MicroMod Environmental - MicroMod functional module with environmental sensors

Description

Function module designed for MicroMod boards. It combines the SGP40 (air quality), SHTC3 (temperature and humidity) and STC31 (CO2 concentration) sensors. The module has an M.2 connector and works with MicroMod Main Board (Single) and MicroMod Main Board (Double).

The SGP40 uses a metal oxide (MOx) sensor with a microplate. Provides indoor air quality information based on volatile organic compound (VOC) concentration. Both the sensing element and the VOC algorithm are highly resistant to contaminating gases present in real world applications, allowing exceptional long-term stability as well as low drift and inter-device variability.

SHTC3 is a highly accurate digital humidity and temperature sensor. SHTC3 uses a capacitive sensor with a relative humidity measurement range from 0 to 100% RH and a temperature sensor with a measurement range from -40 ° C to 125 ° C. It offers a high accuracy of ± 2% RH and ± 0.2 ° C.

The STC31 measures CO2 concentration based on thermal conductivity and has two measuring ranges for CO2: 0 to 25 vol%; and 0 to 100 vol.% The repeatability of the measurement is 0.2% vol. With a stability of 0.025% vol / ° C. The accuracy of the measurement depends on the measuring range: 0.5% vol. + 3% of the measured value; 1 vol.% + 3% of the measured value. Utilizing measurements with SHTC3, the STC31 is able to provide measurements with moisture compensation along with temperature compensation.

The good performance of these three sensors is based on Sensirion's patented CMOSens® technology, which combines the sensor element, signal processing and digital calibration in a small CMOS chip. The sensors connect to the main module via the I2C interface. There is a 3.3 V voltage stabilizer and a power LED on the board. Full documentation with examples of use is available on the product page.

MicroMod is an interface ecosystem that connects the main module to the processor or the microcontroller to various peripherals through expansion boards. Using the M.2 standard, MicroMod allows easy replacement of main modules.

Features

• Input voltage range
  • 2.5V to 6.0V
    • Typ. 5V via Main Board's USB connector
    • Typ. ~3.7V to 4.2V via Main Board's LiPo battery Connector
• IO voltage
  • 3.3V
• AP2112 3.3V voltage regulator (rated 600mA)
• Power LED
• I2C pull-up resistors
• Sensirion SGP40 Air Quality Sensor
  • Uses I2C interface
    • Address: 0x59 (default)
  • Operating voltage range
    • 1.7V to 3.6V (Typ. 3.3V)
  • Operating temperature range
    • -20°C to +55°C
  • Typical current consumption
    • 2.6mA during continuous operation (at 3.3V)
    • 34µA when idle (heater off)
  • Output signal
    • Digital raw value (SRAW): 0 - 65535 ticks
    • Digital processed value (VOC Index): 0 - 500 VOC index points
  • Switch-on behavior
    • Time until reliably detecting VOC events: <60s
    • Time until specifications are met: <1h
  • Recommended sampling interval
    • VOC Index: 1s
    • SRAW: 0.5s - 10s (Typ. 1s)
• Sensirion SHTC3 Humidity and Temperature Sensor
  • Uses I2C interface
    • Address: 0x70 (default, non-configurable)
  • Operating voltage range
    • 1.62V - 3.6V (Typ. 3.3V)
  • Operating temperature range
    • -40°C to +125 °C
  • Relative Humidity
    • Measurement range: 0% to 100%
    • Typical accuracy: ±2 %RH
    • Resolution: 0.01 %RH
  • Temperature
    • Measurement range: -40°C to +125 °C
    • Typical accuracy: ±0.2 °C
    • Resolution: 0.01 °C
  • Typical current consumption (varies based on mode)
    • 4.9µA to 430µA (Normal Mode)
    • 0.5µA to 270µA (Low Power Mode)
  • Allows the STC31 to compensate for humidity and temperature
• Sensirion STC31 CO2 Sensor
  • Uses I2C interface
    • Addresses: 0x29 (default), 0x2A, 0x2B, 0x2C
  • Operating voltage range
    • 2.7V to 5.5V (Typ. 3.3V)
  • Operating temperature range
    • -20 °C to +85 °C
  • Calibrated for CO2 in N2 and CO2 in air
  • Measurement ranges
    • 0 to 25 vol% in N2
    • 0 to 100 vol% in air
  • Accuracy
    • 0.5 vol% + 3% measured value in N2
    • 1 vol% + 3% measured value in air
  • Concentration and temperature resolution: 16-bit
  • Repeatability: 0.2 vol%
  • Temperature stability: 0.025 vol% / °C
  • Start-up time: 14 ms
  • Thermal conductivity sensor provides calibrated gas concentration and temperature output
• Jumpers
  • PWR LED
  • I2C pull-up resistors
  • STC31 address selection