or Mac OS X Menu Bar). You can see lots of plugins here: BitBar plugins.

This screenshot shows the hosts file, opened from the argos extension. The extension is shown as a notebook icon with the number of unknown entries.

It complains on forgotten entries in your /etc/hosts file. See Argos-hosts for more info.

Graphing X Aircontrol from Trox Technik

Wed, 01 Apr 2020 00:00:00 +0000

Modern buildings have advanced HVAC systems, but they keep the data for themselves. Let’s fight that. =)

I got access to an X Aircontrol from Trox Technik, ZoneMaster HVAC system. It has a web server, so I started playing to see what data could be extracted.

I ended up with this script xaircontrol, which can send data to Grafana via Collectd.

We’ve used it to make some sweet floorplans.

Non-invasive graphing of energy usage

Wed, 01 Apr 2020 00:00:00 +0000

“If you can’t measure it, you can’t improve it.”

Reducing energy usage is hard if you can’t see it. Here’s a cheap way to graph home or office energy usage.

By reading data from the energy meter, one can get super accurate, real-time usage data.

I’ve used:

A smart home controller, Home Assistant
A graphing system, Grafana
A micro controller, esp8266, ~$5
An LDR sensor, $1

You need some familiarity with all of the above to set this up.

Here’s my energy meter:

It doesn’t matter which one you have, as long as it has a LED that blinks each X kWh used. I’ve written software for the esp8266 in MicroPython, called esp_energy_meter, that measures the time between each blink. It works great, and I’ve had it running for several locations for years. See the gitlab repo for more info on setup.

When you have this set up, you can combine it with real-time energy prices to get full control of your energy usage. And then it’s time to adjust your usage based on pricing. =)

VEML7700 in ESPHome

Sat, 29 Feb 2020 00:00:00 +0000

I have a VEML7700 digital light level sensor, which is not supported by ESPHome, but can be used as a custom i2c component. This is how:

# espnode.yaml

esphome:
...
includes:
    - veml7700_custom_sensor.h
libraries:
    - "https://github.com/adafruit/Adafruit_VEML7700"

sensor:
- platform: custom
    lambda: |-
    auto veml7700 = new VEML7700CustomSensor();
    App.register_component(veml7700);
    return {veml7700, veml7700->lux_sensor, veml7700->white_sensor, veml7700->als_sensor};
    sensors:
    - name: "VEML7700 Light" # Required dummy sensor
    - name: "VEML770 Lux"
        unit_of_measurement: Lux
        accuracy_decimals: 0
    - name: "VEML770 White"
        unit_of_measurement: raw
        accuracy_decimals: 0
    - name: "VEML770 ALS"
        unit_of_measurement: raw
        accuracy_decimals: 0

# veml7700_custom_sensor.h

#include "esphome.h"
#include "Adafruit_VEML7700.h"

// Requires this lib installed: $ platformio lib --global install "Adafruit BusIO"
// based on https://github.com/adafruit/Adafruit_VEML7700/blob/master/examples/veml7700_test/veml7700_test.ino


class VEML7700CustomSensor : public PollingComponent, public Sensor {
public:
Adafruit_VEML7700 veml = Adafruit_VEML7700();

Sensor *lux_sensor = new Sensor();
Sensor *white_sensor = new Sensor();
Sensor *als_sensor = new Sensor();

VEML7700CustomSensor() : PollingComponent(15000) {}
void setup() override {
    Wire.begin();
    veml.begin();
    veml.setGain(VEML7700_GAIN_1);
    veml.setIntegrationTime(VEML7700_IT_800MS);
    // veml.powerSaveEnable(true);
    // veml.setPowerSaveMode(VEML7700_POWERSAVE_MODE4);
    // veml.setLowThreshold(10000);
    // veml.setHighThreshold(20000);
    // veml.interruptEnable(true);
}

void update() override {
    float lux = veml.readLux();
    float white = veml.readWhite();
    float als = veml.readALS();
    ESP_LOGD("VEML7700", "The value of sensor lux is: %.0f", lux);
    ESP_LOGD("VEML7700", "The value of sensor white is: %.0f", white);
    ESP_LOGD("VEML7700", "The value of sensor ALS is: %.0f", als);
    lux_sensor->publish_state(lux);
    white_sensor->publish_state(white);
    als_sensor->publish_state(als);
}
};

Nordlux lamp. Incompetence or planned obsolescence?

Sat, 01 Feb 2020 00:00:00 +0000

I got this lamp from Nordlux, model 6315. It came with unreplacable LEDs, meaning you have to throw it away when they run out. Apparently the LEDs are rated for 30.000 hours, but will they last that long?

Nordlux at Bauhaus

After a few years of normal use it died. I could hear the relay turning on and off, but there was no light. I followed the power all the way, and there seemed to be no problem with the transformer, relay or wires. I tried checking the voltage drop over a LED, and that gave a slight glow in all the other LEDs. So it seems the LEDs are connected in series! Meaning that if any of the 24 LEDs die, you have to throw away the whole lamp. I’m unsure wether this is incompetence or planned obsolescence. What are the odds of all LEDs lasting a long time?

The broken LED is apparent with a small mark on it.

The lamp works again if the broken LED is shorted. This “repair” is only for testing. I do not suggest using a lamp in this state.

ZFS on laptop with encrypted /home

Sun, 22 Dec 2019 00:00:00 +0000

With Ubuntu 19.10 it’s simple to get a workstation with boot and root on ZFS. But what’s missing from the install is encryption. This is how I did it.

I suggest you first have:

basic zfs knowledge
good linux knowledge
no important data on the target system
more than 4 GB RAM
SSD or better

# How-to

Install Ubuntu as normal, but choose “use ZFS”. It’s marked as experimental, but that’s because how Ubuntu uses it may change in later releases. The code it self is solid.
After install is done, you’re left with a bpool and an rpool. I will only focus on encrypting /home/. I’ll use username john in this example.
Your layout will look something like this:

$ zfs list -r rpool
NAME                                               USED  AVAIL     REFER  MOUNTPOINT
rpool                                              165G   293G       96K  /
rpool/ROOT                                        18,8G   293G       96K  none
rpool/ROOT/ubuntu_oyzpo3                          18,8G   293G     3,92G  /
rpool/ROOT/ubuntu_oyzpo3/usr                      1,06M   293G       96K  /usr
rpool/ROOT/ubuntu_oyzpo3/usr/local                 992K   293G      144K  /usr/local
rpool/ROOT/ubuntu_oyzpo3/var                      13,4G   293G       96K  /var
rpool/ROOT/ubuntu_oyzpo3/var/games                 320K   293G       96K  /var/games
rpool/ROOT/ubuntu_oyzpo3/var/lib                  4,36G   293G     3,72G  /var/lib
rpool/ROOT/ubuntu_oyzpo3/var/lib/AccountServices   320K   293G       96K  /var/lib/AccountServices
rpool/ROOT/ubuntu_oyzpo3/var/lib/NetworkManager   3,67M   293G      208K  /var/lib/NetworkManager
rpool/ROOT/ubuntu_oyzpo3/var/lib/apt              87,0M   293G     74,9M  /var/lib/apt
rpool/ROOT/ubuntu_oyzpo3/var/lib/dpkg             87,4M   293G     41,2M  /var/lib/dpkg
rpool/ROOT/ubuntu_oyzpo3/var/log                   574M   293G      170M  /var/log
rpool/ROOT/ubuntu_oyzpo3/var/mail                 2,25M   293G      104K  /var/mail
rpool/ROOT/ubuntu_oyzpo3/var/snap                 8,46G   293G     8,46G  /var/snap
rpool/ROOT/ubuntu_oyzpo3/var/spool                10,4M   293G     3,51M  /var/spool
rpool/ROOT/ubuntu_oyzpo3/var/www                   320K   293G       96K  /var/www
rpool/USERDATA                                     141G   293G       96K  /
rpool/USERDATA/john_75qybu                         140G   293G      126G  /home/john
rpool/USERDATA/root_75qybu                        1,07G   293G     1,07G  /root

We want to replace rpool/USERDATA/john_75qybu with a new, encrypted file system.

