migration from 16F876a to 18F25k22

[Demon]

I have 100R and 1K pots on my circuit; backlight and contrast (can't say which has which pot by looking at it).


Look at the Electronic Parameters at bottom left:
Voltage Logic 5V typ.
Voltage LCD 20V typ.

The LCD has a range of 4.5 to 30 volts, 5 volts should work, and I'd stay away from the upper max. I'd start with an old PC power supply (5V and 12V) and give that a shot if you don't have a variable power supply, or a bunch of old wall adapters.

So yeah, I'd go with 500R pot on LEDA and 10K pot on V0 to start, and then tweak until I hit a pot that has an acceptable range. You'll see a sweet spot when you get to the right one; from dark to not "too" bright. Brighter LEDs mean shorter life, I aim for the just-enough-for-me range.


I also noticed something else on your datasheet; CONTROLLER: RA8835 OR EQUAL. I'd do some googling on RA8835 and see if more examples come up. You can never have too many schematics, tables or descriptions.

Robert