Have anyone verified that the "Set Contrast Current (81h)" command works?
No matter what I set it to (1-127), there is no change in brightness. I've been trying things like long delays before and after the command, with no luck. Here is part of the code:
display_command(0x81); //Contrast setting
display_command(0x01); //1 to 0x7F
display_command(0x84); //Quarter range current
display_command(0xA8); //Multiplex ratio
display_command(0x3F); //All visible rows
Any thoughts on why it doesn't work?
The device is a RiTdisplay P19401. I'm using the SPI interface.