I try to make a thermostat for our sauna. Im using a lm35c with a arduino mega and a http shield so i can read the temp from a distance. There is also a lcd display and 2 buttons to set the temp.
Everything is working great but when i disconect the usb cable to the pc the program is starting behaving stranges.
It didnt stop warming after the set temp is crossed. When i put the usb back in the pc everything is working again.
I use a power supply from 5V to feed the arduino mega via the powerjack.
Is this a power issue? Please help.
Thanks in advance.
For the software look at the attachement.
thermostat.txt (6.69 KB)