2 files changed, 38 insertions, 10 deletions

diff --git a/src/ADS1115_WE.cpp b/src/ADS1115_WE.cpp
index 01cb4fa..47ed03d 100644
--- a/src/ADS1115_WE.cpp
+++ b/src/ADS1115_WE.cpp
@@ -41,6 +41,7 @@ bool ADS1115_WE::init(){
     writeRegister(ADS1115_LO_THRESH_REG, 0x8000);

     writeRegister(ADS1115_HI_THRESH_REG, 0x7FFF);

     deviceMeasureMode = ADS1115_SINGLE;

+    autoRangeMode = false;

     return 1;

 }

 

@@ -153,22 +154,22 @@ void ADS1115_WE::setAutoRange(){
         delayAccToRate(rate);

     }

     

-    float result = abs(getResult_mV());

+    int16_t rawResult = abs(readRegister(ADS1115_CONV_REG));

     range optRange = ADS1115_RANGE_6144;

     

-    if(result < 205.0){

+    if(rawResult < 1093){

         optRange = ADS1115_RANGE_0256;

     }

-    else if(result < 410.0){

+    else if(rawResult < 2185){

         optRange = ADS1115_RANGE_0512;

     }

-    else if(result < 820.0){

+    else if(rawResult < 4370){

         optRange = ADS1115_RANGE_1024;

     }

-    else if(result < 1640.0){

+    else if(rawResult < 8738){

         optRange = ADS1115_RANGE_2048;

     }

-    else if(result < 3280.0){

+    else if(rawResult < 17476){

         optRange = ADS1115_RANGE_4096;

     }

     

@@ -176,6 +177,16 @@ void ADS1115_WE::setAutoRange(){
     setVoltageRange_mV(optRange); 

 }

 

+void ADS1115_WE::setPermanentAutoRangeMode(bool autoMode){

+    if(autoMode){

+        autoRangeMode = true;

+    }

+    else{

+        autoRangeMode = false;

+    }

+}

+        

+

 void ADS1115_WE::delayAccToRate(convRate cr){

     switch(cr){

         case ADS1115_8_SPS:

@@ -237,31 +248,41 @@ void ADS1115_WE::startSingleMeasurement(){
 }

     

 float ADS1115_WE::getResult_V(){

-    int16_t rawResult = readRegister(ADS1115_CONV_REG);

+    int16_t rawResult = getRawResult();

     float result = (rawResult * 1.0 / ADS1115_REG_FACTOR) * voltageRange/1000;

     return result;  

 }

 

 float ADS1115_WE::getResult_mV(){

-    int16_t rawResult = readRegister(ADS1115_CONV_REG);

+    int16_t rawResult = getRawResult();

     float result = (rawResult * 1.0 / ADS1115_REG_FACTOR) * voltageRange;

     return result;

 }

 

 int16_t ADS1115_WE::getRawResult(){

     int16_t rawResult = readRegister(ADS1115_CONV_REG);

+    if(autoRangeMode){

+        if((abs(rawResult) > 26214) && (voltageRange != 6144)){ // 80%

+            setAutoRange();

+            rawResult = readRegister(ADS1115_CONV_REG);

+        }

+        else if((abs(rawResult) < 9800) && (voltageRange != 256)){ //30%

+            setAutoRange();

+            rawResult = readRegister(ADS1115_CONV_REG);

+        }

+    }

     return rawResult;

 }

 

 int16_t ADS1115_WE::getResultWithRange(int16_t min, int16_t max){

-    int16_t rawResult = readRegister(ADS1115_CONV_REG);

+    int16_t rawResult = getRawResult();

     int16_t result = 0;

     result = map(rawResult, -32767, 32767, min, max);

     return result;

 }

 

 int16_t ADS1115_WE::getResultWithRange(int16_t min, int16_t max, int16_t maxMillivolt){

-    int16_t rawResult = readRegister(ADS1115_CONV_REG);

+    int16_t rawResult = getRawResult();

     int16_t result = 0;

     result = map(rawResult, -32767, 32767, min, max);

     result = (int16_t) ((1.0 * result * voltageRange / maxMillivolt) + 0.5);

diff --git a/src/ADS1115_WE.h b/src/ADS1115_WE.h
index 395d4d0..3af248b 100644
--- a/src/ADS1115_WE.h
+++ b/src/ADS1115_WE.h
@@ -200,6 +200,12 @@ public:
      * You should ony use it in case you expect stable or slowly changing voltages. 
      */
     void setAutoRange();
+    
+    /* Set the automatic voltage range permanantly, but the range will only be changed if the 
+     * measured value is outside 30 - 80% of the maximum value of the current range. 
+     * Therefore this method is faster than setAutoRange(). 
+     */
+    void setPermanentAutoRangeMode(bool autoMode);
 
     /* Set the inputs to be compared
      *
@@ -263,6 +269,7 @@ private:
     uint16_t voltageRange;
     ADS1115_MEASURE_MODE deviceMeasureMode;
     int i2cAddress;
+    bool autoRangeMode;
     void delayAccToRate(convRate cr);
     int16_t calcLimit(float rawLimit);
     uint8_t writeRegister(uint8_t reg, uint16_t val);