This project implements a simple internet-radio using
- a Raspberry Pi (or a similar SBC)
- a TTP229-based keypad and/or
- an infrared remote-control
- a LCD-display (typically with 2-4 rows and 16-20 columns)
Basic features of the implementation:
- select predefined radio-stations using the keypad/remote
- display date and time and channel name on the display
- display ICY-META data on the display
- record a radio-channel (either unattended or on request)
- playback recordings
This project assumes that you have a basic installation of Raspbian (or a similar OS, e.g. Armbian on other platforms). You should have successfully configured sound. You should also know how to connect a LCD display using the I2C-interface and the keypad to your Pi. For the LCD you will find many tutorials on the net, for the keypad you should head over to my pi-ttp229-keypad project.
As an alternative for the keypad you can use a remote-control and configure LIRC for it. There are also a lot of tutorials available on how to configure LIRC for Raspbian.
If you connect your Pi using HDMI to a receiver, you can also use CEC (Consumer Electronics Control). This delegates a number of commands (volume, mute) directly to the receiver. See the section about CEC below.
Note: using only the recorder-part of the project does not require the display and the keypad - even the configuration of the sound-system is not necessary as long as you use a different system for playback. So the recorder can be operated on a pure headless system.
Use the following commands to install the software and all prerequisites:
git clone https://github.com/bablokb/pi-ttp229-keypad.git
cd pi-ttp229-keypad
sudo tools/install
cd ..
git clone https://github.com/bablokb/simple-radio.git
cd simple-radio
sudo tools/install pi 27
The firt set of commands installs the code for the keypad, the second set
installs the code of this project. If your standard user is not pi,
you should pass a different name to the install command. The install command
also needs the number of the GPIO-pin of your LIRC installation. Even if
you do not use a remote, you have to provide this number.
Both installations will ask you to configure the software using the files
/etc/ttp229-keypad.conf and /etc/simple-radio.conf respectively.
If you want to use CEC, follow the additional installation instructions below.
Alternatively, for a pure headless installation use:
git clone https://github.com/bablokb/simple-radio.git
cd simple-radio
sudo tools/install-headless pi
Again, change the user pi to a suitable value on your system.
The config-file of this project (/etc/simple-radio.conf) has a number of
sections. The meaning of the sections and variables should in general be
clear.
The [GLOBAL] section configures some basic properties. The section
[DISPLAY] lists the attributes (rows and columns) of your
display. Not every display has all the characters at the correct
code-points, you can use to translate characters to the correct
codepoint with the trans-variable:
trans: äöüßÄÖÜíáéè, e1,ef,f5,e2,e1,ef,f5,69,61,65,65
This variable holds a comma-separated list of strings. The first string
contains all special characters, the rest are the relevant replacement
code-points. For every character in the first string you need a
replacement point. The installation provides a little script show_charset.py,
this will display all code-points:
show_charset.py 0 1 2 3
will display chars 0-15 and so on.
The section [RECORD] defines the default target-directory for recordings
and the default duration. Both values can be overriden on the commandline.
The default duration prevents that your SD-card is filled with a very
long recording in case you forget to stop the recording.
The [KEYPAD]-section defines the mapping of the 16 keys to predefined
commands. For every key, you can map the function in radio-mode and in
player-mode.
The example maps the first 8 keys to switch_channel in radio-mode, i.e.
key 5 will switch to channel number 5 (see below).
In player-mode, the keys trigger other functions, e.g. start/stop playing or switching to the next recording.
The configuration file has a list of all available commands you can match to the keys. Also see the section "Functions" below.
Finally, the [LIRC]-section maps LIRC-keynames to functions. Since remotes
typically have more keys, every key is only mapped to a single function.
During startup, the program loads a simple list of radio-channels from
the file defined in variable [GLOBAL] -> channel_file. The default filename
is /home/pi/simple-radio.channels (replace pi with the name of your user
you passed to the install-command). The file should contain lines in
the format
name@url
e.g.
