The circuit diagram above shows the connections for the power and audio. The lengths of the connections are not exact and mostly ment to visually represent which pin goes where. It's best to use this as a reference for pins.
The slide switch is wired to pin GND and EN. The 2000mAh lithium polymer battery is connected to the JST port. The #2(5V) and #6(GND) connections represent the wire number from the Pi ribbon cable.
The VIN and GND pins are wired to the 5V and GND pins on the powerboost 1000c. The A+ and A- pins are wired directly to the audio pins on the bottom of the Raspberry Pi A+. The speaker is wired to the amps audio output (+ and -).
To interface the Pi with the tactile buttons, we'll use a Pi ribbon cable (26 pin). The connections below indicate the wire number, gpio name and keyboard input controller button. The White colored wire will be represented as Wire #1. The blue connections indicate the ground for each buttons. These are all wired to the bottom ground rail.
- Wire # 2 - 5V Powerboost
- Wire # 6 - GND Powerboost
- Wire # 7 (GPIO 4) - Key Left
- Wire # 9 - Ground for Buttons PCB
- Wire # 11 (GPIO 17) - Key Right
- Wire # 12 (GPIO 18) - Key Up
- Wire # 13 (GPIO 27) - Key Down
- Wire # 15 (GPIO 22) - Key A
- Wire # 16 (GPIO 23) - Key B
There is five buttons that is connected to the PCB near on the bottom of the display. The GPIO number for these buttons are listed below and on the PCB.
- GPIO 5 - Key Z
- GPIO 6 - ESC
- GPIO 12 - ENTER
- GPIO 13 - SPACE
- GPIO 16 - Key X
The four button version uses the same wiring from the Pi Cable, except two extra wires need to be connected to the Perma-proto PCB.
- Wire #3 (GPIO 2) - Key X
- Wire #5 (GPIO 3) - Key Y
The diagram above shows which buttons are connected to the perma-proto PCB. Ideally, I want to say you can customize and change it up, but then the buttons won't fit in the cutouts on the 3D printed enclosure - so if you wanna change this layout, you'll also have to update the CAD, so keep that in mind.
To make the wiring a bit easier, we're using a Pi ribbon cable (the 26-pin one). This cable as a nifty connector that fits perfectly on the GPIO breakout on the 2.4" PiTFT. We'll remove the connector from the other side and wire that up directly to the buttons on the Perma-Proto.