Characterising A Potentiometer With A Stepper Motor. 16 Comments ... current source feeds the pot while an Arduino with a motor controller turns ... the human ear in for example a volume control.

In this case, they’re being used to create a basic PWM motor controller. The trick is to set the 555 up in astable mode, and use diodes and a potentiometer in the charge/discharge loop.

Seeing this Toshiba motor drive, my first thought was ‘what a neat chip for pairing with an Arduino’ as it combines operation across 1.8 to 7V with up to 4A drive – so that is Li-ion batteries, 5V USB ...