Bayern 3@http://br-br3-live.cast.addradio.de/br/br3/live/mp3/128/stream.mp3
Note the blank in the name-part (this is supported), but name should not
contain a @. The maximum length of name is 10 on a display with 16 columns
and 14 on a display with 20 columns.
The mapping to channel numbers is straightforward: the first line defines channel 1, the second line channel 2 and so on.
The install-script copies a sample channel file from
examples/simple-radio.channels to the home-directory of the user passed
to the install-command. The sample channels-file contains a number
of public radio channels in Germany. Note that the URLs are not
stable and tend to change over time.
The program implements a number of functions which can be mapped to keys:
| Function | Description |
|---|---|
| switch_channel | switch to channel (channel-number = key-number) |
| prev_channel | switch to previous channel |
| next_channel | switch to next channel |
| toggle_record | toggle recording, i.e. start or stop recording |
| radio_off | turn the radio off (a recording will continue) |
| --------------- | ----------------------------------------------------- |
| volume_down | decrease volume |
| toggle_mute | toggle mute (not available with all sound-hardware) |
| volume_up | increase volume |
| --------------- | ----------------------------------------------------- |
| start_playmode | switch to playback-mode |
| prev_recording | switch to the previous recording |
| toggle_play | start or pause the currently selected recording |
| next_recording | switch to the next recording |
| stop_play | stop the current playback |
| exit_playmode | switch back to radio-mode |
| --------------- | ----------------------------------------------------- |
| reboot | reboot the system |
| restart | restart the application |
| shutdown | shutdown the system |
| --------------- | ----------------------------------------------------- |
Simple-radio supports ad-hoc recordings using the function toggle_record,
which is bound to key 15 in the default settings. During a recording,
you can switch to a different channel or turn the radio off (you should
not shut it down though). To prevent full sd-cards, the recording time
of ad-hoc recordings is limited by the value of the configuration-variable
duration in section [RECORD].
Besides these ad-hoc recordings, simple-radio also supports recordings in headless-mode directly from the commandline, e.g.
simple-radio.py -r 4 120
will start to record channel "4" for 120 minutes. Using at or cron you plan one-time or regular recordings, e.g.
echo /usr/local/bin/simple-radio.py -r 4 120 | at 20:00
will start the recording today at 20:00. Note that "at" is not installed by default on Raspbian.
For repeated recordings, you can use an entry within crontab, e.g.
5 8 * * 7 pi /usr/local/bin/simple-radio.py -r 4 55
will record channel 4 for 55 minutes every Sunday at 08:05.
The program uses CEC to delegate a number of functions (currently only volume-up, volume-down and mute) to a receiver. Prerequisite is that your Pi is attached to a receiver using HDMI and that you install CEC-support.
The version of libcec installed by Raspbian (at least up to Stretch) is not suitable, since it does not install the Python-wrappers. So you must install libcec yourself.
First, you should remove the relevant packages if already installed from the repository:
sudo apt-get -y remove libcec cec-utils
sudo apt-get -y autoremove
As a second step, you should edit the script tools/mk-libcec if you
compile on a Pi2 or Pi3. In this case, you should use the line
make -j4 instead of just make (the third-last line in the script).
Download and compilation takes about a quarter of an hour on a Pi-Zero, but this depends of course on the speed of your internet connection.
To test CEC-support, you can run tools/cec-test.py. This script
registers itself as a tuner on the CEC-bus and then runs a sort of
shell, waiting for the user to enter commands, e.g. scan. Have a look
at the source code to check possbile commands. You should also use the
remote of your TV or receiver and see if the test-programm successfully
picks up commands or keys.
To activate CEC for simple-radio, you have to change the variable cec
within section [GLOBAL] in the configuration file /etc/simple-radio.conf.
More is not necessary. After a restart volume-changes and muting should be
delegated to your receiver/TV.
A note on hacking:
CEC-support could be extended to more functions if the remote of your
receiver or TV has better CEC-integration. In this case, you should
start with the method _process_key() within the file
files/usr/local/bin/SRCec.py. Here you have to map keys to the
relevant functions of simple-radio. See file files/usr/local/bin/SRKeypad.py
(method process_key()) for a sample implementation.