Pololu PTZ Controller
I needed a cheap controller for a Pan Tilt Zoom camera so I chose a Pololu Mini Maestro 24 Servo controller.
I programmed it to convert inputs to Pelco-D protocol and drive an LCD display.
Modded Honey Bee King
I could just about fly this awesome machine, but the main reason for buying it was to see how it all worked.
I still have it, having crashed and re-built it several times.
One mod was to use the downwash to cool the speed controller.
Before Microprocessors I used to design logic circuits to control outputs from inputs.
This is one of my circuits that controlled timed motor position and controlled its direction, activated by a switch.
PWM to Trailer Socket
I bought a 12N trailer socket and some 7-core cable only to find the car uses Pulse Width Modulation to control the brake lights.
So I made a simple relay box to detect PWM and control separate relays.