Create another temporary user, smith, and log out of john and in as smith.
Set filesystem name in a variable, so you can copy/paste the rest: $oldfs="rpool/USERDATA/john_75qybu"; $newfs="rpool/USERDATA/john_crypt"
Unmount: sudo zfs umount $oldfs
Reset mountpoint: sudo zfs set mountpoint=none $oldfs
Create a new, encrypted file system for your main user: sudo zfs create -o encryption=on -o keyformat=passphrase $newfs
Set mountpoint: sudo zfs set mountpoint=/home/john $newfs
Mount: sudo zfs mount -a
If you get complaints on missing key, run: sudo zfs load-key -a and then mount again.

If you had any data on the unencrypted home dir, you can mount it anywhere else (zfs set mountpoint=/mnt ...), and copy data.

Last thing you need to do is enable key loading at boot.

Create the file /etc/systemd/system/zfskey-tank@.service as:

[Unit]
Description=Load %I encryption keys
Before=systemd-user-sessions.service
Before=zfs-mount.service
After=zfs-import.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/bin/bash -c 'systemd-ask-password "Encrypted ZFS password for %I" --no-tty  | zfs load-key -a'

[Install]
WantedBy=zfs-mount.service

Note that I’ve changed the suggested example from Arch Wiki which ended in zfs load-key %I to zfs load-key -a. That way all encrypted filesystems will be mounted.

And enable: $ sudo systemctl enable zfskey-tank@john_crypt

Reboot and check that everything works. If you have trouble logging in, you can log in as smith and check what fails. Unlocking, mounting or access rights. It will look the same in a zfs list, but you should see a difference if you run:

$ sudo zfs get encryption rpool/USERDATA/john_crypt
NAME                         PROPERTY    VALUE        SOURCE
rpool/USERDATA/john_crypt  encryption  aes-256-ccm  -

If everything works, you can move along to setting up snapshots or other fancy zfs stuff. =)

# Resources

Arch wiki

Ninjabox

Fri, 23 Nov 2018 00:00:00 +0000

# Overview

Untrickable laser alarm, with an easy-to-knock-out fusebox.

A tribute to (the alarms in) Mark of the Ninja.

# Background

In the game you have to sneak into buildings with high tech alarms. Some of the laser traps can be deactivated by knocking out the fuse box with a dart.

So I made a laser alarm with a fusebox that can be knocked out. This is mainly to keep kids occupied, and motivated to practice throwing.

# Features

Glowing ⚡ with simple animations and color changes (start-up, alarm, sparks)
Laser triggered alarm, which can’t be fooled by using a separate laser or flash light. This is done by pulsing the laser and making sure photo resistor is relatively dark when laser is off.
Motion activated “play dead” (throw somehting on the fuse box, and it will black out for 10 seconds).
Play sounds for alarm, sparks, start-up

# Demo

Knocking out the alarm (~3MB).

Attempting to fool the alarm (~2MB).

Not shown here: speaker and tiltsensor.

See gitlab for build instructions and code.

Car-logger - part 3

Fri, 25 May 2018 00:00:00 +0000

# Overview

A self-hosted, real-time, inexpensive open source car tracker built with Raspberry Pi Zero W, Nextcloud, and optionally Home Assistant.

I’ve had a few earlier tries at car position logging, read those first if you’re interested: Car logger 2.

# Background

Goal: logging and sharing location of my non-connected car, for practicality and fun.

Earlier tries was using a phone, but that had problems. No Android phone will switch back on if it runs out of power without manual intervention.

# Prerequisites

I needed power from the car, but want it to cut off when the ignition is off. My 12 V outlets didn’t. So I used a fuse holder with outlet to accomplish this. To that I attached a 12 to 5 V converter.

Also I chose to go without any battery or UPS, so the Pi has to deal with unclean shutdown every time. For this I run the SD card read-only using rpi-readonly.

# Hardware

I had little experience with Arduino at the time of start, but lots with Pi, so I used a Pi Zero. Mainly for it’s low power consumption.

I first tried Diymall-G-mouse-Glonass GPS dongle, but reception was very bad, so switched to BN-808-USB-GPS.

For uplink I used a cheap 3G USB modem Tolkien-Portable and a data-twin SIM card.

# Backend

I started writing a backend in 2014, BigBrotherGPSweb, but didn’t get very far. Fortunately someone has filled my need. Nextcloud, a self-hosted dropbox alternative, has a plugin called PhoneTrack. It has nice features like public sharing, users, filters, etc. and use Openstreetmap. SSL for transport encryption.

For home automation I use Home Assistant, so I also wanted the data there as well.

Map in Nextcloud/PhoneTrack:

Status in Home Assistant:

# Software

I found no premade solution to use wifi triangulation in python, so I wrote wifindme (available from pip, python 2 and 3). It can use Mozilla, radiocells.org or, with small changes, Google. Use what has best coverage where you need it.

For the actual reporting I wrote LocationReporter. It can use wifi triangulation, GPS or both. It will use wifi while the GPS is warming up, and when GPS fails. The results can be sent to both my backends.

# Build

I’ve not yet created any kind of case. The tracker lives in a card board box in my car door.

# Problems

PhoneTrack could be easier to use on a phone.

# Improvements

The setup should be moved to the trunk, out of sight.
I really should get a case and mount the parts properly.
The Pi Zero has bluetooth, so I could fetch data from OBD and upload it. Unfortunately my cars OBD doesn’t supply very interesting info (no battery voltage, fuel consumption, fuel status).
Should be enough to send data to either Nextcloud or Home Assistant, not both.
A switch for private mode or you-don’t-have-to-post-every-ten-seconds mode could be nice.
Radiocells.org let’s you download the data set for local use. Local wifi lookup is very fast, so this would make wifi triangulation faster, and less data used and leaked.

# Conclusions

I’m happy with the results. It’s been running for months now without problems. And it’s good sharing our position real-time on long drives.

Volumio based radio with NFC

Tue, 19 Dec 2017 00:00:00 +0000

# Overview

Volumio based internet radio, controlled by NFC, built in an old speaker.

# Background

Inspired by the extreemly good looking Spotify Box and QR based systems like Audiosphere, I wanted to make something similar for my kids. I’ve earlier built a few radios based on small, cheap bluetooth speakers like music angel, but wanted something with better sound this time.

# Prototype

QR are fast and cheap, so I made a quick prototype. It turned out they are unreliable when there’s no display to give feedback on how the camera sees them. Both lighting and focus was a problem.

Next up, NFC. I decided on a PN532 NFC reader, simply because I had one around. They’re about $8 / 70 NOK on ebay. It communicates via i2c, and there’s a python library for it. I decided to make it easy for myself and allow for any kind of NFC tag I could get hold of, so the plan was to read and use what ever data or ID the tags contain, and make a list to match IDs and URLs.

# Volumio

Volumio is a general music player for small devices like the Pi. Due to Mopidy it supports playing music from lots of sources. The two I’m interessted in are internet radios and Spotify, but this will work for anything Mopidy can play.

