I am using a UNO R3 with a SainSmart LCD Keypad Shield V1.0 and SainSmart 4 Relay module as a temperature controller to read 2 thermistors and run 2 pumps. The board is powered from a 10V 0.85A power supply, that also supplies power to a 5V regulator that powers the thermistors to be read by the analog in pins. See diagram. The LCD has a menu system for adjusting variables, and one option to display the current temperatures. Everything work fine until I hook up more than one of that analog inputs. When I do the lcd display will not enter the temperature display screen, it just stays in the menu. Everything functions fine, but I really want to be able to display the temps. Any help would be much appreciated.
Temp_Cont_Software.ino (10.9 KB)