The RuuviTag by the finnish startup Ruuvi is a small open source sensor.
This little device reads data like humidity, air pressure, motion and temperature.
Thanks to Bluetooth LE it’s very low energy consumting and runs with only one CR2477 battery 1-2 years.
The device is only 45mm in diameter (52mm with the waterproof housing) and with its wide operating range from -40°C to +85°C this piece of hardware can be used in almost every environment.
With MAM (masked authenticated messaging) you can stream your data straight to the IOTA Tangle.
Sell your data on a marketplace or use it for other purposes.
The RuuviTag was the first mass produced IOTA compatible device.
IOTA and Ruuvi partnered in 2017.
The Ruuvitag comes in a 1-pack or in a pack of 3.
Instructions on how to connect the RuuviTag to the IOTA Tangle using MAM can be found on: https://lab.ruuvi.com/iota/