I’ve been playing around with all kinds of fitness trackers that I have and realised they’re mostly IMUs and the work is done in the software, likely on the phone. With this in mind I decided to buy an IMU dev board and make my own fitness tracker.
My goal is to reproduce the capabilities of MOOV Now which offers live coaching for cycling, in the form of cadence tracking, but also passive sleep tracking.
My IMU arrived yesterday so today I’ve been playing with the SparkFun 9DoF Razor IMU M0 and getting it to do some basic data recording. It does two things out of the box: log data to a microSD card and output the same data over serial. It takes a few commands over serial as well, mostly to turn off features.
I’ve set up my environment to write new firmware but at the moment I want to play with existing data, so I’ll be capturing some IMU data tonight, on my way home, and hopefully compare it with what I get from MOOV. I’ll make some pretty graphs that won’t mean anything but will look amazing!
Final initial goal is to publish cadence metrics periodically and come up with a training program. It might involve hooking it up to a Bluetooth transponder so I can write an app which feeds back on how well I’m maintaining optimal cadence.
The secondary goal is to see if I can extract sleeping data out of the sensor since I’m never happy with the black box that some of the fitness trackers are.
For sleeping it will be interesting to see the difference in results when putting the sensor on different limbs.
I might need to print out a case to make it more resilient so if anyone wants to learn 3D printing this is a good practical project that I’m willing to coach people.
P.S. If anyone can hold my hands through learning DSP I will buy you a drink!