Revive your fitness bike by adding real world road trips: pedal in front of your TV or monitor, and promenade on the roads faster or slower according to your cycling speed. No need for any trainer or app, you just need a fitness bike, a raspberry pi (any model), and a homemade cadence sensor (shown below)
The idea behind this solution is quite simple: play a video file in VLC and control the frame rate (FPS) according to the speed we get from the pedal. In this matter, we build a cadence sensor, and attach it to one of the pedals. The sensor then sends the pulses on one GPIO input pin of Raspberry Pi, and then, based on the periods we receive these pulses, we compute some speed. Finally, based on the value of the speed, we control VLC frame-rate
Fortunatelly, to control video playing in VLC is quite simple, we just need to start its embedded telnet server, to which we send commands from the client script.
- A fitness bike (I suppose you already have it)
- A Raspberry Pi, any model above 2 (VLC should play smoothly on it)
- A magnetic sensor (for example PS-3150 or KY-021 but honestly any other cheap magnetic sensor should work)
- Neodymium magnets (1 or 2 pieces), an example here
- The scripts in this repository, which you need to copy on Raspberry
- A video file recording of your favourite road trip
vlc-server.sh -> starts the VLC's telnet server, which will be used to receive commands by the client script
vlc-client.py -> starts the client script, which is doing everything we need: connects to VLC telnet server and sends framerate commands based on values it reads from our cadence sensor
start.sh -> the main script, which first starts the VLC server then the client script. This is the script you need to run. But before, you need to edit it and change the video file name and the seek value (the seconds you want to skip from the beginning of the file)
The cadence sensor is a very important component, as it's attached to the pedal and "reads" the number of pedal rotations per minute. It's composed of a magnetic sensor (attached to bike's shell) and a neodymium magnet (attached to the pedal).
For the magnetic sensor I use a door sensor PS-3150, but you can use anything else, like the cheap KY-021
I'm using GPIO pin 13, which I set it as input pin. A cadence sensor is linked to this pin and VCC 3.3V pin
Attaching the sensor to the pedal is easy, use a double adhesive tape for the sensor itself, to stick it to the bike shell. Then just stick the neodymium magnets to the pedal, making sure the distance when crossing in front of the sensor is around 10 millimeters
The two wires coming out from the sensor can be connected to Raspberry Pi without taking in account any polarity, as the magnetic sensor internally is just a switch.