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I'm trying to write a sketch to use a Wemos D1 mini connected to several shields including a LOLIN TFT & I2C Connector Shield (v1.1.0). This powers a small ePaper display (LOLIN 2.13" diagonal ePaper/eInk display) with a TFT e-Paper Cable.

The problem I'm running into is that I can't get the board to either boot properly or get out of deepSleep due to the pin assignment of the TFT display.

I have placed the following code before the void setup() as described in the manufacturer's GitHub example for the board:

/*D1 Mini*/
#define EPD_CS D0
#define EPD_DC D8
#define EPD_RST -1  // can set to -1 and share with microcontroller Reset!
#define EPD_BUSY -1 // can set to -1 to not use a pin (will wait a fixed delay)

By doing this, however, it results in the board entering a boot loop when I try to connect D0 --> RST

If I leave the D0 --> RST disconnected, the board will successfully run the sketch and enter into deepSleep but will not be able to Wake Up after a predetermined amount of time (10seconds).
I see the Builtin LED flash after 10seconds and there is some activity on the serial monitor so I suspect that the board is trying to wake up however it is unable to with the D0 disconnected to the reset pin.

If I try to connect the D0 --> RST after the board has gone to deepSleep and before the timer ends, it continues to sleep until the 10 seconds is completed, then starts its boot loop again with the Built-In LED flashing constantly.

Has anyone else had success in this? I suspect I'm missing something very simple but cannot find much info on this shield anywhere.

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  • you can use any pin as CS, it doesn't need to be D0. some pins on esp8266 have constraints electronics.stackexchange.com/questions/402066/… – Juraj Apr 6 '20 at 14:55
  • Thanks for your reply, Juraj. I have the sketch successfully running now using your suggestion and remapping the CS to another pin. However, unless I'm doing it incorrectly, this means I have to connect each pin individually between the D1 mini and the display using jumper cables without being able to use the TFT e-Paper Cable. So now I am wondering if it is possible to remap the pin outputs so I can still use the ePaper cable with one connection between the board and display? – Travis Hayes Apr 6 '20 at 18:09
  • I would remove the CS wire from the connector on the shield end and extend it with with a jumper wire – Juraj Apr 6 '20 at 19:03

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