Infrared remote for HiFiBerry

There are situations where it is not very convenient to use the phone or tablet to control the music. Sometimes you just need to quickly change the volume, pause the playback or skip a song on a playlist, and this can be done much easier using a IR remote.

Adding an infrared remote to the Raspberry Pi is very simple. This story is a continuation of the previous blog post about multi-room audio. It enhances the functionality and allows you to control volume instantly with a simple remote, without to have a phone or tablet with an app open with you. All you need is just a TSOP38238, an IR receiver module for remote control systems which is a component that converts IR signal into electrical pulses that will go to GPIO digital input of the Pi. Then you also need a HW remote, you can use some spare you have at home, or buy a one that suits your purpose. For my family I decided to use small and simple remotes from Apple purchased on eBay. These are very tiny with just few basic functions, and especially for the kids these are easy to use. And finally there is a utility called LIRC (Linux Infrared Remote Control) which is a package that allows you to decode and send infra-red signals of many commonly used remote controls. 

How to do it step by step

1) HW preparation, obtain a TSOP38238 module (around 0.5 EUR a piece)

2) According to the datasheet connect the module to 3.3V, GND and GPIO 25 (Pin 22). The GPIO number might be different depending on your other HW you use with your Raspberry. For HiFiBerry audio boards please refer to this page to find an unused pin. GPIO 25 works well with HiFiBerry AMP2. I do not recommend direct soldering to the board as you might lose the warranty, pin connectors are recommended here.

3) Check again the wiring with the diagram and power on the Raspberry

4) Go to the web Max2Play config, enable LIRC support on Raspberry Settings tab and set the right GPIO IN 

Save! 

5) Reboot needed.

6) Remotely connect to your Raspberry Pi From Windows for example:

• Start cmd
• ssh user@yourhifiberry (“pi” is the default in Max2Play setup)
• pass: (default password is “max2play”)  

7) Now log as a superuser

• su - 
• pass: (password needs to be defined in the web console if you don’t know it) 

Now you can use the Midnight Commander and its quick and easy built-in editor, or command line and VI if you prefer. 

8) Update the following lines in /etc/lirc/lirc_options.conf 

• driver    = default  
• device    = /dev/lirc0  ??  or auto

9) Check your HW is working properly and pulses are being recognized 

To test if  lirc driver is working:

• $ sudo /etc/init.d/lircd stop 
• $ mode2 -d /dev/lirc0  

Press a key in remote and you should see multiple lines like below: 

pulse 560
space 1706
pulse 535
…  

10) /etc/lirc/lircd.conf  Here the remote commands needs to be specified for your custom remote (each remote requires different config) you can tweak the command mapping here. See mine below for Apple remote.

# this config file was automatically generated
# using lirc-0.8.1(iguanaIR) on Fri Mar 30 19:20:40 2007
#
# contributed by Matthias Urlichs <matthias|urlichs.de>
#
# brand:                       Apple
# model no. of remote control: A1156
# devices being controlled by this remote: new (late 2006) MacBook
#
# This config files are for non-Apple receivers only.
# Use the lircd.conf.macmini file when you are using the Apple receiver.
#

begin remote
  name  Apple_A1156
  bits            8
  flags SPACE_ENC
  eps            30
  aeps          100
    
  header       9065  4484
  one           574  1668
  zero          574   547
  ptrail        567
  repeat       9031  2242
  pre_data_bits   16
  pre_data       0x77E1
  post_data_bits  8
  post_data      0xC5
  gap          37600
  toggle_bit      0
  ignore_mask 0x80ff

      begin codes
          KEY_PAUSE                0x20                   #  Was: play
          KEY_VOLUMEUP             0xD0
          KEY_NEXT                 0xE0                   #  Was: ffwd
          KEY_PREVIOUS             0x10
          KEY_VOLUMEDOWN           0xB0                   #  Was: minus
          KEY_POWER                0x40                   #  Was: menu
      end codes

end remote

11) Add the support into Squeezelite by adding “-I” switch (see here) in Audioplayer/Advanced options, and check update squeezelite and save. 

12) Wait until the update procedure finishes, it takes about 4 minutes to complete. Reboot now message will appear at the end of the yellow messaging dialog. Reboot.

13) Test the remote, it should be working now. If not, the commands are not properly set in the /etc/lirc/lircd.conf 

Now you should be able to use the remote as an additional controller.