Adding the ability to clear each status flag after reading

Author: PaulZC

src/SparkFun_MAX1704x_Fuel_Gauge_Arduino_Library.cpp

@@ -266,35 +266,81 @@ uint8_t SFE_MAX1704X::getStatus(void)
   return (statusReg & 0x7F); //Highest bit is don't care
 }
 
-bool SFE_MAX1704X::isReset(void)
+bool SFE_MAX1704X::isReset(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_RI);
+  bool flag = (status & MAX1704x_STATUS_RI) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_RI << 8);
+  }
+  return (flag);
 }
-bool SFE_MAX1704X::isVoltageHigh(void)
+bool SFE_MAX1704X::isVoltageHigh(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_VH);
+  bool flag = (status & MAX1704x_STATUS_VH) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_VH << 8);
+  }
+  return (flag);
 }
-bool SFE_MAX1704X::isVoltageLow(void)
+bool SFE_MAX1704X::isVoltageLow(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_VL);
+  bool flag = (status & MAX1704x_STATUS_VL) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_VL << 8);
+  }
+  return (flag);
 }
-bool SFE_MAX1704X::isVoltageReset(void)
+bool SFE_MAX1704X::isVoltageReset(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_VR);
+  bool flag = (status & MAX1704x_STATUS_VR) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_VR << 8);
+  }
+  return (flag);
 }
-bool SFE_MAX1704X::isLow(void)
+bool SFE_MAX1704X::isLow(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_HD);
+  bool flag = (status & MAX1704x_STATUS_HD) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_HD << 8);
+  }
+  return (flag);
 }
-bool SFE_MAX1704X::isChange(void)
+bool SFE_MAX1704X::isChange(bool clear)
 {
   uint8_t status = getStatus();
-  return (status & MAX1704x_STATUS_SC);
+  bool flag = (status & MAX1704x_STATUS_SC) > 0;
+  if (flag && clear) // Clear the flag if requested
+  {
+    // Clear the aligned bit in the status register
+    clearStatusRegBits(MAX1704x_STATUS_SC << 8);
+  }
+  return (flag);
+}
+
+// Clear the specified bit in the MAX17048/49 status register (PRIVATE)
+// This requires the bits in mask to be correctly aligned.
+// MAX1704x_STATUS_RI etc. will need to be shifted left by 8 bits to become aligned.
+uint8_t SFE_MAX1704X::clearStatusRegBits(uint16_t mask)
+{
+  uint16_t statusReg = read16(MAX17048_STATUS);
+  statusReg &= ~mask; // Clear the specified bits
+  return (write16(statusReg, MAX17048_STATUS)); // Write the contents back again
 }
 
 uint8_t SFE_MAX1704X::clearAlert()

src/SparkFun_MAX1704x_Fuel_Gauge_Arduino_Library.h

@@ -87,7 +87,7 @@ typedef enum {
 #define MAX1704x_STATUS_VR (1 << 3) // Assumes the MSB has been shifted >> 8
 #define MAX1704x_STATUS_HD (1 << 4) // Assumes the MSB has been shifted >> 8
 #define MAX1704x_STATUS_SC (1 << 5) // Assumes the MSB has been shifted >> 8
-#define MAX1704x_STATUS_EnVR (1 << 14)
+#define MAX1704x_STATUS_EnVR (1 << 14) // ** Unshifted **
 
 ////////////////////////////////////////
 // MAX17043 Command Register Commands //
@@ -160,9 +160,9 @@ class SFE_MAX1704X
   // setThreshold([percent]) - Set the MAX17043's percentage threshold that will
   // trigger an alert.
   // Input: [percent] - Percentage value that will trigger an alert interrupt.
-  // Any value between 1 and 32 is valid.
+  // Any value between 1 and 32 is valid. Default value is 0x1C == 4%
   // Output: 0 on success, positive integer on fail.
-  uint8_t setThreshold(uint8_t percent);
+  uint8_t setThreshold(uint8_t percent = 4);
 
   // sleep() - Set the MAX17043 into sleep mode.
   // Output: 0 on success, positive integer on fail.
@@ -257,12 +257,14 @@ class SFE_MAX1704X
   uint8_t getStatus();
 
   //(MAX17048/49) Various helper functions to check bits in status register
-  bool isReset();       //True after POR
-  bool isVoltageHigh(); //True when VCELL is above VALRTMAX (see setAlertMinVoltage)
-  bool isVoltageLow();
-  bool isVoltageReset();
-  bool isLow();    //True when SOC crosses the value in ATHD (see setThreshold)
-  bool isChange(); //True when SOC changes by at least 1%
+  // INPUT: [clear] - If [clear] is true, the alert flag will be cleared if it
+  // was set.
+  bool isReset(bool clear = false);       //True after POR
+  bool isVoltageHigh(bool clear = false); //True when VCELL is above VALRTMAX (see setAlertMinVoltage)
+  bool isVoltageLow(bool clear = false);
+  bool isVoltageReset(bool clear = false);
+  bool isLow(bool clear = false);    //True when SOC crosses the value in ATHD (see setThreshold)
+  bool isChange(bool clear = false); //True when SOC changes by at least 1% and SOCAlert is enabled
 
   // getAlert([clear]) - Check if the MAX1704X's ALRT alert interrupt has been
   // triggered.
@@ -367,6 +369,12 @@ class SFE_MAX1704X
   Stream *_debugPort;          //The stream to send debug messages to if enabled. Usually Serial.
   boolean _printDebug = false; //Flag to print debugging variables
 
+  // Clear the specified bit(s) in the MAX17048/49 status register
+  // This requires the bits in mask to be correctly aligned.
+  // MAX1704x_STATUS_RI etc. will need to be shifted left by 8 bits to become aligned.
+  // Output: 0 on success, positive integer on fail.
+  uint8_t clearStatusRegBits(uint16_t mask);
+
   int _device = MAX1704X_MAX17043; // Default to MAX17043
   float _full_scale = 5.12; // Default: full-scale for the MAX17043
 };