So i finally got around to finishing my open sprinkler 1.4u i ordered well over a year ago.
It was my first soldering and irrigation project so it took me a little while to get it all together. But lo and behold i finished it a couple nights ago.
I tested the voltages on the board and everything checked out. So i hooked up the lcd and found everything to be functioning properly, however the lcd was illegible due to insuficcient contrast of the displayed text.
the screen is bright but i can barely see the text. I have to angle it to be able to read it at all.
I admit the sloppiest soldering on the board is on connection of lcd to pin adaptor. After noticing this i went back and cleaned up the solder bridges on that interface and it still the same issue
I can post pictures if that will help.
im just curious if this problem has been seen before? could i have perhaps ruined my lcd w/ extended solder heat? is it just a defunct lcd?
either way thanks for any advice anyone can provide! i look forward to working with this as i now have a robust application. cheers!
Wow, 1.4 has been discontinued a long time ago and I have to remind myself how the contrast works on this version. If I recall correctly, 1.4 uses a resistor voltage divider to create the voltage that controls contrast. It’s possible that you may have soldered the wrong resistor — according to the instructions (http://rayshobby.net/opensprinkler/svc-build/opensprinkler-v1-4-build-instructions/) RLED is a 100 ohm resistor. Please confirm this is the case. If you soldered a different resistor to RLED, that will create the wrong voltage for contrast.