I have a unicorn hat and a Raspberry Pi 3. In my project I want to use both the unicorn hat and a PIR sensor.
I also want my unicorn hat auto detected using the hat EEPROM.
If I plug it direct into the Raspberry Pi 3 it runs perfectly
I have worked (from https://pinout.xyz/pinout/unicorn_hat) out that to get the hat working and not autodetected I need to connect the following pins:
Pin 2 (5v Power)
Pin 9 (Ground)
Pin 12 (BCM 18) data
However in this mode the hat runs with only half the lights blinking.
I want it to autodetect so I don’t want to change the
I assume if I connect all the pins it will do what I need since it works when plugged in directly but I want to work out which pins are used.
I have tried connecting the following:
Pin 27 (BCM 0) ID_SD)
Pin 28 (BCM 1) ID_SC)
This didn’t work.
Pin 1 (3v3 power)
in case the eeprom chip used this but same result.
In this case sometimes when I turn on the raspberry pi 3 random unicorn hat lights come up lit
I then realised there was a second 3v pin so I tried connecting:
Pin 17 (3v3 power)
Again no result (Although the unicorn hat lights haven’t started in the lit state so something may be different)
I realise the gnd pins are all connected to each other so no point trying them.
I have googled for a data sheet for the unicorn hat or some other kind of documentation which could help but no avail.
Can anyone tell me which pins are required, or am I down to trail and error and connecting them all and unconnected them one at a time until I work out which one.