Is the Angel Sensor M1 the device I need? 2016-07-07
BiodataHackingMicrocontrollers
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Recently I posted about my first results tinkering with the Angel Sensor M1 I bought. I was pretty happy to get it working to the point that I could read the sensors, but to be honest, I’m not sure this device is really what I was hoping it would be. The step counts seem to only register when I am running, not when I walk normally, so I get far fewer steps counted compared with the Withings Pulse I have been using up until this point. And I don’t think the device stores a history of when those steps occurred, so if I skip syncing one day, I don’t really know whether those steps happened yesterday or today. I also don’t know at what time they happened. For example, how many steps on that run at 15.00 vs steps counted when I was walking around the mall on the way to dinner at 18:00?)

But my main complaint is that it doesn’t have a simple display to see how many steps I’ve done over the course of the day. In order to check, I have to pull out my phone (or whatever device I install an app to read it), then pull out the Angel Sensor and press the button to enable the Bluetooth, then go back to the phone and read the number of steps. This really seems overly complicated if I just want to take a quick look to see how I’m doing today on my step count.

So the question running through my head is: how hard would it be to connect up an ATmega microcontroller to a motion sensor, battery and small LED display and some kind of wireless to sync with my phone? Coding the phone Bluetooth sync seems like the hard part, so if I can have it auto sync to some simple Raspberry Pi server in my home over any simple wireless system I want whenever I am home, then the RPi can upload the data to the net. Then I can have a simple Python app on the phone to view the data. 
The wireless I’m looking to play with is the Atmel ATA8510/8515. These look like they are a very simple to use UART to wireless transceiver device for things like wireless sensor networks. They only use about 10-20ma in TX and RX modes, and about 50-100uA in power saving IDLE mode. (It goes down to <1uA in “off” mode, but that makes it a little harder to wake up every once in a while to poll if anyone is waiting to talk to it.) And the price on Digikey is about $4.60 per unit which is well within my budget. (If I can figure out how to solder these onto a PCB since they use a QFN32 packaging.)
At the moment, this seems like more work than it is worth, but I will probably be exploring the Atmel ATA8515 wireless device for things like parking gate openers and sensor communications, so maybe I’ll swing back to this.