Volumio also has plugins for other stuff, like mono output, being a Spotify Connect speaker and button controls connected via GPIO like I will use here.

# Setup

As mentioned in the readme, there are a few steps to install NFC support. You have to enable SSH first. Then install packages, check that the i2c connection to the reader is working, enable services.

Reading a tag looks like this:

$ ./readnfc.py
Reading tag list readnfc.list
6 tags in store. Ready to read.
Card data: bytearray(b'K\x01\x01\x00D\x00\x07\x04!T\xcao?\x81') / 4b010100440007042154ca6f3f81
Stoping any music currently playing
Play audio feedback.
webradio http://nrk-mms-live.telenorcdn.net:80/nrk_radio_alltid_nyheter_aac_h
Play selected source webradio http://nrk-mms-live.telenorcdn.net:80/nrk_radio_alltid_nyheter_aac_h

Then you add that tag to your list, readnfc.list, in the same directory. There are lots of examples for radios and spotify playlists in it already. Restart the service and you should be done.

See demo video (~4MB).

# Hardware

For sound I connected a cheap USB soundcard (first hit on ebay), via a ground loop filter to a Class D amplifier, to the terminals of the speaker.

A 1k potmeter for volume, and two push-buttons for play/pause and next.

# Tags

Any tags works, but they need to look attractive, so I created some business card sized pictures to hold them.

So Hell has frozen over...

Wed, 09 Nov 2016 00:00:00 +0000

So here we are, Hell really has frozen over…

$ finger hell@graph.no
           -= Meteogram for norway/nord-trøndelag/stjørdal/hell
 'C                                                                   Rain (mm)
  0
 -1
 -2      ^^^^^^
 -3   ^^^      ^^^
 -4=--            ^^^^^^
 -5                     ^^^^^^^^^^^^^^^                     ^^^^^^^^^
 -6                                    ------------=--=--^^^
 -7
 -8
 -9
    11 12 13 14 15 16 17 18 19 20 21 22 23 00 01 02 03 04 05 06 07 08 Hour

     E  E  E  E  E  E SE  E  E  E  E  E  E  E  E  E  E SE SE SE SE SE Wind dir.
     2  2  3  4  3  2  2  2  3  3  3  4  4  3  3  3  3  3  3  3  4  3 Wind(mps)

 Legend left axis:   - Sunny   ^ Scattered   = Clouded   =V= Thunder   # Fog
 Legend right axis:  | Rain    ! Sleet       * Snow

RadiOS part 2

Wed, 17 Aug 2016 00:00:00 +0000

# Overview

See RadiOS part 1.

So I started making a prototype to figure out if I could “sense” both selections with GPIO pins, while the designer started modeling and rendering suggestions for the physical design. The solution chosen was to first set all volume control pins to high, and check which channel control points registered as on, then reverse (control points high, check volumes).

# Sound

For sound we tore down a Music Angel portable speaker. It gave us two speakers, an amplifier running on 5V and a battery which we threw away. The built in soundcard gave horrible sound under certain conditions, so a cheap USB soundcard was used instead.

# Case

We wanted to try both a 3D-printed version and a CNC’ed one. A print at Shapeways would cost us ~$200, plus shiping and tax. We got one printed localy for ~$80. It’s has yet to be used. A local CNC person wanted ~$270. The case we’ve used in the final build is hand made of wood.

## Plastic case

## Renderings of other variations

# Prototype

# Build 1

We chose to paint the front in black board paint, to allow easy change of channel labels and a personal touch.

Other builds may have a white board front, or be something very different.

# Conclution so far

It’s an interessting UI, and people want to touch it. However programming the channels and first time setup is hard. Also the Pi or musicbox is very slow to start streaming. This kind of breaks the fun of it.

To be continued…

Using finger service the wrong way

Tue, 31 May 2016 00:00:00 +0000

# Overview

If you’re doing this, you’re doing it wrong…:

2016-05-31 10:19:45.493314 Client 92.x.x.192 hamburg, germany/hamburg/hamburg
2016-05-31 10:19:48.443380 Client 74.x.x.189 greensboro, united_states/north_carolina/greensboro
2016-05-31 10:19:56.733260 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.745653 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.759656 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.819283 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:20:16.287744 Client 5.x.x.13 kaiserslautern, germany/rhineland-palatinate/kaiserslautern
2016-05-31 10:20:35.182942 Client 85.x.x.140 katowice, poland/silesia/katowice
2016-05-31 10:20:47.029550 Client 193.x.x.226 oslo, norway/oslo/oslo/oslo

Lots of people use the finger service @graph.no in an automated way. That’s quite alright, it’s what it’s there for. As an example:

But if you’re asking for the same data five times a second (until you get blocked by my firewall for a minute), you have to check your code. The data is at best changing every ~30 minutes.

A likely scenario is putting it in screen/tmux status line. If you do that, you need to change how often your terminal multiplexer is updating the status line. A better way is to have a cron script fetching the data, and storing it in i.e. /tmp/weather every 30-60 minutes, and then have your status line read from that.

Another scenario could be people running it in watch, which by default updates every two seconds. Also wrong. Please use -n 600 more.

If you fetch the data, and grep out what you need, then fetch the data once, and grep all you like. Don’t fetch for each grep. An example of this can be seen in the client graph.sh, which fetches the data, sed a lot and present it using unicode weather symbols and colors.

Feel free to contact me if you need scripts/examples or have questions.

Also, don’t feel ashamed, beaverton, you’re not alone in hammering me. I just don’t have any way to contact users. I still love you all. =)

Weather via finger, an update

Tue, 31 May 2016 00:00:00 +0000

# Overview

I meant to write this post in February, but never had the time.

Something exploded at Tuesday 2016-02-16.

I created the finger weather service in 2012, and announced it at Reddit. It got some mentions in Norwegian blogs, and i gathered a few regular users. See old stats in previous post.

I’m no fan of social media, and try to stay away. But apparently someone recently noticed the service and tweeted about it. Then blogs. Since I have regularly received “thank you” mails due to one of the random messages at the bottom (Mail a “thank you” to finger@falkp.no if you like the service.).

It not only overwhelmed me, but the service was having trouble keeping up. The code was my first Python project of some size, is not 3.0, and has not been revisited since. It contains lots of unrelated cruft (news, time, date, coffee) which was the start of a terminal screensaver and is certainly not optimized for lots of clients.

After a few freezes, one which caused a night of downtime, I enabled rate limiting (ufw limit), which blocks > 4 subsequent requests from one IP within 30 seconds. The data is cached for 20 minutes anyway (a requirement from the data source), so there’s no use in hammering.

Lot’s of tweets thanked the Meteorological Institute for this: “Norwegian Meteorological Institute provides CLI weather reports.”. While I’m thankful to them for their open data, they do not have any further involvement in this service.

# Common questions I’ve received

## Fahrenheit and u.s. zip codes

Sorry, won’t happen. Not because I don’t want to, but because I don’t have time. I will accept pull requests on github. Zip codes may be hard.

## Can’t find my city

Search for it on http://yr.no. If it’s not there, you won’t find it.
Remove any spaces, attempt to cut off part of the name. Searching is done via MySQLs LIKE operator. I.e. this support request:

I would like to query the weather in Frankfurt am Main, data from here:
http://www.yr.no/stad/Tyskland/Hessen/Frankfurt_am_Main/varsel.xml

All of these Queries give me the weather for Frankfurt/Oder

finger frankfurt@graph.no
finger frankfurtmain@graph.no
finger frankfurt_am_main@graph.no
finger 2925533@graph.no
finger "frankfurt am main"@graph.no
finger "frankfurt main"@graph.no
finger frankfurt_main@graph.no

The solution here was to use frankfurtam. The full name will also work, frankfurtammain.

