So I have been building a few portable things with Raspberry Pi Zero lately and I’ve been using the Adafruit PowerBoost board. Its a great board for bumping a 3.7V LiPo battery output up to 5.2V for running Raspberry Pi projects, plus it handles charging, has low battery detection and you can turn off the output with a pin. The only problem was being able to do a safe shutdown and then use a pin from the Pi to cut the power. I’m kind of surprised there isn’t a board and prebuilt solution for this and it took a lot of research before I came across NeonHorizons LipoPi repository. The functionality I was after was in the Power Up/ Power Down version and I used the ‘Simple Press’ section as the basis of my circuit. I was using the Adafruit Speaker Bonnet for my project so I could not use the suggested pin 18 and changed it to 27, but the rest stayed the same. Anyway, I put the suggested circuit onto some strip board and the solution worked perfectly so kudos and thanks to Daniel Bull. Check out the repo for the code, instructions and circuit diagrams, my circuit is below.
SpotiPi
I’ve been getting friendly with the Raspberry Pi Zero for audio applications and I discovered some great new boards just before Christmas by Pimoroni that include a DAC, a screen and some buttons. My son loves his music but is at that age that if you give him a device to play Spotify on he will just fiddle with the device so I wanted to give him a Spotify player without the distractions and something he can have a little party with his friends. I came up with this little boom box in gold and black that displays the album art and gives you volume control, play, pause and skip buttons, is USB rechargeable has great sound quality, is pretty loud and has a long battery life. I can select a playlist on my phone and then he can take it away. Also clear front panel so he can check out all the circuitry and room for adding some more buttons and faders!
Sound Fragments
I have been working on some Raspberry Pi powered speakers for a while now. These devices owe a lot to the interactive bird sculptures that I made for Forest of Imagination in 2018. The devices have a decent speaker and amplifier, battery, are USB chargeable with exposed volume controls and can communicate with one another. Right now I am running PD on them to generate sounds and hope to add functionality for other inputs and outputs such as sensors, microphone and LEDs. The idea really was to be able to create a network of smart devices capable of producing decent quality sound for sonic art installations.
Eventually I hope to make this project open source and share the code, designs and bill of materials on line.
