Some code I wrote while testing the Texas Instruments CC2650STK SensorTag.

Disclaimer: I'm running SensorTag firmware 1.32, it may not work with other versions.

util/tempconvert.c and util/humconvert.c are two small programs that convert the output you would get by manually reading the data characteristics of the temperature and humidity sensor using gatttool. They are used by passing the output like ./tempconvert.c e0 08 48 0c, where the output is in the format Object[0:7] Object[8:15] Ambience[0:7] Ambience[8:15].

util/readdata.py is a small Python script that connects to the SensorTag with the hardcoded MAC address and continuously displays the data from the temperature and humidity sensor.

This functionality consists of 3 parts.

server/logger.py connects to the SensorTag using the MAC address stored in server/mac.txt. This is such that the address is untracked by any VCS in case the device is often changed. So be sure to have the MAC address of your SensorTag in the file, otherwise it won't work. It then reads temperature and humidity data from the SensorTag in the hardcoded interval (default 1 minute), stores the latest data in latest.csv and appends it to history.csv.

It also has the option to send you a notification on Telegram, if you have a Telegram bot. To use this feature, create the file server/telegram.txt and have your bot's token on the first line, and your chat_id on the second line. Obtaining your id is a bit difficult, see this answer for more information. If you have set it up correctly, it will send you a message using the given bot after 20 connection retries have failed.

server/server.py listens for incoming GET requests on default port 8081. On receiving /latest, it returns the latest measurements from server/latest.csv encoded as JSON. On receiving /history, it returns all the historical data from server/history.csv.

Both the logger and server can be started by using server/start.sh, which creates a GNU screen session for each of them. This has the additional advantage of automatically attempting to reconnect to the SensorTag if the logger has exited due to losing the BLE connection. Please not that you'll obviously have to have GNU screen installed, as well as a working Bluetooth stack. As far as python modules go, you'll need to use pip to install web.py, pygatt and pexpect.

android/Weather is an Android app using the service provided by the server to get and display current and historical data. The IP and port of the server are stored in the untracked string value file creds.xml as the string R.string.IP in order not to show up in VCS.

This project uses the following libraries

• pygatt
• android-async-http
• MPAndroidChart
• Android AppCompat and Support Library

MIT license