Some cities will simply not be reachable due to the poor look-up method in use.

If I ever get time, I’d like to rewrite how one locates cities, but I’m guessing it won’t happen.

## Data doesn’t match yr.no / why isn’t my weather hourly

Yr.no supplies data for most of the world, but international treaties keep them from supplying hourly for any place outside their own model (meaning outside of scandinavia). So in scandinavia you’ll see something like this:

$ finger oslo@graph.no|grep Hour
22 23 00 01 02 03 04_05_06_07_08_09_10_11_12_13_14_15_16_17_18_19 Hour

while in other places it will look like this:

finger wellington@graph.no|grep Hour
_09_12_15 18 21 00 03 06_09_12_15 18 21 00 03 06 Hour

I’ve asked them about it, and their hoping for a change to this policy for the countries which are members of ECMWF.

Your own Ruter.no realtime monitor

Mon, 23 May 2016 00:00:00 +0000

# Overview

By request, a quick how-to on setting up your own realtime monitor for ruter.no, Oslos public transit.

# As simple as possible

Get an old laptop
Set it to start a web browser at boot
Make the browser start to i.e. http://mon.ruter.no/monitor/3010314/Adamstuen/2190090

Done!

# Background

Ruter has an API, so you can go crazy and implement your own client easily, like I’ve done with rutercli. But there’s a much simpler solution. They’ve got a website in the same style as their public monitors, mon.ruter.no. You can start with the link above, and find the numbers and names you need from a normal ruter.no search. You’ll also find NSB stuff there. See ruter.no/reiseplanlegger/sanntid/egen-sanntidsskjerm for more info.

# In a white wooden frame

Here’s a basic example in a photo frame:

This one is run by a Raspberry Pi model B, but any model will do. The screen is from Chalk-elec, but any display will do. The frame is a normal photo frame. Then there’s some glue and plastics on the back to hold it all together.

To align two different transits use something like this HTML:

<!DOCTYPE html>
<html>
<head>
<TITLE>Info Screen</TITLE>
<meta http-equiv="refresh" content="6000">
<meta charset="utf-8">
</HEAD>
<body style="background-color:#2a2a2a" scroll="no">

  <iframe src="http://mon.ruter.no/monitor/2190090/Østerås [T-bane] (Bærum)?rows=4 " align="left" width=100% height=550 scrolling="no"  frameborder="0">
  </iframe>

  <iframe src="http://mon.ruter.no/monitor/2190090/Østerås [T-bane] (Bærum)?rows=4 " align="left" width=100% height=550 scrolling="no"  frameborder="0">
  </iframe>

</body>
</HTML>

And to have it start automatically at boot, edit /etc/xdg/lxsession/LXDE/autostart to look like this:

@xset s off
@xset -dpms
@xset s noblank
@unclutter

My crontab:

@daily /sbin/reboot
@reboot sleep 10; /root/browser.sh

And /root/browser.sh contains:

#!/bin/bash

killall midori
midori \
  --app=rutyr.html \
  --display=:0 \
  --execute Fullscreen

Android with as little closed source as possible - part 2

Thu, 26 Feb 2015 00:00:00 +0000

# Overview

Read part one of Android with as little closed source as possible, Life without US cloud services and Androids privacy invasiveness if you’re wondering why I’m doing this.

This is an update on how to live with a free and open (Android based) phone.

Some time during 2014 I went all-in, and removed Google Play. My previous article (Android with as little closed source as possible) left a list of closed source apps I was still dependent on:

Google Maps
Yatse
Youtube
TinyCam monitor free

When dropping Google Play I had to drop Maps and Youtube. They can’t work without. Maps is replaced with OsmAnd, which even can work totally off-line (no data usage, lower battery usage). Youtube can be used via a web browser.

I still have a folder of proprietary apps on my phone, installed via a APK downloader. There’s even an app to let you know when there are updates: ApkTrack. These apps are due to services hard to avoid (Spotify/Wimp for music streaming, Ruter for public transportation, NRK for public broadcast TV, Tesla/Airtame/SeekThermal for special hardware). These apps doesn’t bother me, and the OS with privacy guard has them locked down.

# Firmware

There is still no phone with open firmware in sight. Even FirefoxOS comes with binary blobs. But getting rid of the three big ones, Apple, Google and Microsoft is a good thing, no matter what you’re running.

µg - A plugin-based replacement for gapps (updated)

Sat, 10 Jan 2015 00:00:00 +0000

This is a follow-up of Nogapps - A replacement for gapps.

The NOGAPPS project has been renamed to µg, and the part that interessts me the most, off-line, libre, coarse localization is called µg Unified [Nlp (Network Location Provider)].

The forum is sparse on usage information, so this aims to be a how-to with screenshots.

# Prerequisites

A rooted phone
No Google services installed
Android [4.4 (KitKat)] - [5.0 (Lollipop)]. If you’ve got and older version, see the projects github.

# Installation

Install µg UnifiedNlp. Installing from f-droid is the easiest way.
Now you need providers. Search for nlp in f-droid, and install i.e. GSMLocationNlpBackend. This will give access to two databases of GSM cell towers and their locations.

# Configuration

Find the “µg UnifiedNlp” app and open it, go to “Configure location backends”.

Hit the gear to configure GSM Location Backend.

Mozilla Location Services can be activated right away.
To activate OpenCellId you need an API key. Head over to OpenCellId.org and register.
Make sure you’re on a decent network, preferably WiFi, and hit “Generate Database”. It will download a few hundred MB, depending on your location. Note that one seems limited to one database dump from OpenCellId per day. Subsequent attempts will fail.
You also have to make sure your android location settings are set to “Powersave” (WiFi and GSM) or “High precision” (GPS + WiFi and GSM).

# Backend alternatives

Currently a search for [Nlp (Network Location Provider)] in f-droid gives,

AppleWifiNlpBackend - using Apples WiFi database
GSMLocationNlpBackend - using cellid from OpenCellId and Mozilla Location Services.
LocalGsmNlpBackend - Collecting and using cellids seen by phone. Nothing is uploaded or downloaded.
LocalWifiNlpBackend - Collecting and using wifi seen by phone. Nothing is uploaded or downloaded.
NominatimNlpBackend - “Backend that uses MapQuest’s Nominatim service (based on OpenStreeMap) for geocoding.”. Not sure what this is for.

There seems to be more Network Location Providers on the way, like OpenWLANMap.

# Testing

Now does this work?

Using LocalWifiNlpBackend I can find my location without GPS, fast. But this is a very selfish method (not sharing data), and it only works where your phone has been and had GPS signal before.

I’ve had less success with GSMLocationNlpBackend, even though I know my neighborhood is mapped. Will update this if I experience differently.

OpenWLANMap is probably a better bet for proper localization, so hold on for those to arrive!

Edit: After the update of µg UnifiedNlp (Version 1.2.0 - Added on 2015-01-19), localization works great for me! (And by that I mean the test that failed in the last paragraph).

graph.no - Weather forecast via finger

Sat, 13 Dec 2014 00:00:00 +0000

# The idea

Yr.no has a brilliant hour by hour view. A simple picture where you get all info you need for planning your next 48 hours.

They also give out all their weather data for free! Having a special fascination for the command line, I wondered if I could represent the same information in a basic, ASCII, 80x22 terminal.

# Development

Earlier I’d made my first telnet service for keeping an eye on the status of the office coffee pot (coffee.graph.no / telnet graph.no). After that, I pondered for a while on how to allow for choosing location via such a limited protocol. I did not want to make a service that had to be used by hand, like wunderground, which I discovered later, but one that could be used in an automated sense.

