Fixed rounding bug from issue 8 on breakout board.

See issue sparkfun/Qwiic_BME280_CCS811_Combo#8

Author: nseidle

src/SparkFunCCS811.cpp

@@ -465,21 +465,32 @@ CCS811Core::status CCS811::setEnvironmentalData( float relativeHumidity, float t
 	byte envData[4];
 
 	//Split value into 7-bit integer and 9-bit fractional
-	envData[0] = ((rH % 1000) / 100) > 7 ? (rH / 1000 + 1) << 1 : (rH / 1000) << 1;
+	
+	//Incorrect way from datasheet.
+	//envData[0] = ((rH % 1000) / 100) > 7 ? (rH / 1000 + 1) << 1 : (rH / 1000) << 1;
+	//envData[1] = 0; //CCS811 only supports increments of 0.5 so bits 7-0 will always be zero
+	//if (((rH % 1000) / 100) > 2 && (((rH % 1000) / 100) < 8))
+	//{
+	//	envData[0] |= 1; //Set 9th bit of fractional to indicate 0.5%
+	//}
+	
+	//Correct rounding. See issue 8: https://github.com/sparkfun/Qwiic_BME280_CCS811_Combo/issues/8
+	envData[0] = (rH + 250) / 500;
 	envData[1] = 0; //CCS811 only supports increments of 0.5 so bits 7-0 will always be zero
-	if (((rH % 1000) / 100) > 2 && (((rH % 1000) / 100) < 8))
-	{
-		envData[0] |= 1; //Set 9th bit of fractional to indicate 0.5%
-	}
 
 	temp += 25000; //Add the 25C offset
 	//Split value into 7-bit integer and 9-bit fractional
-	envData[2] = ((temp % 1000) / 100) > 7 ? (temp / 1000 + 1) << 1 : (temp / 1000) << 1;
+	//envData[2] = ((temp % 1000) / 100) > 7 ? (temp / 1000 + 1) << 1 : (temp / 1000) << 1;
+	//envData[3] = 0;
+	//if (((temp % 1000) / 100) > 2 && (((temp % 1000) / 100) < 8))
+	//{
+	//	envData[2] |= 1;  //Set 9th bit of fractional to indicate 0.5C
+	//}
+	
+	//Correct rounding
+	envData[2] = (temp + 250) / 500;
 	envData[3] = 0;
-	if (((temp % 1000) / 100) > 2 && (((temp % 1000) / 100) < 8))
-	{
-		envData[2] |= 1;  //Set 9th bit of fractional to indicate 0.5C
-	}
+	
 	CCS811Core::status returnError = multiWriteRegister(CSS811_ENV_DATA, envData, 4);
 	return returnError;
 }