Transistor

Deprecation status

This version is for the Raspberry Pi Zero W version 1 only.
It was the first version of the Transistor software.
It is not maintained any more but should work as described here.
You can download it here: https://github.com/pirateradiohack/Transistor/releases/download/2022-04-10-Fix_Podcasts_Update-SSH/image_2022-04-10-Transistor-lite.zip

Development efforts are being made in the new repository (https://github.com/pirateradiohack/Transistor) to support the Raspberry Pi Zero W version 2, and if possible also the version 1.

This repository will be kept in its current state.

Build your own radio set and listen to web radios, podcasts and bluetooth.

🇬🇧 Quick Setup + User Manual
🇫🇷 Manuel de mise en route et d'utilisation

All you need to do is copy the image to a micro SD card and insert it in the following hardware:

• Raspberry Pi Zero W
• Micro SD card (4GB should be enough if you don't want to store anything on it. If you want to store music or podcasts on your device then the bigger the better.)
• Pirate Audio 3W Stereo Amp
• A pair of 5W 4 Ohm 65mm Full Range Speaker
• On / Off switch
• Colourful Arcade Buttons (For the Big Next Button(TM) )
• Tactile Switch Buttons (For the power button)
• USB A to microB cable - Red – 10cm (To connect the On / Off switch power micro USB to the battery charger.)
• Adafruit PowerBoost 1000 Charger - Rechargeable 5V Lipo USB Boost @ 1A - 1000C
• LiPo Battery Pack – 2000mAh (more mAh means more autonomy, bigger is better but also more expensive)
• Right-angle Panel Mount Extension Cables (25cm) – USB micro-B (To connect to the battery charger and provide a power plug that goes outside the radio.)
• [optional] RasPiO Analog Zero (Optional. If you plug it, you will be able to use an old radio volume knob out of the box!)

(if you find better hardware parts please tell me!)

Get the components, assemble them together and build the case with a 3D printer:

• Case
• Back Cover

(You will need to adapt the battery compartment to fit you own battery.)

Alternatively you could use your own case, or an old radio, or a cardboard box, or a wooden box, or a toaster...

Quick Setup

• Download the latest image, that's the ZIP file named image. Unzip it.
• Flash the image with etcher.
• Install the SD card in your radio and turn it on. (note that the first boot takes some time, be patient)
• You will see a new wifi access point called Transistor: connect to it (the password is Transistor). In your browser, open http://192.168.179.1:8000/wifi_settings (it can take some time to load, be patient) and enter your home wifi name and password there. Press OK, your Transistor will reboot and connect to your wifi.
• Connect to the web interface: hold the play / pause button and you will see the IP address of the Transistor appear on its screen. Copy that to your browser. (If that does not work on your device then read Controlling your Transistor)
• From the interface, add a radio to listen to by going to +Radio in the menu.
• Enjoy.

Features Description:

* Play web radios:

From the web interface, click the +Radio button and enter the name of the radio. Wait a bit, it will be added automatically to your list! (thanks to radio-browser.info). (Optionally you can add an http radio stream directly with the +Stream button.)

* Play your podcasts:

From the web interface, click the +Podcast button to go to the podcasts settings where you can subscribe and manage your podcasts. Podcasts are then updated every 30 minutes. Only the latest number of episodes you specify will be kept on your device and appear in the Podcasts section automatically. (Do note that it takes time to download the episodes. Try to subscribe gently and allow some time before subscribing to other podcasts.)

* Bluetooth speaker:

Simply connect to the bluetooth speaker called Transistor from your phone or computer.

* Sleep timer:

When you hold the on / off button for 1 second your Transistor will turn off 20 minutes later. If you feel the need, you can hold it again to add another 20 minutes and so on, until you fall asleep. (You can still simply press the on/off button to immediately turn off your Transistor.)

* The BiG NexT ButtoN (TM):

A big, very satisfying to hit, arcade style button that skips to the next radio. Feels Good.

Images:

Inside:

The web interface:

Detailed setup

Getting the image

Ready-to-write image

For your convenience you will find the latest image pre-built. Access it from the releases page. Download and unzip the latest image, it's the zip file called "image" with a date. (It is built automatically from the source code by Travis-ci.)

In case you would like to set your wifi manually, the file to edit is: /etc/wpa_supplicant/wpa_supplicant-wlan0.conf (edit this file as root / sudo)

Your operating system needs to be able to mount ext4 (linux) partitions. You can edit the files before or after writing the image to the sd card:

• before: you can mount the .img.
  With a modern operating system you probably just have to click the .img.
  With Linux you can use kpartx (from the multipath-tools package) to be able to mount the partition directly: sudo kpartx -a path/to/2019-05-23-Transistor-lite.img followed by sudo mount /dev/mapper/loop0p2 tmp/ -o loop,rw
  (you will need to create the mount directory first and check what loop device you are using with sudo kpartx -l path/to/2019-05-23-Transistor-lite.img). Then you can edit the files mentioned above. And sudo umount tmp.
  You are safe to flash the image.
• after: your operating system probably automounts the partitions.

building from source

• First clone this repository with git clone https://github.com/pirateradiohack/Transistor.git.
• Then build the image. (You can see the whole guide on the official RaspberryPi repo: https://github.com/RPi-Distro/pi-gen). I find it easier to use docker (obviously you need to have docker installed on your system) as there is nothing else to install, just run one command from this directory: ./build-docker.sh. That's it. On my computer it takes between 15 and 30 minutes. And at the end you should see something like: Done! Your image(s) should be in deploy/
  If you don't see that, it's probably that the build failed. It happens to me sometimes for no reason and I find that just re-launching the build with CONTINUE=1 ./build-docker.sh finishes the build correctly.
• On some systems even Docker fails to build the image. In this case you can fallback to Vagrant. It will create a virtual machine with a supported OS to build the image. You will need to install both Vagrant and VirtualBox. The vagrantfile at the root of this repository will install Debian Buster as recommend by pi-gen. It will also share the repository inside the VM at /pigen. It means you just need to issue those commands: vagrant up then vagrant ssh --command 'sudo /pigen/build.sh' and finally vagrant halt. If everything goes well you will find your image in the deploy folder.
• You should find the newly created image in the deploy directory.

