1 files changed, 154 insertions, 0 deletions

diff --git a/CCS811.cpp b/CCS811.cpp
new file mode 100644
index 0000000..05b71c0
--- /dev/null
+++ b/CCS811.cpp
@@ -0,0 +1,154 @@
+#include "CCS811.h"
+
+int CCS811::begin(void)
+{
+    uint8_t id=0;
+    Wire.begin();
+    softReset();
+    delay(100);
+    if(readReg(CCS811_REG_HW_ID,&id,1) != 1){DBG("");
+        DBG("bus data access error");DBG("");
+        return ERR_DATA_BUS;DBG("");
+    }
+
+    DBG("real sensor id=");DBG(id);
+    if(id != CCS811_HW_ID){DBG("");
+        delay(1);
+        return ERR_IC_VERSION;
+    }
+    writeReg(CCS811_BOOTLOADER_APP_START, NULL, 0);
+    setMeasurementMode(0,0,eMode4);
+    setInTempHum(25, 50);
+    return ERR_OK;
+}
+
+void CCS811::softReset(){
+    uint8_t value[4] = {0x11, 0xE5, 0x72, 0x8A};
+    writeReg(CCS811_REG_SW_RESET, value, 4);
+}
+
+bool CCS811::checkDataReady()
+{
+    int8_t status[1] = {0};
+    readReg(CCS811_REG_STATUS, status, 1);
+    DBG(status[0],HEX);
+    if(!((status[0] >> 3) & 0x01))
+        return false;
+    else 
+        return true;
+}
+
+uint16_t CCS811::readBaseLine(){
+    uint8_t buffer[2];
+    readReg(CCS811_REG_BASELINE, buffer, 2);
+    return buffer[0]<<8|buffer[1];
+}
+
+void CCS811::writeBaseLine(uint16_t baseLine){
+    uint8_t buffer[2];
+    
+    buffer[0] = baseLine>>8;
+    buffer[1] = baseLine;
+    writeReg(CCS811_REG_BASELINE, buffer, 2);
+}
+
+void CCS811::setMeasurementMode(uint8_t thresh, uint8_t interrupt, eDRIVE_MODE_t mode){
+    uint8_t measurement[1] = {0};
+    measurement[0] = (thresh << 2) | (interrupt << 3) | (mode << 4);
+    writeReg(CCS811_REG_MEAS_MODE, measurement, 1);
+}
+
+void CCS811::setMeasCycle(eCycle_t cycle){
+    uint8_t measurement[1] = {0};   
+    measurement[0] = cycle << 4;
+    writeReg(CCS811_REG_MEAS_MODE, measurement, 1);
+}
+
+uint8_t CCS811::getMeasurementMode(){
+    uint8_t meas[1] = {0};
+    readReg(CCS811_REG_MEAS_MODE, meas, 1);
+    return meas[0];
+}
+
+void CCS811::setThresholds(uint16_t lowToMed, uint16_t medToHigh)
+{
+    uint8_t buffer[] = {(uint8_t)((lowToMed >> 8) & 0xF),
+                        (uint8_t)(lowToMed & 0xF),
+                        (uint8_t)((medToHigh >> 8) & 0xF),
+                        (uint8_t)(medToHigh & 0xF)};
+    
+    writeReg(CCS811_REG_THRESHOLDS, buffer, 5);
+    uint8_t buf[1];
+    readReg(CCS811_REG_THRESHOLDS, buf, 1);
+    Serial.println(buf[0],HEX);
+}
+
+uint16_t CCS811::getCO2PPM(){
+    uint8_t buffer[8];
+    readReg(CCS811_REG_ALG_RESULT_DATA, buffer, 8);
+    eCO2 = (((uint16_t)buffer[0] << 8) | (uint16_t)buffer[1]);
+    return eCO2;
+}
+
+uint16_t CCS811::getTVOCPPB(){
+    uint8_t buffer[8];
+    readReg(CCS811_REG_ALG_RESULT_DATA, buffer, 8);
+    eTVOC = (((uint16_t)buffer[2] << 8) | (uint16_t)buffer[3]);
+    return eTVOC;
+}
+
+void CCS811::setInTempHum(float temperature, float humidity)    // compensate for temperature and relative humidity
+{
+    int _temp, _rh;
+    if(temperature>0)
+        _temp = (int)temperature + 0.5;  // this will round off the floating point to the nearest integer value
+    else if(temperature<0) // account for negative temperatures
+        _temp = (int)temperature - 0.5;
+    _temp = _temp + 25;  // temperature high byte is stored as T+25°C in the sensor's memory so the value of byte is positive
+    _rh = (int)humidity + 0.5;  // this will round off the floating point to the nearest integer value
+    
+    uint8_t envData[4];
+    
+    envData[0] = _rh << 1;  // shift the binary number to left by 1. This is stored as a 7-bit value
+    envData[1] = 0;  // most significant fractional bit. Using 0 here - gives us accuracy of +/-1%. Current firmware (2016) only supports fractional increments of 0.5
+    envData[2] = _temp << 1;
+    envData[3] = 0;
+    
+    writeReg(CCS811_REG_ENV_DATA, &envData, 4);
+}
+
+void CCS811::writeReg(uint8_t reg, const void* pBuf, size_t size)
+{
+    if(pBuf == NULL){
+        DBG("pBuf ERROR!! : null pointer");
+    }
+    uint8_t * _pBuf = (uint8_t *)pBuf;
+    _pWire->beginTransmission(_deviceAddr);
+    _pWire->write(&reg, 1);
+    
+    for(uint16_t i = 0; i < size; i++){
+        _pWire->write(_pBuf[i]);
+    }
+    _pWire->endTransmission();
+}
+
+uint8_t CCS811::readReg(uint8_t reg, const void* pBuf, size_t size)
+{
+    if(pBuf == NULL){
+        DBG("pBuf ERROR!! : null pointer");
+    }
+    uint8_t * _pBuf = (uint8_t *)pBuf;
+    _pWire->beginTransmission(_deviceAddr);
+    _pWire->write(&reg, 1);
+    
+    if( _pWire->endTransmission() != 0){
+        return 0;
+    }
+
+    _pWire->requestFrom(_deviceAddr, (uint8_t) size);
+    for(uint16_t i = 0; i < size; i++){
+        _pBuf[i] = _pWire->read();
+    }
+    _pWire->endTransmission();
+    return size;
+}