Custom Footprints

Published on 2017-04-15 in D1 Mini Matrix Deluxe Shields.

I made the trip to the hackerspace and used their hot air gun, and desoldered/resoldered the chip properly. I can now confirm that the resistors that I removed from the example schematic in the datasheet when designing that version of the PCB were in fact necessary for the chip to function. Who would have thought! Oh well, I just need to wait for the other version of the PCB, with all the resistors, to arrive.

In other news, I also received the PCB for the 7x11 matrix and the IS31FL3736 chip. Unfortunately, there is a small problem with the QFN footprint that I used (instead of making a custom one based on the datasheet):

Turns out that just taking a 36-pin QFN footprint and adding the pins to make it a 40-pin QFN footprint is not enough – you also have to scale it down. I have now corrected all my QFN footprints for those chips to be exactly like in the datasheets, and re-did the PCBs. Of course it’s another couple of weeks until they arrive…

\