- Supports up to three panel chains for newer plus models and Raspberry Pi 2 that have 40 GPIO pins.
- Uses HCT245 to level shift signals from 3.3V to 5V and shield the Raspberry Pi GPIOs from overloading.
- Open source KiCAD PCB EDA format.
- Optional: Pads to power the Pi with 5V, including optional capacitor footprints (use something like 22uF-100uF; might be useful to smooth noisy power supply in particular if you operate the panels from the same supply. I use a 22uF/6.3V ceramic capacitor).
- Connector for RxD input (literally the only GPIO pin left) in case you want to make your panel controlled with a serial interface (3.3V logic level).
- (not very pretty layout, was just lazy and let the auto-router generate the first pass)
- BOM:
- 4x 74HCT245 or 74AHCT245 in 20-SOIC, 7.5mm package which should make it easy to hand-solder.
- 4x 100nF ceramic capacitor (0805 package)
- 1x 10kOhm resistor (0805 package)
- 3x 16pin IDC (=2x8) male receptible to connect the panels.
- 1x 40pin female connector to connect to the RPi.
- 1x (optional) 22uF .. 100uF capacitor for 5V rail.
- The Gerber FAB files are provided as active3-rpi-hub75-adapter-fab.zip
The board is also shared on OSH Park (not affiliated).
