Merge pull request #94 from JonNelson/abstract-and-expose-getfsrange

Abstract and expose `getFsRange()`

Author: caternuson

Adafruit_ADS1X15.cpp

@@ -276,39 +276,49 @@ int16_t Adafruit_ADS1X15::getLastConversionResults() {
 
 /**************************************************************************/
 /*!
-    @brief  Compute volts for the given raw counts.
-
-    @param counts the ADC reading in raw counts
+    @brief  Return the current fs range for the configured gain
 
-    @return the ADC reading in volts
+    @return the fsRange for the configured gain, or zero.
+            Zero should not be possible thereby indicating error
 */
 /**************************************************************************/
-float Adafruit_ADS1X15::computeVolts(int16_t counts) {
+float Adafruit_ADS1X15::getFsRange() {
   // see data sheet Table 3
-  float fsRange;
   switch (m_gain) {
   case GAIN_TWOTHIRDS:
-    fsRange = 6.144f;
+    return 6.144f;
     break;
   case GAIN_ONE:
-    fsRange = 4.096f;
+    return 4.096f;
     break;
   case GAIN_TWO:
-    fsRange = 2.048f;
+    return 2.048f;
     break;
   case GAIN_FOUR:
-    fsRange = 1.024f;
+    return 1.024f;
     break;
   case GAIN_EIGHT:
-    fsRange = 0.512f;
+    return 0.512f;
     break;
   case GAIN_SIXTEEN:
-    fsRange = 0.256f;
+    return 0.256f;
     break;
   default:
-    fsRange = 0.0f;
+    return 0.0f;
   }
-  return counts * (fsRange / (32768 >> m_bitShift));
+}
+
+/**************************************************************************/
+/*!
+    @brief  Compute volts for the given raw counts.
+
+    @param counts the ADC reading in raw counts
+
+    @return the ADC reading in volts
+*/
+/**************************************************************************/
+float Adafruit_ADS1X15::computeVolts(int16_t counts) {
+  return counts * (getFsRange() / (32768 >> m_bitShift));
 }
 
 /**************************************************************************/

Adafruit_ADS1X15.h

@@ -66,7 +66,7 @@ constexpr uint16_t MUX_BY_CHANNEL[] = {
     ADS1X15_REG_CONFIG_MUX_SINGLE_1, ///< Single-ended AIN1
     ADS1X15_REG_CONFIG_MUX_SINGLE_2, ///< Single-ended AIN2
     ADS1X15_REG_CONFIG_MUX_SINGLE_3  ///< Single-ended AIN3
-};                                   ///< MUX config by channel
+}; ///< MUX config by channel
 
 #define ADS1X15_REG_CONFIG_PGA_MASK (0x0E00)   ///< PGA Mask
 #define ADS1X15_REG_CONFIG_PGA_6_144V (0x0000) ///< +/-6.144V range = Gain 2/3
@@ -162,6 +162,7 @@ class Adafruit_ADS1X15 {
   int16_t readADC_Differential_2_3();
   void startComparator_SingleEnded(uint8_t channel, int16_t threshold);
   int16_t getLastConversionResults();
+  float getFsRange();
   float computeVolts(int16_t counts);
   void setGain(adsGain_t gain);
   adsGain_t getGain();

keywords.txt

@@ -6,6 +6,7 @@ readADC_Differential_0_1	KEYWORD2
 readADC_Differential_2_3	KEYWORD2
 startComparator_SingleEnded	KEYWORD2
 getLastConversionResults	KEYWORD2
+getFsRange	KEYWORD1
 computeVolts	KEYWORD2
 setGain	KEYWORD2
 getGain	KEYWORD2