PMOD LCD Backlight PWM pin

[De Bug]

Some SPI LCDs have a PWM Backlight On/OFF/PWM  input.  I want to create a PMOD compatible LCD board.

Which  pin should be most applicable to assign as PWM on a RGB LCD PMOD  connector ? Pin 9 VCCEN or P10 PMODEN ? Reference modules: PMOD MTDS, PMODOled

 

 

 

 

Edited March 29, 2023 by Debug

[JColvin]

Hi @Debug,

If I had to choose, I would use Pmod Interface Type 2A as explained in the Pmod Interface Specification available here: https://digilent.com/reference/pmod/start. This allows for four other GPIO pins beyond the four standard SPI pins. As for which of those four pins to choose from, I suppose I would choose either pin 9 or pin 10 in case the device was ever going to be daisy chained for some reason (since SPI doesn't really support strict "daisy-chaining" as much as parallel connections) to better be in alignment / avoid conflicting with the alternate pin recommendations for pin 7 and pin 8.

Thanks,
JColvin

[De Bug]

Thank you. I went for pin 9 using 2A. P9 is defined as VCCEN for LCD SPI , which is  a kind of power enabling, which seems most applicable for the backlight power.