More details!
Saw the reference to a log file, here it is:
====== Fri May 8 10:44:12 2015 ======
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x1e960a
avrdude: Expected signature for ATMEGA644 is 1E 96 09
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file “./Firmwares/OpenSprinkler_v2.2/firmware2.1.4.hex”
avrdude: input file ./Firmwares/OpenSprinkler_v2.2/firmware2.1.4.hex auto detected as invalid format
avrdude: invalid input file format: -1
avrdude: write to file ‘./Firmwares/OpenSprinkler_v2.2/firmware2.1.4.hex’ failed
avrdude done. Thank you.
====== Fri May 8 10:44:12 2015 ======
Error uploading firmware.
Since it was giving “invalid file format” for 2.1.4 I tried uploading 2.1.3 and it worked! So, doesn’t look like there’s any kind of power/assembly issue at this point, more of a software issue. Assuming no further issues someone might want to move this to the firmware forum.