I considered running one instance at each port for a subset of the Norwegian postal codes, like 1000, 2000, 3000, etc. Or even for each hundred. I was stopped in pursuing this by two limitations in xinitd: no support for responding to several ports with one config file, and trouble of passing on which port was used to the daemon.

I also tried to allow for passing an input so that one could run echo “oslo” | nc graph.no telnet. Can’t remember why that didn’t work.

Then I discovered the finger protocol. Or rather how it actually worked. It’s simply telnet with one input, the user name. Perfect.

The solution then became a python daemon, listening at the standard finger port, making a call to YR’s free API and caching the results. I found a python lib for using the API, so I could get right on to presenting the data.

The first working code gave:

After a few long nights it became more or less how it is today:

# Press

I announced it at tillegg.yr.no (first runner up for top rated), and at reddit.com/r/linux.

After that the part owner of YR, NRK, which has a blog discussing new media, the tech behind what they do, etc. called NRK Beta, wrote an article about it: Old Skool-værvarsling.

It’s also been used in a hackathon for littleprinter, see twitpic and flickr, and in various screenshot threads in forums.

# My use

I mainly made it for personal use. I have it at home on a monitor above the door and on a monitor at work. There are also options for small, one-liner outputs, which I’ve used in tmux/screen status bars.

# Improving on tech from the seventies

I can’t use unicode, colors, a larger display, as that would make it incompatible with the original goal of the project. But I’m fond of icons, so I made a client. Yes, a client for a finger weather service. It consists of some messy bash code to fetch, present and refresh the forecast using unicode and colors. You can find it in the git repo of the project, called graph.sh.

# Stats

I do get that there isn’t a big market for this. Especially when it’s so hard to use on a phone (with for example Unix Finger Client), and there are such beautiful alternatives as i.e. forecast.io. Oh, yes, not everyone uses terminals anymore either.

Still I do seem to have gathered a few loyal followers. I even had to block a user once, for hammering the service at about every second.

Here’s an excerpt from my logs the day before I wrote this:

Date: 2014-12-12
Total hits today: 377
Unique IPs today: 11
Top 10 users with hitcount:
 230 85.89.x.x
 36 77.179.x.x
 25 176.68.x.x
 24 77.179.x.x
 21 138.246.x.x
 16 176.11.x.x
 12 217.186.x.x
  4 93.93.x.x
  4 176.11.x.x
  3 46.212.x.x

Top 10 locations:
 230 katowice,
  72 dresden,
  24 oslo,
  21 munich,
  14 karlskrona,
   4 4730,
   2 hurdal,
   2 help,
   1 trondheim,
   1 time,

# Give it a try

Now it’s time for you to try.

## Linux

On Linux you probably have one of these installed:

telnet
netcat / nc
finger

If not, it’s usually a simple sudo apt-get install finger

## OS X

Look for the commands above.

## Windows

On Windows 7 you can activate telnet.

## For all OSes

Try one of the following:

finger newyork@graph.no
echo newyork | telnet@graph.no finger
echo newyork | netcat graph.no finger

If those won’t work, try:

telnet graph.no 79

And then type “newyork”.

Have a look at the help section for more info:

finger @graph.no

Google knows where you are by default

Thu, 06 Nov 2014 00:00:00 +0000

Even if you don’t use any Goolge services directly, Google will know a lot about you. For example when using the libre web browser Firefox from Mozilla. Let me quote from their site: “We’ve always designed Firefox to protect and respect your private information.”.

When using a location service, one get the message “Would you like to share your location with <website>?” when it should really say “Would you like to share your location with Google and <website>?”. This is stated if you “Learn more…”.

This may not supprise you, as Mozilla get 90 percent of its revenue from Google, and therefore use lots of Google services out of the box.

Mozilla started their own location service over a year ago with the goal to “Improve the privacy aspects of the geolocation service compared to the current market offerings.”, which is a good thing. It can be used by following this guide. My results has been varying.

Unfortunately Mozilla isn’t as open as they could be on this. They will not share their database. I recommend using OpenWLANMap instead, as they both are older than Mozilla Location Service and do share the database.

By installing this add-on you can transparently use OpenWLANMap in Firefox instead.

You can join in collecting data for both services by using Mozilla Stubmler app or OpenWLANMap app.

I’m not aware of any positioning for web browsers that works off-line, like one can on android using Nogapps.

Nogapps - A replacement for gapps

Thu, 16 Oct 2014 00:00:00 +0000

I recently discovered nogapps, and it’s working great! Here’s an intro and how to use it.

# Background

When installing Android on a phone, one first flashes the ROM, i.e. Cyanogenmod. Then a package called gapps, which contains Googles proprietary Apps. This is necessary to get Play, Youtube, GMail, Maps, etc. And lots of apps from Play requires Play and it’s services to function.

Someone has started the project Nogapps which aims to replace some of the gapps services with open services.

As an example, you can only use GPS for location if you don’t have gapps. The other methods, wifi and cell tower id, comes from Google. Nogapps replaces this with “Network Location”. An app and a database which gives off-line location lookup.

# Installing Network Location

Before you even consider this: you need root, you need to tinker with your device. A full backup is always adviced.

Start with a phone with root access and i.e. Cyanogenmod installed. Probably works with other ROMs as well.
Download the Android SDK from Google to your PC.
This should give you access to adb, the tool to communicate with android via USB. For me the path became $ ~/Downloads/adt-bundle-linux-x86_64-20140702/sdk/platform-tools/adb
You need developer mode enabled on your phone, and to approve the computer. Not covered by this guide.
Make sure you’re connected:

$ adb devices

List of devices attached
014nnnnnnnnn800F    device

Get root access to phone, this must first be allowed in phone settings: $ adb root
Make system partition writable:

$ adb remount

remount succeeded

Download Network Location apk from the Nogapps project website and push to phone: $ adb push NetworkLocation.apk /system/app/NetworkLocation.apk
Download the cells.db for your continent from the Nogapps project website and and push to phone: $ adb push cells-europe.db /sdcard/.nogapps/cells.db
Reboot phone.

# Usage

If you’re using Privacy Guard you will be prompted the first time your phone tries to look up the location. Now make sure you’ve activated non-GPS location:

And enjoy. It works in every app:

# Contributing

If you want to contribute to the cells database, use apps like MozStumbler and OpenWLANMap.

# Further on

Nogapps consists of more that this feature, but it’s the one most important to me, and the only one I’ve tested so far.

Edit: updated 2014-10-21

Cheap DIY babycam with night vision

Tue, 30 Sep 2014 00:00:00 +0000

# Overview

When I did this project in 2012 babycams cost from NOK 2000 and up, so I decided to see if I could build one using a Raspberry Pi, an IR light and a very cheap webcam.

This will of course only be a level 0 night vision (active).

# Parts

IR LEDs with a 12V PSU.
Raspberry Pi with a 5V PSU.
Webcam. I don’t have a link to it, but pretty much any webcam will do.

# Hardware setup

I set up a test and was disappointed that the IR setup hardly gave any visible picture at all, so I threw it in the trash. Then I rememberd that all digital cameras have an IR filter to sharpen daylight pictures. To remove it I did this:

Unscrew any lense or cover.
Look for a small, slightly colored piece of glass covering the CMOS chip, and remove it by force.
Reassemble.

Now the IR seemed to light up objects several meters away. As IR light can hurt eyes, I have the light pointed towards the ceiling, so only reflected light is ever hitting people.

