Pro-Mini CLone

I bought a Pro-Mini clone because I wanted low power (3.3v 8MHz) and a nice bolt-on PCB:

This board uses a USB-FTDI adapter. As want to use the E-Paper display and rationalise the wiring, I modified  epdif.h and epdif.ccp to repurpose MISO (as it is unused):

•  BUSY D8 (INPUT)
•  RST  D12 (OUTPUT) (was MISO)
•  DC   D9 (OUTPUT)
•  CS   D10 (OUTPUT)
•  DIN  D11 (MOSI) 
•  CLK  D13 (SCLK)

To do this I moved the pinMode definitions (in epdif.cpp) to after:

• SPI.begin();

and remapped the #defines in epdif.h to:

• #define BUSY_PIN      8
• #define RST_PIN        12

Although the E-Paper module sees 4.75 volts while the USB-FTDI adapter is connected, in normal operation it will see 3.3 volts. It is a shame the FDTI voltage out is 5v even with the 3.3v switch selection. Checking the WaveShare website this seems to be okay short term. Here is my hookup:

So I have D0-7 and A0-7 free and all ready for low-power battery operation.

Magic