Originally Posted by zodduska
I was looking into dimming it, I think you can use a PWM pin and some code to do it but I'm not sure how. I'm personally adding a resistor to the default hookup tonight to reign in the brightness a little.
Edit: I put a 1k ohm resistor between the backlight 5v, red wire—second from the right in my pic, it's no longer annoyingly bright. Use a higher value resistor if you want it even dimmer.
Thanks Zodduska, I also tried a few resistors found found one that gave a pleasing brightness.
Also I worked out a way to turn it on and off with alarms: I used Pin 13 as the power source for the backlight, and controlled it like this (with new "cases" for testing):
// ... later ...
pinMode(13, OUTPUT); //DJT 11/25/13 for LCD screen power on and power off
LCDPowerOn(); //DJT 11/25/13 Turn on LCD when program initializes
//... later ... end of day alarms
//... later ... cases for testing
case 33: //DJT
case 34: //DJT
// ... later ... the functions:
void LCDPowerOn() //DJT
void LCDPowerOff() //DJT
This works so far - now my fish won't stay up all night watching the LCD!