Unicorn Hat HD + Raspberry Pi Pico W: possible?

Support
1

My dream is for Pimoroni to expand on what they did with the Pico Unicorn (16x7) and upgrade it to a 16x16. They sort of achieved this with the Stellar Unicorn, however it is too large for my application, and has too many unnecessary features.

Until Pimoroni makes a 16x16 Pico Unicorn, I am searching for other options: Is it possible to wire a raspberry pi pico W to a unicorn hat HD? Would the new Stellar Unicorn driver work on that display? And if so, how would the pico be wired to the UHat HD pinout?

2

I have created an adapter-pcb that mimics a pi: GitHub - bablokb/pcb-pico-pi-base: An Interface PCB to use Pi-Hats with a Pi-Pico(w). There are some commercially available similar adapters, but you have to be careful and check the pinout first.

That would solve the hardware-part. On software-side, you would have to port the python-driver from Linux-python to Micropython (or whatever you use). I did this for a number of hats (see the repo for the code and examples). This could certainly also be done for this hat, since it only uses SPI.

3

I’m a bit of a novice, so I’m hoping for a dead-simple pinout diagram to show exactly how a Raspberry Pi Pico W would be wired to a Unicorn Hat HD. I think there are only 4 inputs needed. Unicorn HAT HD at Raspberry Pi GPIO Pinout

4

Just look for a Pico-W pinout diagram and wire mosi to mosi, miso to miso and so on. For chip-select you can take about any pin. Note the Pico W is very flexible regarding these SPI-pins (MOSI, MISO SCLK), so you can choose the pins that are most suitable (i.e. make wiring as easy as possible).

Watch out for the naming, in the typical Pico-W pinout diagram you now usually have TX, RX, and SCK:

SPI-TX = MOSI, SPI-RX = MISO, SPI-SCK = SCLK.