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A project log for Color Open Source Smartwatch

Reverse engineering the SMA-Q2 smartwatch to run open source firmware on it

emerythemeryth 10/16/2019 at 14:224 Comments

I have been very slowly working on the project.

I now have a very simple firmware (based on Nordic SDK and FreeRTOS) that showcases all the hardware in the watch, and basic integration with Gadgetbridge (smartphone app).

I'm working on publishing the source now.

Heart rate monitor
Heart rate monitor

The heart rate monitor outputs raw waveforms and it's up to the firmware to analyze them.

There is a binary library from Pixart for that, but because it requires 13kB of RAM I don't want to use it.

With simple filtering and FFT I've managed to get a pretty good result, compared to a chest strap sensor.

Unfortunately the slightest movement disturbs the PPG reading, so it may never be useful for fitness tracking.

The accelerometer has built-in tilt and tap detection that works great. It's interesting that the original firmware did not use them at all.

I haven't ported DOOM yet, but have a Tetris clone by my friend [msgctl]:

Discussions

Jeremy wrote 11/05/2019 at 02:25 point

Neat!

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morgan wrote 10/16/2019 at 21:55 point

This is great and super well timed! I just got one of these last week and keen to start hacking!

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arthur_jordan05 wrote 10/16/2019 at 17:59 point

Thumbs up! What a great job! Also, the design is quite beautiful

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de∫hipu wrote 10/16/2019 at 17:13 point

Thank you for the update! This is really exciting!

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