Sensirion SCD30 Modbus

Arduino library for Sensirion SCD30 sensor via UART Modbus

Getting Started

I was working on a project where I2C protocol was not an option, so I developed this library to communicate via UART and modbus protocol. This library is based on Adafruit SCD30 library so all method and variable names are basically the same.

Basic example

// Basic demo
#include <scd30_modbus.h>

SCD30_Modbus scd30;

void setup(void) {
   Serial.begin(9600);
   while (!Serial) delay(10);

   Serial.println("SCD30 modbus test!");

   // Initialize sensor
   scd30.begin(&Serial1)

   // /*** Adjust the rate at which measurements are taken, from 2-1800 seconds */
   // if (!scd30.setMeasurementInterval(2)){
   //    Serial.println("ERROR! Failed to set measurement interval");
   //    while(1){ delay(10);}
   // }
   Serial.print("Measurement Interval: "); 
   Serial.print(scd30.getMeasurementInterval()); 
   Serial.println(" seconds");

   // /*** Restart continuous measurement with a pressure offset from 700 to 1400 millibar.
   //  * Giving no argument or setting the offset to 0 will disable offset correction
   //  */
   if (!scd30.startContinuousMeasurement(0)){
     Serial.println("ERROR! Failed to set ambient pressure offset");
     while(1){ delay(10);}
   }
   Serial.print("Ambient pressure offset: ");
   Serial.print(scd30.getAmbientPressureOffset());
   Serial.println(" mBar");

   // /*** Set an altitude offset in meters above sea level.
   //  * Offset value stored in non-volatile memory of SCD30.
   //  * Setting an altitude offset will override any pressure offset.
   //  */
   // if (!scd30.setAltitudeOffset(0)){
   //   Serial.println("ERROR! Failed to set measurement interval");
   //   while(1){ delay(10);}
   // }
   Serial.print("Altitude offset: ");
   Serial.print(scd30.getAltitudeOffset());
   Serial.println(" meters");

   // ** Set a temperature offset in hundredths of a degree celcius.
   //  * Offset value stored in non-volatile memory of SCD30.
   // if (!scd30.setTemperatureOffset(0)){ // 19.84 degrees celcius
   //    Serial.println("ERROR! Failed to set temperature offset");
   //    while(1){ delay(10);}
   // }
   Serial.print("Temperature offset: ");
   Serial.print((float)scd30.getTemperatureOffset()/100.0);
   Serial.println(" degrees C");

   // /*** Force the sensor to recalibrate with the given reference value
   //  * from 400-2000 ppm. Writing a recalibration reference will overwrite
   //  * any previous self calibration values.
   //  * Reference value stored in non-volatile memory of SCD30.
   //  */
   // if (!scd30.forceRecalibrationWithReference(400)){
   //    Serial.println("ERROR! Failed to force recalibration with reference");
   //    while(1){ delay(10);}
   // }
   Serial.print("Forced Recalibration reference: ");
   Serial.print(scd30.getForcedCalibrationReference());
   Serial.println(" ppm");

   // /*** Enable or disable automatic self calibration (ASC).
   //  * Parameter stored in non-volatile memory of SCD30.
   //  * Enabling self calibration will override any previously set
   //  * forced calibration value.
   //  * ASC needs continuous operation with at least 1 hour
   //  * 400ppm CO2 concentration daily.
   //  */
   // if (!scd30.selfCalibrationEnabled(true)){
   //    Serial.println("ERROR! Failed to enable or disable self calibration");
   //    while(1){ delay(10);}
   // }
   if (scd30.selfCalibrationEnabled()) {
      Serial.print("Self calibration enabled");
   } else {
      Serial.print("Self calibration disabled");
   }

void loop() {
   if (scd30.dataReady()){
      Serial.println("Data available!");

      if (!scd30.read()){ Serial.println("Error reading sensor data"); return; }

      Serial.print("Temperature: ");
      Serial.print(scd30.temperature);
      Serial.println(" degrees C");

      Serial.print("Relative Humidity: ");
      Serial.print(scd30.relative_humidity);
      Serial.println(" %");

      Serial.print("CO2: ");
      Serial.print(scd30.CO2, 3);
      Serial.println(" ppm");
      Serial.println("");
   }

   delay(2000);
}

Author

• Robert Cojocaru - GitHub - Robertndrei

License

This project is licensed under the MIT License - see the LICENSE.md file for details