Write the image to a SD card

Now that you have your image file, you need to write it to a SD card in order to put it in the Raspberry Pi. Choose you favorite method below and once you have your SD card ready you can boot your Raspberry Pi, the first boot can take a minute or two, and then your radio is ready to go.

graphically

For a user friendly experience you can try etcher to flash the image to the SD card.

manually

On linux (and it probably works on Mac too) an example to get it on the SD card would be:
sudo dd bs=4M if=deploy/2019-05-23-Piradio-lite.img of=/dev/mmcblk0 conv=fsync (of course you need to replace /dev/mmcblk0 with the path to your own SD card. You can find it with the command lsblk -f) Those settings are recommended by the RaspberryPi instructions.

Controlling your Transistor

Transistor is equipped with the necessary buttons to turn it on / off, control the volume up and down, and select the next and previous radio stations. Besides that, you can control it remotely, on the network.

Transistor connects to the wifi network that was set in the config file. It should receive an IP address from the Internet router. You need to find this IP address in order to control the Transistor. There are several ways you can do that:

• For convinience, Transistor sets its own local domain. Some devices are compatible with this (Android supposedly works, but iOS does not. Linux should be fine if avahi is installed). So you can try to reach your Transistor at the address transistor.local.
• You can see the IP address of your Transistor directly on its screen when you hold the play / pause button.
• The command nmap 192.168.1.0/24 can list the devices on your network (adapt the network address based on your computer's IP address, most probably the 1 could be another number). You will see a device named transistor.local along with its IP address.
• Or you could also check your Internet router to get the list of connected devices and their corresponding IP addresses.

via web interface

You can control your radio via web interface: try to open http://transistor.local (or the IP address) in a web browser.

via ssh with a terminal interface

If you prefer the command line, you can ssh into Transistor and then use ncmpcpp to get a nice terminal interface (see some screenshots here: https://rybczak.net/ncmpcpp/screenshots/).

via an application

You can use any mpd client you like (a non exhaustive list of applications for various platforms can be found here: https://www.musicpd.org/clients/). If you are asked for the port number, it's the default one, 6600. And for the IP address, it's the same thing as above.

How it is built

The image is built with the official RaspberryPi.org tool (https://github.com/RPi-Distro/pi-gen) to build a Raspbian lite system with all the software needed to have a working internet radio stream client. It uses mpd.

Developers

The most interesting bits happen in the stage2/04-pirate-radio directory. Where files can be added and then instructions can be set for the building tool to create the final OS image.

If you want to test the image locally, without the need to burn it to an SD card, you can use QEMU to emulate the hardware on your system and then create a virtual machine.

• Make sure you have QEMU installed for the arm architecture, you can test with qemu-system-arm --version.
• Set USE_QEMU to "1" or true in the config file and then build your image as usual.
• Download the Buster kernel and the Device Tree File in the deploy directory.
• Execute qemu-system-arm -kernel kernel-qemu-4.19.50-buster -cpu arm1176 -m 256 -M versatilepb -dtb versatile-pb.dtb -no-reboot -serial stdio -net nic -net user,hostfwd=tcp::2222-:22,hostfwd=tcp::2223-:80 -append "root=/dev/sda2 panic=1 rootfstype=ext4 rw" -hda name_of_your_image

That should boot the image. You can then ssh into it on localhost on port 2222, and use port 80 on localhost port 2223.

Hardware

This is the detailed usage of the pins (thanks to https://pinout.xyz). This is mostly of interest when you want to connect the buttons.

OOS: On Off Shim
AZ: Raspio Analog Zero
PA: Pirate Audio Amp + LCD

Powers and grounds don't appear in the picture, here is their pinout:

• Power 1: OOS / AZ
• Power 2: OOS / PA
• Ground 6: AZ
• Ground 9: AZ
• Ground 14: AZ
• Ground 20: AZ
• Ground 25: AZ / PA
• Ground 30: AZ
• Ground 34: AZ
• Ground 39: AZ / PA

The first channel of the Raspio Analog Zero (channel 0) is expecting to receive a potentiometer to set the sound volume: plug the ends of the potentiometer to 3.3v and ground, then plug the wiper (usually found in the middle of the three tabs) into the first channel of the Analog Zero.

These are the instructions to generate the image of the pins layout:

• cd to pinout directory
• edit src/en/overlay/transistor.md
• docker build -t pinout.xyz .
• docker run -p 5000:5000 -e PINOUT_LANG=en pinout.xyz
• in browser open http://localhost:5000/pinout/transistor
• docker stop container_name
• docker rm container_name
• docker rmi pinout.xyz

Contribution

Issues and pull requests are welcome.