Friday, December 4, 2015

Direct control of Pebble with Arduino

Slow week, and I was cleaning up the bench.  Stumbled on one of my Sparkfun Bluetooth Mates.
I used these with the metawatch a few years ago.  I was never able to work out the pairing to get these to connect to the Pebble.  Well, I know a bit more, and I'm probably even more persistent these days...

I need to work out how to send an application message, then I can go phoneless.  I might have to use the Wixel again, could keep my parts count down.  This will net me a larger carry, but no phone requirement for extended periods.  Still need to get calibrations in somewhere, though.

This guy (here) was close.  But he's leaving out the initial pairing step.  The packets have changed since this was published also.  Allot of strange details, probably bluetooth device dependent.  I'll post more when I can sort through all the details, but I can reliably pair with the watch and send a notification to it.


  1. How does the calibrations work? It sounds like you need a fast processor to do some intense calculations? Is there something, somewhere, that describes this process?

  2. No real processing issue, will do it on the phone though, since that's not static sensitive. Calibration at it's simplest is y=mx+b.
    b=30000, y is mg/dl value from your finger stick, and x is the isig value from the sensor. Get your slope. Once you have a few data points calculate you b (intercept) value also, although allot of the time you are better off with 30,000.

    Anyway push the slope/intercept values to the watch and feed it isig values from the phone or the device, and let it calculate your mg/dl.