Ruuvi Tag Wireless 4-in-1 Humidity & Temperature Sensor

Know what's happening inside your van — even when you're not in it. The Ruuvi Tag is a Bluetooth sensor the size of a poker chip that broadcasts temperature, humidity, pressure, and motion data to your phone for years on a single coin cell.

Why van owners love it

• Monitor cabin temperature while your dog naps inside (or your espresso machine sits in the cabinet on a hot Moab day)
• Catch condensation problems before they become mold problems — humidity tracking right inside the wall cavities
• 5+ year battery life from a single CR2477 cell — true install-and-forget
• Bluetooth range up to 30 m (100 ft) line-of-sight; pair with the Ruuvi Gateway for cloud access from anywhere

Specifications

• Temperature range: −40 °C to +85 °C (−40 °F to +185 °F)
• Humidity, atmospheric pressure, and 3-axis accelerometer all in one unit
• IP67 dust and water rated
• Open data protocol — works with Home Assistant, Node-RED, Grafana, and Ruuvi Station

Drop one in the cabin, one in the fridge compartment, and one outside the van. Now you have a tiny weather station for your build.