Waveshare epaper 2.9 inch

Other Hardware General Electronics
1

Hi
Waveshare epaper 2.9" working fine @ 12 inch wire but I get garbled display with any length of wire longer than 12". I need to get to 12 ft.
Do I need to use resistors? What value? I tried with 1K at 3 ft length of wire but display was garbled. Can anyone help.
Thanks
Adil / Chandra

2

I had to look this up as SPI protocol has no precise standard. Old Motorola communications suggest up-to 3 Meters (10') but Wikipedia puts it like this:

  • No error-checking protocol is defined
  • Without a formal standard, validating conformance is not possible
  • Only handles short distances compared to RS-232, RS-485, or CAN-bus. (Its distance can be extended with the use of transceivers like RS-422.)

Further, there are SPI "extender" methods without resorting to RS-422. SPI extender at DuckDuckGo

But, I suggest for ease of project construction that you find a way to minimize the SPI cable... maybe mount the Arduino over/above the display.

3

The cable used will have an effect as will how it is used .
Worth a google - twisted pair telephone cable or cat 5 might be the way to go .

You could always have an Arduino at both ends and slow coms over UART might do it ??