AquaticTechTank.net

So what's your wiring look like?

The schematic made by O2surplus is different since he used a HJ1602A LCD which is different from your LCD.

Well, I wired as it was the part that you have listed on the first page of this thread.
I have some jump wires so I can do some changes outside of PCB (in the air just to see if it works) and then will order correct model number.

So panorama sent me his board and LCD. I soldered it up and everything is working. Maybe check for shorts.

PANORAMA LOL

Well, I go the bootloader on the ATmega, had some issues with that
Back to applying mistergreen's code ... will be back soon with updates

What would need to be done to make this code work with an Arduino Mega 2560 and a ITDB02 or Nextion TFT screen?

I'm wanting to building my own LED lighting controller and I think having a PAR meter built in would be a great feature. This way it could display the PAR value during the different light cycles like sunrise/sunset etc. or possibly even allow adjustment of lighting levels to a specific PAR value.