From 3530a81e7a91c2b2a5ea9d2baff55ed76eeeb941 Mon Sep 17 00:00:00 2001
From: Ewan Parker <34030942+ewpa@users.noreply.github.com>
Date: Mon, 26 Aug 2019 21:42:23 +0100
Subject: [PATCH] Change the method of converting the 12 bit sampled ADC value
 to a voltage. Currently this is performed by scaling the value of 0 to 4095
 to a value of 0.0 to 5.0 (or 10.0) volts.  However the datasheet states that
 the ADC measures the voltage in increments of 1.25 mV (or 2.50 mV).  So we
 simply multiply the ADC reading by the appropriate mV increment.

---
 library.properties |  2 +-
 src/MAX17043.h     |  6 +++---
 src/MAX17044.h     |  6 +++---
 src/MAX1704X.cpp   | 11 ++++++-----
 src/MAX1704X.h     |  4 ++--
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/library.properties b/library.properties
index 89deba1..818df93 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=MAX1704X
-version=1.0.0
+version=1.0.1
 author=Daniel Porrey <daniel.porrey@hotmail.com>
 maintainer=Daniel Porrey <daniel.porrey@hotmail.com>
 sentence=Arduino library for MAX17043/MAX17044 lithium ion battery fuel gauge.
diff --git a/src/MAX17043.h b/src/MAX17043.h
index b1a8a5b..9f899d1 100644
--- a/src/MAX17043.h
+++ b/src/MAX17043.h
@@ -1,7 +1,7 @@
 /*
  * MAX1704X Arduino Library for MAX17043 and MAX17044 Fuel Gauge.
  *
- * Version 1.0.0 
+ * Version 1.0.1
  * Copyright © 2018 Daniel Porrey. All Rights Reserved.
  * https://github.com/porrey/max1704x
  *
@@ -30,8 +30,8 @@ extern MAX1704X FuelGauge;
 
 // ***
 // *** The MAX17043 is a one-cell device with a
-// *** a voltage measurement range of 0 to 5 V.
+// *** a voltage measurement range of 0 to 5 V in 1.25 mV increments.
 // ***
-MAX1704X FuelGauge = MAX1704X(5);
+MAX1704X FuelGauge = MAX1704X(1.25);
 
 #endif
diff --git a/src/MAX17044.h b/src/MAX17044.h
index 048ed52..62d4fe3 100644
--- a/src/MAX17044.h
+++ b/src/MAX17044.h
@@ -1,7 +1,7 @@
 /*
  * MAX1704X Arduino Library for MAX17043 and MAX17044 Fuel Gauge.
  *
- * Version 1.0.0 
+ * Version 1.0.1
  * Copyright © 2018 Daniel Porrey. All Rights Reserved.
  * https://github.com/porrey/max1704x
  *
@@ -30,8 +30,8 @@ extern MAX1704X FuelGauge;
 
 // ***
 // *** The MAX17044 is a two-cell device with a
-// *** a voltage measurement range of 0 to 10 V.
+// *** a voltage measurement range of 0 to 10 V in 2.50 mV increments.
 // ***
-MAX1704X FuelGauge = MAX1704X(10);
+MAX1704X FuelGauge = MAX1704X(2.50);
 
 #endif
diff --git a/src/MAX1704X.cpp b/src/MAX1704X.cpp
index 405b1e5..2e8cf5f 100644
--- a/src/MAX1704X.cpp
+++ b/src/MAX1704X.cpp
@@ -1,7 +1,7 @@
 /*
  * MAX1704X Arduino Library for MAX17043 and MAX17044 Fuel Gauge.
  *
- * Version 1.0.0 
+ * Version 1.0.1
  * Copyright © 2018 Daniel Porrey. All Rights Reserved.
  * https://github.com/porrey/max1704x
  *
@@ -23,9 +23,9 @@
  */
 #include "MAX1704X.h"
 
-MAX1704X::MAX1704X(float maxVoltage)
+MAX1704X::MAX1704X(float voltageIncrement)
 {
-  this->_maxVoltage = maxVoltage;
+  this->_voltageIncrement = voltageIncrement;
 }
 
 void MAX1704X::begin()
@@ -44,9 +44,10 @@ uint16_t MAX1704X::adc()
 float MAX1704X::voltage()
 {
   // ***
-  // *** The MAX1704X is a 12-bit ADC measuring 0 to 5 volts.
+  // *** The MAX1704X has a 12-bit ADC measuring 0 to 5 or 10 Volts in differing
+  // *** increments.
   // ***
-  return (float)(this->adc() / 4096.0 * this->_maxVoltage);
+  return (float)(this->adc() * this->_voltageIncrement);
 }
 
 float MAX1704X::percent()
diff --git a/src/MAX1704X.h b/src/MAX1704X.h
index 8d27d92..fbd6885 100644
--- a/src/MAX1704X.h
+++ b/src/MAX1704X.h
@@ -1,7 +1,7 @@
 /*
  * MAX1704X Arduino Library for MAX17043 and MAX17044 Fuel Gauge.
  *
- * Version 1.0.0 
+ * Version 1.0.1
  * Copyright © 2018 Daniel Porrey. All Rights Reserved.
  * https://github.com/porrey/max1704x
  *
@@ -65,7 +65,7 @@ class MAX1704X
     void setThreshold(uint8_t threshold);
 
   protected:
-    float _maxVoltage;
+    float _voltageIncrement;
     uint8_t thresholdToConfig(uint8_t threshold);
     uint8_t configToThreshold(uint8_t config);
     uint16_t readRegister16(uint8_t registerId);