According to the user guide https://s3-us-west-2.amazonaws.com/starterkit-assets/ATT+Cellular+IoT+Starter+Kit+Hardware+User+Guide+v01.pdf https://s3-us-west-2.

According to the user guide https://s3-us-west-2.amazonaws.com/starterkit-assets/ATT+Cellular+IoT+Starter+Kit+Hardware+User+Guide+v01.pdf https://s3-us-west-2.amazonaws.com/starterkit-assets/ATT+Cel... The sensor is an ST HTS221 capacitive humidity sensor. http://www.st.com/en/mems-and-sensors/hts221.html http://www.st.com/en/mems-and-sensors/hts221.html Honestly, this is just a development kit that AT&T contracted Avnet to design just to get developers using a cellular modem over AT&T's network. The development system (from Freescale and Avnet) and transport (Microsoft Azure, which is plenty secure) is unimportant.