CO2 meter

• Introduction
• Pinout and ports
• Hardware specifications
• Available sketches
• Links

Introduction

CO2-meter is a battery-powered carrier board designed to host a panStamp, a CoZIR CO2 sensor and a SI7021 Temperature+Humidity sensor. The whole can be used as a wireless air quality sensor for indoor spaces, where monitoring the CO2 level is necessary.

Pinout and ports

CO2-meter has two pin rows: one (P1) is used to program the on-board panStamp and the other (P2) provides some input-output pins to expand the board with more functionality.

The current version of the board provides no way to disconnect Rx (UART) from the CO2 sensor. This means that the CO2 sensor can not be attached to the board at the moment of programming a new firmware into the panStamp module. This is solved however by attaching the sensor to the board with a female connector and unplugging the sensor before flashing a new program.

Hardware specifications

• Size: 2.9 x 3.7 in (75 x 95 mm)
• Pin spacing: 0.1 in (2.54 mm)
• Current consumption: Less than 5 uA in sleep mode. 40 mA in active mode.
• On-board sensors:
  • SI7021 I2C humidity/temperature sensor
    • ± 3% RH (max), 0–80% RH
    • ±0.4 °C (max), –10 to 85 °C
    • 150 μA active current
  • CoZIR CO2 sensor
    • 0-2000 ppm detection range
    • ±50 ppm accuracy
    • 33 mA peak current
• Input voltage (Vcc): 2.0 to 3.6 VDC

Available sketches

CO2-meter works out-of-the-box with the co2meter sketch

This application sends CO2 level, temperature and humidity values periodically, based on the value of Tx Interval.

Links

• Schematics in PDF format