[Mikhail] sent us a teaser video for a hack he’d done (embedded below). He takes a Bluetooth LE fitness tracker dongle and reflashes it spit out the raw accelerometer data and trigger events. He then wrote a phone app that receives the data and uses the device as an alarm, an on/off switch, a data-logging device, and more.
We thought it was cool enough that we asked [Mikhail] for more detail, and he delivered in spades! Inside the device is a Nordic NRF51822, their ARM Cortex + Bluetooth chip, an accelerometer, and a bunch of LEDs. [Mikhail] mapped out the programming headers, erased the old flash, and re-filled it with his own code. He even added over-the-air DFU re-flashing capability so that he wouldn’t have to open up the case again.
The cellphone side of the equation is equally important, and equally impressive. [Mikhail] used Cordova to make a cross-platform browser-based mobile app that talks with the BLE device. If you’re thinking of doing anything similar, this is a great springboard to get started.
In the end, [Mikhail]’ fitness tracker does a lot more than the original developers intended, and the project has a professional level of attention to detail. Amazing. Even without that level of detail, with this hack you’ve got an inexpensive NRF51822 development platform, should you be interested in fooling around with Bluetooth devices.
17 thoughts on “Custom Firmware Unlocks Fitness Tracker”
Oh, that was the article I wanted to send to the Tip Line! Very nice application, certainly worth repeating.
Was this the device that was hacked? https://www.amazon.com/Misfit-Wearables-Activity-Tracker-Button/dp/B011HT9AEY/ref=sr_1_5?srs=8292283011&ie=UTF8&qid=1467564075&sr=8-5
Better start buying these before they figure us out and jack up the price.
I saw about 16 of these things at the used store for about $2 for a bag of 8.
They didnt know what they were. I was going to get them but the line ups were to long.
Now I kick my self in the but big time……
Well, not quite the same, but I got two of them for $8 each at Goodwill a few weeks ago. New in box though, was thinking of selling them, but it seems they’re much more useful.
seems like a nice little tracker for vr interfaces
Nope.. latency is too high
Mikhail this is great. Please contact me on my junk mail account email@example.com we have a product that we want to use something like this.
Awesome! If anyone wants a GCC friendly version/example for this board, check out this repo: https://github.com/averylouie/flashware
Came here to point out that you probably deserve some credit on this one. I’ve been keeping an eye out for these or similar cheap nrf51 based gadgets as a tiny devkit.
Awesome, this Bluetooth LE fitness tracker is the one I need!
Very interesting. Thanks!
does anyone have a link to the firmware and app code.
is it this one: https://github.com/averylouie/flashware
It doesn’t have a read me file so am a bit lost
most of the links on this page are broken anyone have links to app source. If the original creator of the code see this I could send a $20 paypal as a thank you.
apparently he moved there : https://mshtools.wordpress.com/
Can you do something similar with the misfit ray?
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