# Software

Installed raspbian.
Installed motion.
Webcam is now available to local network for PCs (browser, VLC) and phones (VLC, video streaming apps).

# Result

Car-logger - part 2

Mon, 29 Sep 2014 00:00:00 +0000

# Overview

Read part one of Car-logger first, if you haven’t.

I chose to go with outdated Android phones in the previous article. Phones with CyanogenMod and no Google Play. This means that they run all free software, except for some firmware blobs and drivers. No background services driving up data or battery usage, no third party tracking my location.

I tried out Traccar. The app worked fine, but the backend was a big, horrible java thing. Poor UI, overkill for my purpose, and too much for me to get hacking on.

After trying out a few different ones I finally found BigBrotherGPS. It was half of what I wanted. An app that simply makes a http request with a few parameters in post-data. The backend wasn’t more than a proof-of-concept, but http requests are easy to work with and language agnostic.

So I created BigBrotherGPSweb (a better name is needed). See github for a proper description, but the basics are:

Receive http/https requests.
Store requests and devices in mysql.
Display results in a map.

It still need some work, and I’ll be working on it until I get bored or find a new project. But it currently serves the purpose.

And of course it can be used to track more than cars.

# Edit 20140930

This requires a SIM card. My operator supplies a twin SIM for NOK 20 / month, so it’s a low cost for me.

# Pics, or it didn’t happen!

Google Hangouts - no one gets left out

Mon, 30 Jun 2014 00:00:00 +0000

… except for anyone on Firefox OS, WindowsPhone, Amazon devices, Sailfish OS and any other device without Google Play.

RadiOS part 1

Fri, 09 May 2014 00:00:00 +0000

# Overview

In my opinion most radios, especially internet radios, have horrible interfaces. Small buttons, small displays, often touch, often several functions for each button.

So Erik and I set out to design a new, better radio for ourselves. Our main requirements were ease of use and a very physical UI. Something you’d want to touch and play with.

# Platform

The Raspberry Pi is our platform of choice at the moment, so we have some physical restrictions and long boot time.

# Physical designs

## The cone

Our first idea was a cone that would rotate for volume and press down for on, next channel, off. A very basic look, and extreamly easy to use. What killed this was the size it would need to be to accomodate an rPi and the mechanical complexity of making the twist and click switch.

## Brainstorming

So we hit the whiteboard. Some of the designs from our brainstorming:

A vertical rod with the radio sliding up/down for volume.
A body-like shape hanging from the wall.
A horizontal rod, where you pick up the radio and hang it on the position of the channel you want.
Magnets! Anything with magnets!

## The chosen design

Inspired by the switch boards of early phone systems, we chose to make rows of connections where you’d short two rows to make two selections at once. One row for the channels, one for the volumes.

We went with magnets instead of jacks to make it look more modern and be quick to use.

## Software

Netradio functionality can be solved in so many ways on the command line. From the most basic:

cvlc url / aplay url / mplayer url

The medium:

Music Player Daemon

The advanced:

Musicbox

The latter one is a brilliant use of the rPi. In short it includes out of the box support for Spotify, Google Music, Last.fm, internet radio, SoundCloud, local files, files from network shares. Controlled by a webUI or any existing MPD app.

We chose Musicbox.

To be continued…

Car-logger - part 1

Tue, 22 Apr 2014 00:00:00 +0000

# Overview

I want to know where my car is. Especially if it gets stolen. Logs would be a bonus. Also, I have several outdated Android phones, which has all necessary hardware.

I don’t want to use Google (latitude) or other service providers (embedded hardware).
I don’t want to pay, unless I have to.
If possible, I’d like it to do more (explained further down).

# Hardware options

## Old android phones

Pros:

Free hardware.
Lots of sensors (GPS, compass, barometer, temperature of hardware/battery, WiFi, Bluetooth, camera, microphone).
UPS (the battery).
Low power consumption.
Reasonably small.
Can be used for calling in an emergency.

Cons:

Not as easily programmed as something running a full Linux.
Lots of apps doesn’t run on old versions of Android.

## Raspberry Pi (or similar)

Pros:

Easy to program.
Easily hook up extra gear via USB.
Can get online for free by connecting to any open network. Or even start cracking passwords.

Cons:

Cost (the Pi isn’t expensive, but with full set of attachments it may be.
Size/cable-mess.
No RTC (real-time-clock). Need network to set time after a reboot.
Power consumption.
UPS is expensive.

## Dedicated GPS logger

Like this one: Mini GSM tracker.

Pros:

Size.
Ease of use.
Battery time.

Cons:

All data is sent to an unknown company in China.
No expandability, programability.
SIM card is needed, twin SIM can not be used as calls will trigger a location report by SMS to caller.

## Conclusion

I think the phones easily wins this one for me.

# Extra features

Extra features I’d like, once I’ve decided to go with phones:

Run scanning for Open WLAN Map and/or Mozilla.
Run reporting for PressureNET if possible.
Have phone attempt to connect to open WiFis, instead of needing a SIM-card.

To be continued…

photOS 2.0 - a better photo frame

Mon, 17 Feb 2014 00:00:00 +0000

# Overview

This is about improving photOS, mentioned in http://0p.no/2014/02/14/photos1.html.

When building this, price wasn’t a factor. If you want something cheap, you can still use this software with an old laptop or other recycled hardware.

The display from Chalkboard Electronics is beautiful. Good resolution (not extreme resolution, though), good contrast, nice colors. And it supplies power for the RPi. Unfortunately it’s hard to attach stuff to it. There are nothing but smooth surfaces.

All taped up to hide backlight. What you see is a rpi, a 4-port usb hub, a thumb drive (for keeping photos on) and the power board for the display.

Using some cardboard to keep everything together. Also makes for a decent foot.

Done and placed on the table. The photo doesn’t do the screen justice.

# Hardware

Raspberry Pi
10" Touch screen
Cover made of cardboard and tape.

# Software

photOS

# Features

Sync files from ownCloud, a free, selfhosted alternative to Dropbox.
Display local images in a slideshow.
Display images from web. I.e. webcams, weather reports, RSS feeds.
Display images from reddit, i.e. lates from r/newsporn, r/wallpapers, etc.
Stream video, i.e. from baby monitor, live webcams.
Display websites, i.e. news.
Display recent images (from ownCloud), by looking at date in Exif.
Turn off LCD at night.

Here is my current crontab, to show how I’m using it:

MAILTO=****
# m h  dom mon dow   command

PHOTOS=/home/pi/photOS

#Sync owncloud
#27 7-18 * * *  ${PHOTOS}/helpers/sync-owncloud.sh

#Morning
0 6 * * *       ${PHOTOS}/helpers/powersave.sh 1; ${PHOTOS}/web/weather.sh
0 7    * * *    ${PHOTOS}/web/website.sh "http://nrk.no/tekst-tv/100/"

#Normal photo display
0  9-16 * * *   ${PHOTOS}/helpers/kill.sh; ${PHOTOS}/photos/slideshow.sh

#Display weird images from the net
0 17 * * *      ${PHOTOS}/helpers/kill.sh; ${PHOTOS}/photos/slideshow.sh $( ${PHOTOS}/web/rss-images.sh 50 )

#Baby monitor streaming
0 19,21 * * *   ${PHOTOS}/helpers/kill.sh; $PHOTOS/streams/cvlc.sh http://192.168.1.84:8081

#Night
0 1 * * *       ${PHOTOS}/helpers/powersave.sh 0; ${PHOTOS}/helpers/kill.sh;

# Challenges

The screen has no attachments. I’ve currently just taped the RPi to the back, which works but isn’t very beautiful and will break down. See “Plans”.
LXDE, the default window manager on Raspbian, has no multitouch support. The image viewer, feh, has no gesture support. I’ve looked at a few ways to use touch, but hasn’t decided on anything yet. See this Reddit post.
Feh is somewhat lacking in rotating photos correctly.

