BMP180 Barometric Altimeter

Measure your floor's elevation to the metre with a $3 pressure sensor and an ESP32.

Difficulty: Breadboard. Estimated build time: about 60 minutes. Estimated parts cost: about US$8.50. 6-part bill of materials with live supplier pricing. A self-contained barometric altimeter that reads atmospheric pressure with millibar resolution and prints the result as both pressure (hPa) and altitude (metres above sea level) on a small OLED screen.