2018-03-31 15:26:00 +01:00
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#include <Wire.h>
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#include "Adafruit_SGP30.h"
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Adafruit_SGP30 sgp;
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2019-05-18 13:16:29 +01:00
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/* return absolute humidity [mg/m^3] with approximation formula
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* @param temperature [°C]
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* @param humidity [%RH]
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*/
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uint32_t getAbsoluteHumidity(float temperature, float humidity) {
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// approximation formula from Sensirion SGP30 Driver Integration chapter 3.15
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const float absoluteHumidity = 216.7f * ((humidity / 100.0f) * 6.112f * exp((17.62f * temperature) / (243.12f + temperature)) / (273.15f + temperature)); // [g/m^3]
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const uint32_t absoluteHumidityScaled = static_cast<uint32_t>(1000.0f * absoluteHumidity); // [mg/m^3]
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return absoluteHumidityScaled;
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}
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2018-03-31 15:26:00 +01:00
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void setup() {
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Serial.begin(9600);
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Serial.println("SGP30 test");
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if (! sgp.begin()){
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Serial.println("Sensor not found :(");
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while (1);
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}
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Serial.print("Found SGP30 serial #");
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Serial.print(sgp.serialnumber[0], HEX);
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Serial.print(sgp.serialnumber[1], HEX);
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Serial.println(sgp.serialnumber[2], HEX);
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// If you have a baseline measurement from before you can assign it to start, to 'self-calibrate'
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//sgp.setIAQBaseline(0x8E68, 0x8F41); // Will vary for each sensor!
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}
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int counter = 0;
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void loop() {
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2019-05-18 13:16:29 +01:00
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// If you have a temperature / humidity sensor, you can set the absolute humidity to enable the humditiy compensation for the air quality signals
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//float temperature = 22.1; // [°C]
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//float humidity = 45.2; // [%RH]
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//sgp.setHumidity(getAbsoluteHumidity(temperature, humidity));
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2018-03-31 15:26:00 +01:00
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if (! sgp.IAQmeasure()) {
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Serial.println("Measurement failed");
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return;
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}
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Serial.print("TVOC "); Serial.print(sgp.TVOC); Serial.print(" ppb\t");
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Serial.print("eCO2 "); Serial.print(sgp.eCO2); Serial.println(" ppm");
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delay(1000);
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counter++;
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if (counter == 30) {
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counter = 0;
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uint16_t TVOC_base, eCO2_base;
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if (! sgp.getIAQBaseline(&eCO2_base, &TVOC_base)) {
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Serial.println("Failed to get baseline readings");
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return;
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}
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Serial.print("****Baseline values: eCO2: 0x"); Serial.print(eCO2_base, HEX);
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Serial.print(" & TVOC: 0x"); Serial.println(TVOC_base, HEX);
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}
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}
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