Connecting to Unicorn HAT HD without using 40-pin header


#1

Hi,

I wanted to remove the header from the Unicorn HAT HD, to reduce the space it occupies and to allow access to the Raspberry Pi GPIO pins.

Are the small gold squares on the back and to the side of the HAT solderable? Can I connect to the HAT using those? If so, what square corresponds to what input?

I noticed the normal Unicorn HAT has three breakout contacts on the side corresponding to VCC DIN and GND. I was hoping the gold squares on the back of the Unicorn HAT HD are like that, I am confused since there are 8 squares but I would only need 6 (4 data inputs plus a 5v connection and ground) if I am not mistaken.

Thanks a lot for any help!

Victor.


#2

Hi!

Those pads are just for flashing the onboard MCU and testing the HAT, there’s no SPI data connections there. You’d have to use the HAT header pads for data input. Remember to be careful when removing the header, there’s a lot of traces running on the PCB under the header.

Also, the pads on the Unicorn HAT are for data output from the HAT, they enable one to connect for example extra Neopixels to be driven from the Pi.


#3

Thank you! that is very helpful and answers my question.


#4

Does this help? Unicorn HAT HD Pinout