This project uses a CJMCU-8118 board bought on Taobao, hosting an HDC1080 humidity and temperature sensor and a CCS811 digital gas sensor. It requires the usual 4 pins for I2C, plus 2 pins for INTerrupt and WAKe for the CCS811 (should you want to use an interrupt-based code, as opposed to straight readings).
You will need two libraries, from ClosedCube and Sparkfun.
#include <ClosedCube_HDC1080.h>
// Click here to get the library: http:https://librarymanager/All#ClosedCube_HDC1080
#include <SparkFunCCS811.h>
// Click here to get the library: http:https://librarymanager/All#SparkFun_CCS811By default the HDC1080 is set to 14-bit resolution for Temperature and Humidity. You can play with the registers by setting the proper bits in HDC1080_Registers:
typedef union {
uint8_t rawData;
struct {
uint8_t HumidityMeasurementResolution : 2;
//00: 14-bit
//01: 11-bit
//10: 8-bit
uint8_t TemperatureMeasurementResolution : 1;
//0: 14-bit
//1: 11-bit
uint8_t BatteryStatus : 1;
//0: Battery voltage > 2.8V (read only)
//1: Battery voltage < 2.8V (read only)
uint8_t ModeOfAcquisition : 1;
//0: Temp *or* RH
//1: Both
uint8_t Heater : 1;
//0: Disabled
//1: Enabled
uint8_t ReservedAgain : 1;
uint8_t SoftwareReset : 1;
//0: Normal Operation, this bit self-clears
//1: Software Reset
};
} HDC1080_Registers;See this PDF for more details.
Use this function to set the register:
void writeRegister(HDC1080_Registers reg);
I added some code in setup() to show how to read the configuration and look under the hood:
HDC1080_Registers reg = hdc1080.readRegister();
Serial.print("Battery: 0x");
Serial.println(reg.BatteryStatus, HEX);
Serial.print("Heater: 0x");
Serial.println(reg.Heater, HEX);
Serial.print("HumidityMeasurementResolution: 0x");
Serial.println(reg.HumidityMeasurementResolution, HEX);
Serial.print("TemperatureMeasurementResolution: 0x");
Serial.println(reg.TemperatureMeasurementResolution, HEX);This confirms the default settings:
Battery: 0x0
Heater: 0x0
HumidityMeasurementResolution: 0x0
TemperatureMeasurementResolution: 0x0