Unit CO2

SKU:U103

◀

▶

Description

UNIT CO2 is a photoacoustic Carbon Dioxide (CO2) Unit that will tell you the CO2 PPM (parts-per-million) composition of ambient air. With a built-in Sensirion SCD40 sensor, power by Buck converter circuitry, and I2C communication. It has a range of 400~2000 ppm with an accuracy of ±(50 ppm + 5% of reading). What's more, it supports with temperature and humidity measurement too. Perfect for environmental sensing, scientific experiments, air quality and ventilation studies, and more.

Features

• CO2 concentration detection
• Temperature and humidity measurement
• I2C communication (Add: 0x62)
• Integrated 5V -> 3.3V Buck converter
• 2x Brick holes
• HY2.0-4P interface

Include

• 1x UNIT-CO2
• 1x HY2.0-4P cable (20CM)

Applications

• Environmental sensing
• Air quality
• Ventilation studies

Specifications

PinMap

Schematic

Related Link

• Datasheet

  • SCD40
  • SY8089AAAC

Model Size

Example

#include <Arduino.h>
#include <Wire.h>

// SCD4x
const int16_t SCD_ADDRESS = 0x62;

void setup() {
    // check in your settings that the right speed is selected
    Serial.begin(115200);
    // wait for serial connection from PC
    // comment the following line if you'd like the output
    // without waiting for the interface being ready
    while (!Serial)
        ;

    // output format
    Serial.println("CO2(ppm)\tTemperature(degC)\tRelativeHumidity(percent)");

    // init I2C
    Wire.begin();

    // wait until sensors are ready, > 1000 ms according to datasheet
    delay(1000);

    // start scd measurement in periodic mode, will update every 5 s
    Wire.beginTransmission(SCD_ADDRESS);
    Wire.write(0x21);
    Wire.write(0xb1);
    Wire.endTransmission();

    // wait for first measurement to be finished
    delay(5000);
}

void loop() {
    float co2, temperature, humidity;
    uint8_t data[12], counter;

    // send read data command
    Wire.beginTransmission(SCD_ADDRESS);
    Wire.write(0xec);
    Wire.write(0x05);
    Wire.endTransmission();

    // read measurement data: 2 bytes co2, 1 byte CRC,
    // 2 bytes T, 1 byte CRC, 2 bytes RH, 1 byte CRC,
    // 2 bytes sensor status, 1 byte CRC
    // stop reading after 12 bytes (not used)
    // other data like  ASC not included
    Wire.requestFrom(SCD_ADDRESS, 12);
    counter = 0;
    while (Wire.available()) {
        data[counter++] = Wire.read();
    }

    // floating point conversion according to datasheet
    co2 = (float)((uint16_t)data[0] << 8 | data[1]);
    // convert T in degC
    temperature = -45 + 175 * (float)((uint16_t)data[3] << 8 | data[4]) / 65536;
    // convert RH in %
    humidity = 100 * (float)((uint16_t)data[6] << 8 | data[7]) / 65536;

    Serial.print(co2);
    Serial.print("\t");
    Serial.print(temperature);
    Serial.print("\t");
    Serial.print(humidity);
    Serial.println();

    // wait 5 s for next measurement
    delay(5000);
}

Arduino

• M5Unit-CO2 with M5Atom
• M5Unit-CO2 with M5AtomS3
• M5Unit-CO2 with M5AtomS3Lite
• M5Unit-CO2 with M5Core
• M5Unit-CO2 with M5Core2
• M5Unit-CO2 with M5StickC
• M5Unit-CO2 with M5StickCPlus

UIFlow

UIFlow1.0 Unit co2 Docs

UIFlow1.0 Unit co2 Docs

How to use Unit co2 and related API instructions in the UIFlow1.0