i'm playing with Waveshare e-paper with SPI interface. I modified Arduino Nano - changed LM1117-5.0V voltage regulator with LM1117-3.3V and shorted Nano's pin 5V(which is now 3.3V) with 3V3, removed USB voltage diode and hooked up USB voltage to LM1117-3.3V input. Now i have 3.3V Arduino Nano with CH340 chip also running on 3.3V. So far so good - simple sketches load up with no problem so communication vis usb with modified CH340 works.
My goal is to hook up 2.9 inch e-paper via SPI (4 wires) and SD card via the same SPI pins. I know that CS pins of SD card and display have to be on different Arduino's pins to be able to switch between modules. But let's leave SD card part now.
The main problem now is to communicate with e-paper display. I tried bunch of libraries i found on the web including EPD library from:
AFAIK EPD library won't work as it calls for led = 13 (which should be used as SPI's SCK?) and wake_up = 2 pin which is not present on 2.9inch display module! I found these pins are on 4.3inch (800*600pixels) display version but 4.3inch display do not use SPI but UART! I can't find working version for 2.9inch version.
I'm so confused:/