Merge pull request #79 from beta-tester/master

BH1750 MTreg min is 31 in the datasheet

Author: claws

examples/BH1750autoadjust/BH1750autoadjust.ino

@@ -9,7 +9,7 @@ After the measurement the MTreg value is changed according to the result:
 lux > 40000 ==> MTreg =  32
 lux < 40000 ==> MTreg =  69  (default)
 lux <    10 ==> MTreg = 138
-Remember to test your specific sensor! Maybe the MTreg value range from 32
+Remember to test your specific sensor! Maybe the MTreg value range from 31
 up to 254 is not applicable to your unit.
 
 Connections

src/BH1750.cpp

@@ -138,13 +138,12 @@ bool BH1750::configure(Mode mode) {
 /**
  * Configure BH1750 MTreg value
  * MT reg = Measurement Time register
- * @param MTreg a value between 32 and 254. Default: 69
+ * @param MTreg a value between 31 and 254. Default: 69
  * @return bool true if MTReg successful set
  * 		false if MTreg not changed or parameter out of range
  */
 bool BH1750::setMTreg(byte MTreg) {
-  // Bug: lowest value seems to be 32!
-  if (MTreg <= 31 || MTreg > 254) {
+  if (MTreg < BH1750_MTREG_MIN || MTreg > BH1750_MTREG_MAX) {
     Serial.println(F("[BH1750] ERROR: MTreg out of range"));
     return false;
   }

src/BH1750.h

@@ -38,6 +38,8 @@
 
 // Default MTreg value
 #define BH1750_DEFAULT_MTREG 69
+#define BH1750_MTREG_MIN 31
+#define BH1750_MTREG_MAX 254
 
 class BH1750 {