Description
My setup includes a Airlift breakout board, Eink 1.54 monochrome display board, and Metro M4 Express. When I connected the standard SPI lines to both the display board and the Airlift board, the Airlift board could not obtain a WIFI connection. So I created separate SPI lines for the display board. Once I had done that, the Airlift board worked as expected. You would think the problem was with the Airlift board, but no. The EPD software was keeping the SRAM CS signal low, which cause interference with Airlift SPI signals. I made a code change which I am happy to release. In adafruit_epd.py display() method, the self.sram.cs_pin.value is set to false but is not set to True with a monochrome display. The fix in is a if block at lines 136-154. _buffer2_size is 0 for monochrome boards, therefore self.sram.cs_pin.value is never set to True and stay False. Not good. I added an else: block after 154
else: if self.sram: self.sram.cs_pin.value = True
The seems to fix the SPI line sharing AND the issue #21.