Shahriar Shahramian Resurrects a Dead NordicTrack S15i Exercise Bike with an Adafruit Metro Mini 328
With a dead Android control tablet, this high-end exercise bike could have been heading for the tip — but now lives again.
Electrical engineer Shahriar Shahramian has brought a broken high-end exercise bike back from the dead — by building a brand new control board and corresponding software.
"The brain of the bike resides inside a custom Android table at the front console of the unit," Shahramian explains of the deceased NordicTrack S15i exercise bike, which is mechanically sound but whose electronics smarts have bit the dust. "[This] Android PC is completely non-responsive. It draws very little current and looks like its memory chip is either dead or corrupted. Without access to the programming tools and the software there is very little chance of actually fixing it. The software & hardware of the bike are not publicly available and a replacement unit costs upwards of $1,000."
The solution: ripping out the deceased tablet and building something simpler but functional, in the form of a custom control board which is able to interface with the bike and control its resistance level as well as monitor revolutions per minute (RPM) in order to calculate calories burned during exercise and the power output generated by the user's pedaling.
"All we want to do," Shahramian explains, "is to control a DC motor in order to set the resistance [and] we also want to control an LCD screen so we can display our statistics, and of course measure the RPM — so, in terms of modules, I'm going to use a Metro Mini [328], which is an Arduino-compatible module that you can buy from Adafruit, and then there is also an Adafruit 3.5" TFT display which you can directly control from the Metro Mini. I'm also going to use a DRV8871, this is a chip from Texas Instruments allowing you to control a DC motor in both directions."
With everything integrated into the bike and taking the place of the previously-installed but now-useless electronics, Shahramian's bike is once again operational — albeit with a few features, like guided exercises, audio playback, and simulated elevation adjustment disabled. "Although much simpler than the original hardware," he admits, "the new system is sufficient to use the bike and achieve a satisfactory exercise routine."
More information is available on Shahramian's YouTube channel.