SensorTag 2.0

Use this code at your own risk.

A simple python wrapper around BlueZ/GATTTool to talk to a TI SensorTag v2.0.

Prerequisites

To use this, first make sure that you have the appropriate software installed. I use bluez version 4.101-0ubuntu13.1 on my Ubuntu 14.04 laptop.

Of course, you will need some bluetooth LE capable hardware too. I got a Bluetooth Adapter by Medialink from Amazon that is capable of talking to this. To check if your existing hardware supports LE: Use hcitool dev to see a list of bluetooth devices. You will see your devices as hci0, hci0, and so on (in case you have multiple bluetooth devices. Replace hci0 with whatever you want to use from now on.

Executing hciconfig -a hci0 features should list <LE support>. If not, get a bluetooth USB dongle that supports LE.

Next, find the bluetooth address of your SensorTag by using hcitool -i hci0 lescan. It should be listed as a CC2650 SensorTag. This is the bluetooth address you will use for everything.

Usage

The sensortag library provides following sensors:

"temperature", "humidity", "barometer", "imu", "optical"

To use it in your code, initialize an instance with the bluetooth address:

example: tag = SensorTag("AA:BB:CC:AA:BB:CC")

Then enable the desired sensors:

tag.enable("temperature")
tag.enable("humidity")
    ...

Then call start with a callback function. The callback function receives a tuple t for every new notification from device, with

t[0] = name of the sensor
t[1] = processed sensor reading
t[2] = raw sensor reading as returned by the sensortag

A simple example to just print the data is as follows

def callback(t):
    print t

tag.start(callback)

Example

To see a sample, execute python sensortag.py <bluetooth-address>.

TODO:

For now, this library only works in the notification mode, with default sampling periods. Also, various sensor values are hard-coded. It'd be nicer to do service discovery using UUID's.