# Plans

Use touch capabilities.
3d printed or CNCed enclosure.
Display photos related to this date. I.e. if christmas, display photos from past christmases.
Look for better image viewer.

photOS version 1.0 - a place for your phone to rest

Fri, 14 Feb 2014 00:00:00 +0000

# Overview

A few years ago I wrote a collection of scripts for Debian/Ubuntu to make digital photo frames of outdated laptops. Lots of people have done this. What made photOS v.1 special was the idea that it was a place for your phone to rest. Meaning recharge, dump photos, and display photos on the big screen. All by just plugging in the power cable.

# Physical

PhotOS was conceived and designed together with littlegreenfruit, a student of industrial design at that time. I made the software, and he built a “Home Book”, a machine made for photOS. It was made using a laptop from the trash (if I remember correctly), put inside a structure of bent wood. It had a small tray to put your phones on, and retractable, textile cables (microUSB, usb and iPod connectors).

# Software

A udev rule recognized media devices and started an import script. After import, these photos was displayed.
When no recent images existed, all images collected where displayed.
At night time it displayed an animated logo of a security firm, to look like an advanced alarm system, as it was visible from outside a house entrance.
Everything was written in bash. I see no reason to publish the code, as v.2 is now published. See bottom of this post.

# Then dropbox came along

People are bad at plugging in their phone, so dropbox (and similar file syncing) made it easier to dump photos from phones. Also iPhone 4 and newer wouldn’t allow linux to pull images. So PhotOS moved to just sync dropbox and display that. Screens got better and cheaper. And the raspberry pi made it possible to build smaller and fanless.

# Version 2.0

Will come in a separate post.

Brazil-like monitor

Fri, 31 Jan 2014 00:00:00 +0000

# Overview

In the movie Brazil you can see small, mostly black/white, stripped down, CRT monitors. I’ve also seen a store having CRTs in transparent cases. Somehow I think this is a cool retro look, so I built my own. Primarily to display weather forecast by my door.

Remember CRTs uses thousands of volts, so one should keep fingers away.

# Background

A few photos from Brazil:

The store cases mentioned in overview, spotted in Denmark in 2004:

# Build process

I got a brand new crt off ebay. Unfortunately shipping from the US cost me more that the TV. I stripped it down, removed stuff I didn’t need (audio, tuner). The foot is from dx.com. The computer is a Raspberry Pi. Plastic flowers cover some of the wires and increases the WAF.

Brand new.

Away with the cover.

# Code

Weather is from finger oslo@graph.no. It alternates between showing hour by hour for a 24 hour period, and a large weather-right-now with unicode images of sun, snow, etc. There are a few more scripts to test network and such.

Right now looks like this (your browser will have to have unicode support):

-3℃ ☃⚐
⌚11:50

# Future plan

Cables from CRT to main board are very short. Will replace them with some colored fabric cables. This will also allow the arm to hang below shelf, as originally planned.

Checklist for Raspberry Pi setup

Sun, 19 Jan 2014 00:00:00 +0000

# Overview

There are lot of small changes one should do for pis that will be in use over some time. I covered a few in Keeping A Raspberry Pi Alive. This post will serve as more of a complete checklist for myself, so it may be updated over time.

# Basic stuff

Update:

sudo apt-get update; sudo apt-get dist-upgrade

Get some necessary tools:

sudo apt-get install screen mosh

Set locale, password, a unique hostname, etc:

sudo raspi-config

Change autostart. You might want to comment out screensaver, and add your own stuff:

sudo nano /etc/xdg/lxsession/LXDE/autostart

Completely disable screensaver. Under [SeatDefaults] add “xserver-command=X -s 0 dpms” in following file:

sudo nano /etc/lightdm/lightdm.conf

# If you’re using an SD card as main storage

Put /tmp on tmpfs: Edit /etc/default/tmpfs and set: RAMTMP=yes.

Put log on tmpfs: Install fs2ram, version 0.3.12 or better. Earlier versions are broken in Debian. http://packages.debian.org/unstable/main/fs2ram. Edit /etc/fs2ram.conf, activate /var/log and /var/tmp.

Consider locking /boot to read-only:

TODO!

# If you’re using wifi

## Set up wifi

Edit /etc/wpa_supplicant/wpa_supplicant.conf:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
 ssid="network-name"
 psk="password"
 priority=1
 id_str="network-name"
}

# If you’re using raspicam

Disable led on camera:

sudo echo 'disable_camera_led=1' >> /boot/config.txt

# When you’re done

Set up backup and get to work! =)

# Edits

Edit: 20140120 - added section on camera.
Edit: 20140131 - added more info on autostart, screensaver.
Edit: 20141118 - removed outdated wifi stuff.

Fanless livingroom entertainment

Wed, 08 Jan 2014 00:00:00 +0000

# Background

I recently made an effort to keep only fanless (or silent) devices in my livingroom. Including my media center / HTPC. This article will outline a few ways to achieve this.

# Requirements for setup

## Must have

File/torrent downloading with decent storage.
Playback of movies, music and images.
Very low noise levels, especially when not in use.

## Should have

Youtube.
Spotify or similar legal music service.
Play/control from smart phone.
High Wife Acceptance Factor.
Low maintenance.

## Nice to have

Netflix, HBO or similar legal video service. (This is unlikely in my scenario, as they don’t support my OS of choice.)

# Suggested setups

## The all-in-one HTPC

Schematics:

+--------------+
|              |
|              |              +----+
|  TV          |              |    |         +-+
|              | --- HDMI --- | PC |  - - -  |A| <- (Smart phone)
|              |              |    |         +-+
+--------------+              +----+

This is the most common. A desktop or laptop connected to the TV. Preferably small and quiet. Either running media center software controlled by a smart phone over wifi, or running a standard desktop and controlled by a wireless keyboard/mouse.

Pros:

Easy to set up.
You probably have the needed hardware.
Flexible (you can use any app, browser, netflix compatibility layer, etc).

Cons:

Low WAF.
High maintenance.
Often noisy.
Large space requirements.

## The raspberry pi

A raspberry pi is used instead of the PC, with Raspbian or similar.

Schematics:

+--------------+
|              |
|              |
|  TV          |              +----+         +-+
|              | --- HDMI --- | Pi |  - - -  |A| <- (Smart phone)
|              |              +----+         +-+
+--------------+                |
                                USB
                                 |
                               +-----+
                               | HDD | <- (Or thumb drive)
                               +-----+

Pros:

Cheap.
No fans, no HDDs (unless you add one).
Small. Can be hidden anywhere. Can even be brought along on travel.

Cons:

You need some familiarity with the pi to set it up.
Starting playback and navigation is slow.
No support for netflix, HBO. Bad support for spotify.
You need to add storage. A large thumb drive will do fine. If you use an external hard drive, you will have to power it by something else than the pi.

Problems that can be handled:

Spotify app for xbmc is cumbersome => install mopidy instead, or use a separate pi with MusicBox for music.

## Raspberry Pi + a good router

Same as above, but HDD is attached and shared from the router. This separates downloading from playback to improve performance and because the router will usually be able to power a 2.5" HDD.

Firmware like Tomato or OpenWRT can run Transmission for downloading and share files using Samba or UPNP.

This setup can also be solved by using an extra Pi instead of the router.

