From ea801213f1f4d36153f3f3d9904cc146ececc91f Mon Sep 17 00:00:00 2001
From: coelner <waenger@googlemail.com>
Date: Wed, 14 Aug 2019 19:37:18 +0200
Subject: [PATCH] fix continuous mode reset

---
 BH1750.cpp | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/BH1750.cpp b/BH1750.cpp
index 86908cf..e039a2f 100644
--- a/BH1750.cpp
+++ b/BH1750.cpp
@@ -151,15 +151,15 @@ bool BH1750::setMTreg(byte MTreg) {
   // Send MTreg and the current mode to the sensor
   //   High bit: 01000_MT[7,6,5]
   //    Low bit: 011_MT[4,3,2,1,0]
-  Wire.beginTransmission(BH1750_I2CADDR);
-  __wire_write((0b01000 << 3) | (MTreg >> 5));
-  ack = Wire.endTransmission();
-  Wire.beginTransmission(BH1750_I2CADDR);
-  __wire_write((0b011 << 5 )  | (MTreg & 0b111));
-  ack = ack | Wire.endTransmission();
-  Wire.beginTransmission(BH1750_I2CADDR);
-  __wire_write(BH1750_MODE);
-  ack = ack | Wire.endTransmission();
+  _wire->beginTransmission(BH1750_I2CADDR);
+  _wire->write((0b01000 << 3) | (MTreg >> 5));
+  ack = _wire->endTransmission();
+  _wire->beginTransmission(BH1750_I2CADDR);
+  _wire->write((0b011 << 5 )  | (MTreg & 0b11111));
+  ack = ack | _wire->endTransmission();
+  _wire->beginTransmission(BH1750_I2CADDR);
+  _wire->write(BH1750_MODE);
+  ack = ack | _wire->endTransmission();
 
   // Wait a few moments to wake up
   _delay_ms(10);
@@ -219,11 +219,6 @@ float BH1750::readLightLevel(bool maxWait) {
   // Measurement result will be stored here
   float level = -1.0;
 
-  // Send mode to sensor
-  Wire.beginTransmission(BH1750_I2CADDR);
-  __wire_write((uint8_t)BH1750_MODE);
-  Wire.endTransmission();
-
   // Wait for measurement to be taken.
   // Measurements have a maximum measurement time and a typical measurement
   // time. The maxWait argument determines which measurement wait time is
@@ -237,10 +232,18 @@ float BH1750::readLightLevel(bool maxWait) {
   switch (BH1750_MODE) {
 
     case BH1750::ONE_TIME_LOW_RES_MODE:
+      // Send mode to sensor
+      _wire->beginTransmission(BH1750_I2CADDR);
+      _wire->write((uint8_t)BH1750_MODE);
+      _wire->endTransmission();
       maxWait ? _delay_ms(24 * BH1750_MTreg/(byte)BH1750_DEFAULT_MTREG) : _delay_ms(16 * BH1750_MTreg/(byte)BH1750_DEFAULT_MTREG);
       break;
     case BH1750::ONE_TIME_HIGH_RES_MODE:
     case BH1750::ONE_TIME_HIGH_RES_MODE_2:
+      // Send mode to sensor
+      _wire->beginTransmission(BH1750_I2CADDR);
+      _wire->write((uint8_t)BH1750_MODE);
+      _wire->endTransmission();
       maxWait ? _delay_ms(180 * BH1750_MTreg/(byte)BH1750_DEFAULT_MTREG) :_delay_ms(120 * BH1750_MTreg/(byte)BH1750_DEFAULT_MTREG);
       break;
     default: