Nice one! I rebuild it made some minor modifications. I built the motor controllers on an Arduino test shield, used the same ULN2003 (2pcs.) have a few of this circuit since I repaired slot-machines. (The ULN2803A circuit would be nicer, it has 8 input and outputs just enough for the two motors. )The 28BYJ-48 steppers voltage is 5V. 12V is too much for them, so they heat up. I lowered the voltage to 5V. (no overheating) The current consumption of the circuit at 5V is around 200mA maximum, so it works from a USB port, no extra power adapter needed. Thank you!
Universal Timer - Sprinkler...View Instructable »