Schematics:

+--------------+
|              |
|              |
|  TV          |              +----+         +-+
|              | --- HDMI --- | Pi |  - - -  |A| <- (Smart phone)
|              |              +----+         +-+
+--------------+

                              |
                              |
                           +--------+             +-----+
                           | Router | --- USB --- | HDD |
                           +--------+             +-----+

## Smart TV + storage

I’m not a fan of smart TVs for several reasons:

They are usually slow and complex.
They seldom receive software updates, and are therefore full of security problems.
You can’t upgrade your “HTPC”, since it’s part of the display.

But if you have one, you can add storage to it to allow for a noise less livingroom.

Schematics:

+--------------+
|              | --- USB --- Thumb drive or HDD
|              |
|  Smart TV    | - - - Storage (router, Pi or PC)
|              |
+--------------+

Pros:

You get some value from your overly expensive, over-engineered display.
Very little cables, mess. High WAF.

Cons:

Codec support is limited.
No automatic download of subtitles, like XBMC does.
Use limited to what ever apps are available for your TV.
Usually a horrible UI.

Androids privacy invasiveness

Tue, 31 Dec 2013 00:00:00 +0000

# Overview

With Android you have two options of app management. With Google Play, or without. As Google is getting more and more invasive the latter option seems more tempting. Too bad they made sure it’s a poor one.

# Background

Each device manufacturer that wants to include Play has to include a bundle of Google apps, gapps. And if he ever release a device with a competing app store (i.e F-droid, Amazon Appstore), he will be banned from future use of Play.

What control does Play give Google? Full remote access! What does it take away? The option to uninstall any of the closed source gapps. Examples of this access can be seen when installing apps via the website play.google.com (no user interaction required) or in the Android Device Manager that suddenly turned up on every device. It allows you to track a phone, without ever having enabled (or been notified of) this on the device. I’m sure it’s in the EULA somewhere, but it was unknown to me until it appeared in the news.

On xda-developers forum you can see that the absolute minimum of apps you can choose is Core Base, Google Experience Launcher, Google Bookmark Sync, and the following Play Store applications: Gmail | Google+ | Google Calendar (replaces stock/AOSP Calendar) | Google Play services | Google Search | Google Text-to-Speech | Hangouts | Maps | Street View on Google Maps | YouTube. Not only are they all installed, but some of them will also bug you to use them. Like G+ Photos, which pops up and tempts me with free, secure and private storage, or creates animated gifs of my photos without me asking for it.

The by far biggest problem though, is that most of the apps in existence are only available in Play. If you don’t have play, you can’t have i.e. Spotify.

# Other issues with gapps

They’re all closed source.
No one of them allows you to adjust how they sync. You can’t tell gmail to sync mail only when on wifi, or stop syncing when your battery is low.
Some of them duplicate functionality. Like G+ Photos vs. Gallery.

George Washingdone - a motion sensor for your washing machine

Mon, 16 Dec 2013 00:00:00 +0000

# Overview

When PiBorg launched the accelerometer/compass XloBorg, I imediately bought a couple. I had no idea what to use them for, but the price was right, raspberry pi was new, and it seemed like a fun “sensor” to play with. It remained in my drawer until this weekend. Over a few hours at a hackathon I created the WashingDone. A script to measure certain patterns of motion, to alert when the washing machine is done.

It is still under testing, but it seems to work. Just need to find the right values for motion, calmness, required duration of motion, etc. See project page/github for source.

Android with as little closed source as possible

Mon, 25 Nov 2013 00:00:00 +0000

# Overview

Android seemed like an OpenMoko.org that could work. A phone running free software. Linux, and all the goodies that goes with it. However it took a bad turn. Not only was it just linux (no GNU), but Google seems to be locking it down. Replacing every app with a closed source one: Googles iron grip on Android.

See follow-up: Android with as little closed source as possible 2.

This problem can be broken into three:

## Hardware (closed drivers)

Possible solution: FairPhone?

## Android is not GNU/linux

Android missing GNU tools, crontab, rsync, mosh, apt and other components making Linux fun to use. Possible solution: I don’t have one for this. Perhaps Sailfish OS or Firefox OS? This isn’t a big problem, though.

## Software (closed source, reliant on Google services)

Possible solution: Replicant is “a fully free Android distribution running on several devices”. It can be a long-term solution for this, but has some issues. It doesn’t have access to source for drivers (camera, GPS, modem ++) on most phones, and there are lots of apps that one only can find in Google Play. I don’t understand why companies allow Google to control all of their business and push apps to Google Play only. However, I’m reliant on a few of these apps (Spotify, RuterBillett, etc.), so I’ll have to keep Play for now.

I’ve made a list of how I’m keeping as little closed source on my phone as possible. As of 2013 this is my setup:

Rom: CyanogenMod with Privacy Guard enabled.
Anything from AOSP is OK. That includes the default app for calendar, messages, calling.
App store: F-droid
E-mail: K-9
Podcast: AntennaPod
Browser: Default is OK, but there are several good alternatives including Firefox and Lightning
Task sync: aCal
Reddit: RedReader
Facebook if you must: Tinfoil for Facebook

These are some good, open source apps, but unfortunately only available through Play:

TextSecure - SMS encryption
RedPhone - VOIP encryption

Apps/services I’ve yet to find a replacement for:

Google maps
Yatse
Youtube
TinyCam monitor free

Hello world

Mon, 25 Nov 2013 00:00:00 +0000

Keeping a Raspberry Pi alive

Mon, 25 Nov 2013 00:00:00 +0000

# Overview

http://raspberrypi.org is a great, cheap piece of hardware, but it has some limitations. Number one is the SD card. SD cards are not made for lots of rewrites to the same file.

Edit 20140109: If you wonder why SD cards suck, see http://www.youtube.com/watch?v=r3GDPwIuRKI.

# Tricks to prolong the life of the SD-card

Edit /etc/default/tmpfs and set: RAMTMP=yes. This will keep /tmp in memory.
Install fs2ram, version 0.3.12 or better. Earlier versions are broken in Debian. http://packages.debian.org/unstable/main/fs2ram. In its config it’s important to activate /var/log and /var/tmp. If you’re using any databases or other files that are written to often, make sure they’re on a tmpfs using fs2ram. If you keep /var/cache in memory, make sure to clear out apts cache often, as it can fill up: sudo apt-get clean
Disable swap: sudo dphys-swapfile swap off, and uninstall it: sudo apt-get remove --purge dphys-swapfile

Life without US cloud services

Mon, 25 Nov 2013 00:00:00 +0000

# Overview

I’m not creating this list because I have something against the US or because I hate the cloud (or to get on a watchlist). I’m creating it because my work/hobbies. Also for economy, access to resources (unlimited dropbox!), performance (keep things local) interest in FLOSS and control of my data.

# Why?

As Snowden showed the world how much interest NSA takes in foreigners, I’ve started migrating my data away from the US cloud. This isn’t easy, as you would know. Here are the alternatives I’ve moved to.

Dropbox -> ownCloud (not production ready for large collections)
Google search -> startpage.com
Google contact sync -> ownCloud with DAVdroid
Google calendar sync -> DAVdroid
Google todo-list -> ownCloud with aCal (no offline use yet =(
Google mail -> I use Runbox, but I’m sure there are lots of non-US, security conscious e-mail providers. You have to pay for e-mail, but it’s not much.
Google Hangouts -> Self hosted Jabber server. But there are public servers listed on Jabber.org
Google Reader -> Tiny tiny RSS or ownCloud
Image sharing (facebook, g+, flickr) -> ownCloud, but not perfect yet.

Edit: updated list 20131211