The aim of the project is to build an interface between the user interface controller and resistance mechanism on a stair-step exercise machine. This M16C/62P microcontroller-based system gives you control over the resistance level instead of having to use one of the machine’s preset resistance levels.
The project will determine what the original system was trying to do, and adapt it into a usable output. The DC motor and mechanical wiper are replaced with an Analog MUX and a Futaba RC Servo. The 8 fixed resistance levels are replaced with a PID loop which attempts to achieve 8 RPM levels. This way, heavier and lighter riders will be stepping at the same rate for any of the 8 levels.
Stair Stepper Control
Project Firmware, Schematic and Documentation