- on Education & Information
- Published in issue 9/2011 on page 22
I2C Sensors
For atmospheric pressure, temperature and humidity

Most sensors are inherently analogue and in general it is necessary to amplify, compensate and calibrate their outputs before digitising them. The sensor modules described here have everything built in: a microcontroller connected to the module can fetch the calibration data needed to correct the digitised results over the I2C bus, meaning that no calibration is necessary.
- Pressure measurement range: 300 hPa to 1100 hPa
- Temperature measurement range: –40 °C to +
- Supply voltage: 2.2 V to 3.6 V (3 V typical)
- Current consumption: 1 ?A (standby), 500 ?A (during measurement)
- Operating temperature: –40 °C to +
- I²C interface SCL maximum frequency: 500 kHz
- MCLK frequency: 30 kHz to 35 kHz (32.768 kHz typical)