Star-Cycle

Description

Star-cycle lets you cycle through a star-field. In addition to a three dimensional star-field, the Raspi displays some information regarding your performance is displayed: The speed, the distance, an estimation for the energy used, the current date and time (in a somewhat strange stare-date format) and the time you are cycling.
The program is written in Java, using the BlueJ-environment provided on the Raspberry Pi. It was developed on (and for) model 2B, but since one of its cores is more than sufficient even using high display resolution, it probably also will run on the older models.
Only very limited hardware skills are needed and it should be possible to use nearly every exercise-bike model.

Details

Hardware

The sole signal needed by star-cycle is a pulse on one of the Raspi's IO-ports on every revolution of the pedal levers. My exercise bike has a tachometer generator, consisting of one reed-switch that is closed once per revolution. Normally, this switch is connected to the exercise-bike’s board-computer (via a mini TS-plug). For use with star-cycle, it is connected to the 3.3V pin and GPIO 7 on the Raspi's pin-head.

If your exercise-bike doesn't provide such a switch (or you don't want to modify it's circuits), it should be easy to add an external switch to the exercise bike: Simply glue a reed-switch somewhere near one pedal lever and stick a magnet to the lever so that the lever closes the switch once every revolution. The switch is then connected to the 3.3V signal and the GPIO 7 signal on the pin-head.

WARNING: Do not connect your exercise-bike’s circuitry directly to the Raspi unless you know exactly what you are doing, since both devices can be damaged that way.

Software

The software is provided as a BlueJ project. The BlueJ-development environment, including the library necessary for using the Raspi's GPIO pins (namely pi4j), is already installed on recent Raspian versions.

Files