Easter egg painter helping hand

Rotates the egg. Nothing more to it.

BOM
- printed parts
- M5 threaded rod and 8x M5 nuts
- M3x50 bolt and 1x M3 nut for egg holder
- 2x M3 nut and 2x M3x5 bolt
- a spring for the egg holder "idler"
- 28BYJ-48 stepper
- Arduino
- ULN2003 driver, easily found on eBay

Reused code from http://forum.arduino.cc/index.php?topic=85335.0 to drive the stepper at a constant (slow) speed. The code from the first post will work just fine, all you need to modify is the main loop().

void loop() {
   motorSpeed = 1;  // set a constant slow speed
   clockwise();          // start clockwise rotation
}

Connect the signal and power wires from the ULN2003 driver board as follows to the Arduino Uno:

IN1 to Arduino pin 8
IN2 to Arduino pin 9
IN3 to Arduino pin 10
IN4 to Arduino pin 11

5V+ to Arduino Uno 5V
5V- to Arduino Uno GND

It will work on a Micro or Nano as well, but you'll need an external 5V power supply for the stepper.

Happy painting :)