Fix One-Time use case

BH1750.cpp

@@ -56,6 +56,7 @@ BH1750::BH1750(byte addr) {
 
 }
 
+
 /**
  * Begin I2C and configure sensor
  * @param SDA Date SCL Clock mode Measurment mode
@@ -64,13 +65,15 @@ BH1750::BH1750(byte addr) {
 void BH1750::begin(uint8_t SDA, uint8_t SCL, uint8_t mode) {
 
   // allow config of pins
-  Wire.begin(SDA,SCL);
+  Wire.begin(SDA, SCL);
 
   // Configure sensor in specified mode
   configure(mode);
+
 }
 #endif
 
+
 /**
  * Begin I2C and configure sensor
  * @param mode Measurment mode
@@ -87,12 +90,13 @@ void BH1750::begin(uint8_t mode) {
 
 
 /**
- * Configurate BH1750 with specified working mode
+ * Configure BH1750 with specified working mode
  * @param mode Measurment mode
  */
 void BH1750::configure(uint8_t mode) {
 
-  // Check, is measurment mode exist
+
+  // Check measurment mode is valid
   switch (mode) {
 
     case BH1750_CONTINUOUS_HIGH_RES_MODE:
@@ -102,12 +106,15 @@ void BH1750::configure(uint8_t mode) {
     case BH1750_ONE_TIME_HIGH_RES_MODE_2:
     case BH1750_ONE_TIME_LOW_RES_MODE:
 
+      // Save mode so it can be restored when One-Time modes are used.
+      BH1750_MODE = mode;
+
       // Send mode to sensor
       Wire.beginTransmission(BH1750_I2CADDR);
-      __wire_write((uint8_t)mode);
+      __wire_write((uint8_t)BH1750_MODE);
       Wire.endTransmission();
 
-      // Wait few moments for waking up
+      // Wait a few moments to wake up
       _delay_ms(10);
       break;
 
@@ -127,13 +134,23 @@ void BH1750::configure(uint8_t mode) {
 
 /**
  * Read light level from sensor
- * @return  Lightness in lux (0 ~ 65535)
+ * @return Light level in lux (0 ~ 65535)
  */
 uint16_t BH1750::readLightLevel(void) {
 
   // Measurment result will be stored here
   uint16_t level;
 
+  // One-Time modes apparently need to be re-applied after power-up
+  // to ensure the chip is awake.
+  switch (BH1750_MODE) {
+    case BH1750_ONE_TIME_HIGH_RES_MODE:
+    case BH1750_ONE_TIME_HIGH_RES_MODE_2:
+    case BH1750_ONE_TIME_LOW_RES_MODE:
+      __wire_write((uint8_t)BH1750_MODE);
+      break;
+  }
+
   // Read two bytes from sensor
   Wire.requestFrom(BH1750_I2CADDR, 2);
 
@@ -142,7 +159,7 @@ uint16_t BH1750::readLightLevel(void) {
   level <<= 8;
   level |= __wire_read();
 
-  // Send raw value if debug enabled
+  // Print raw value if debug enabled
   #ifdef BH1750_DEBUG
     Serial.print(F("[BH1750] Raw value: "));
     Serial.println(level);
@@ -151,7 +168,7 @@ uint16_t BH1750::readLightLevel(void) {
   // Convert raw value to lux
   level /= 1.2;
 
-  // Send converted value, if debug enabled
+  // Print converted value if debug enabled
   #ifdef BH1750_DEBUG
     Serial.print(F("[BH1750] Converted value: "));
     Serial.println(level);

BH1750.h

@@ -70,6 +70,7 @@ class BH1750 {
 
   private:
     int BH1750_I2CADDR;
+    uint8_t BH1750_MODE;
 
 };
 

build-examples.bash

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+#
+# A simple script to automate building BH1750 examples.
+#
+# Example (MacOSX):
+#     $ ARDUINO_IDE_PATH=/Applications/Arduino.app/Contents/Java ./build-examples.bash
+#
+
+# Path to script directory.
+SCRIPTPATH="$( cd "$(dirname "$0")" ; pwd -P )"
+LIBNAME="$(basename "$SCRIPTPATH")"
+
+if [[ -z "${ARDUINO_IDE_PATH}" ]]; then
+  echo "ARDUINO_IDE_PATH env var is not set"
+  exit 1
+fi
+
+# Link BH1750 library into Arduino libraries directory
+ln -s $SCRIPTPATH $ARDUINO_IDE_PATH/libraries/
+
+cd $ARDUINO_IDE_PATH
+
+for sketch in `find $SCRIPTPATH/examples -name '*.ino'`
+do
+  echo "Compiling $sketch"
+  ./arduino-builder -hardware ./hardware -tools ./hardware/tools/avr -tools ./tools-builder -libraries ./libraries -fqbn arduino:avr:uno $sketch
+  # ./arduino-builder -hardware ./hardware -tools ./hardware/tools/avr -tools ./tools-builder -libraries ./libraries -fqbn esp8266:esp8266:generic $sketch
+done
+
+# Unlink BH1750 library from Arduino libraries directory
+unlink $ARDUINO_IDE_PATH/libraries/$LIBNAME

examples/BH1750advanced/BH1750advanced.ino

@@ -12,9 +12,9 @@
     SDA -> SDA (A4 on Arduino Uno, Leonardo, etc or 20 on Mega and Due)
     ADD -> GND or VCC (see below)
 
-  ADD pin uses to set sensor I2C address. If it has voltage greater or equal to
-  0.7VCC voltage (as example, you've connected it to VCC) - sensor address will be
-  0x5C. In other case (if ADD voltage less than 0.7 * VCC) - sensor address will
+  ADD pin is used to set sensor I2C address. If it has voltage greater or equal to
+  0.7VCC voltage (e.g. you've connected it to VCC) the sensor address will be
+  0x5C. In other case (if ADD voltage less than 0.7 * VCC) the sensor address will
   be 0x23 (by default).
 
 */

examples/BH1750test/BH1750test.ino

@@ -13,9 +13,9 @@
     SDA -> SDA (A4 on Arduino Uno, Leonardo, etc or 20 on Mega and Due on esp8266 free selectable)
     ADD -> (not connected) or GND
 
-  ADD pin uses to set sensor I2C address. If it has voltage greater or equal to
-  0.7VCC voltage (as example, you've connected it to VCC) - sensor address will be
-  0x5C. In other case (if ADD voltage less than 0.7 * VCC) - sensor address will
+  ADD pin is used to set sensor I2C address. If it has voltage greater or equal to
+  0.7VCC voltage (e.g. you've connected it to VCC) the sensor address will be
+  0x5C. In other case (if ADD voltage less than 0.7 * VCC) the sensor address will
   be 0x23 (by default).
 
 */
@@ -29,7 +29,7 @@ void setup(){
 
   Serial.begin(9600);
   lightMeter.begin();
-  //lightMeter.begin(begin(D4, D3)); //use this line on a esp8266
+  //lightMeter.begin(begin(D4, D3)); // use this line on a esp8266 to modify pins
   Serial.println(F("BH1750 Test"));
 
 }