nicla-system: Remove NTC toggling from charge function.

Author: sebromero

libraries/Nicla_System/src/Nicla_System.cpp

@@ -100,7 +100,7 @@ bool nicla::enterShipMode()
   _pmic.writeByte(BQ25120A_ADDRESS, BQ25120A_STATUS, status_reg);
 }
 
-bool nicla::enableCharging(uint16_t mA, bool disableNtc)
+bool nicla::enableCharging(uint16_t mA)
 {
   /*
   The ICHRG is calculated using the following equation: 
@@ -140,13 +140,6 @@ bool nicla::enableCharging(uint16_t mA, bool disableNtc)
   // Also sets the input current limit to 350mA.
   _pmic.writeByte(BQ25120A_ADDRESS, BQ25120A_ILIM_UVLO_CTRL, 0x3F);
 
-  _ntcEnabled = !disableNtc;
-  if (!_ntcEnabled) {
-    // Disable Temperature Sense (B7 = 0) and interrupt on charge status change (B3 = 0).
-    // INT only shows faults and does not show charge status)
-    _pmic.writeByte(BQ25120A_ADDRESS, BQ25120A_TS_CONTROL, 0);
-  }
-
   return _pmic.getFastChargeControlRegister() == _fastChargeRegisterData;
 }
 
@@ -168,7 +161,23 @@ uint8_t nicla::getBatteryFaults() {
 }
 
 void nicla::setBatteryNTCEnabled(bool enabled){
-  _ntcEnabled = enabled;
+  if (_ntcEnabled != enabled) {
+    _ntcEnabled = enabled;
+
+    // Read the current TS_CONTROL register value
+    uint8_t tsControlRegister = _pmic.readByte(BQ25120A_ADDRESS, BQ25120A_TS_CONTROL);
+
+    if (_ntcEnabled) {
+      // Set bit 7 and bit 3 to 1 to enable temperature sense and interrupt on charge status change.
+      tsControlRegister |= 0b10001000;
+    } else {
+      // Set bit 7 and bit 3 to 0 to disable temperature sense and interrupt on charge status change.
+      // INT only shows faults and does not show charge status.
+      tsControlRegister &= 0b01110111;
+    }
+
+    _pmic.writeByte(BQ25120A_ADDRESS, BQ25120A_TS_CONTROL, tsControlRegister);
+  }
 }
 
 float nicla::getRegulatedBatteryVoltage(){

libraries/Nicla_System/src/Nicla_System.h

@@ -81,10 +81,11 @@ class nicla {
    * A safe default charging current value that works for most common LiPo batteries is 0.5C, which means charging at a rate equal to half of the battery's capacity.
    * For example, a 200mAh battery could be charged at 100mA (0.1A).
    * This charging rate is generally safe for most LiPo batteries and provides a good balance between charging speed and battery longevity.
-   * @param disableNtc Whether to disable Temperature Sense and interrupt on charge. The default is true.
+   * @note Make sure to call setBatteryNTCEnabled(false) if your battery does not have an NTC thermistor.
+   * Otherwise the charging will be disabled due to the NTC thermistor not being connected.
    * @return true If the fast charging is enabled successfully. False, otherwise.   
    */
-  static bool enableCharging(uint16_t mA = 20, bool disableNtc = true);
+  static bool enableCharging(uint16_t mA = 20);
 
   /**
    * @brief Disables charging of the battery. It can be resumed by calling enableCharging().
@@ -101,11 +102,12 @@ class nicla {
   static bool runsOnBattery();
 
   /**
-   * @brief Enables or disables the negative temperature coefficient (NTC) thermistor.
+   * @brief Enables or disables the negative temperature coefficient (NTC) thermistor. It is enabled by default.
    * NTCs are used to prevent the batteries from being charged at temperatures that are too high or too low.
    * Set to disabled for standard LiPo batteries without NTC.
    * If your battery has only a plus and minus wire, it does not have an NTC.
-   * The default is enabled.
+   * @note Disabling the NTC will also disable the on-charge-state-change interrupt.
+   * @param enabled Whether to enabled the NTC.
    */
   static void setBatteryNTCEnabled(bool enabled);
 
@@ -186,7 +188,8 @@ class nicla {
 
   /**
    * @brief Get the current operating status of the PMIC.
-   * 
+   * @note If it doesn't report 'Charging' even though you enabled charging with enableCharging(),
+   * you may need to disable the NTC thermistor with setBatteryNTCEnabled(false) in case your battery doesn't have one.
    * @return OperatingStatus One of the following: Ready, Charging, ChargingComplete, Error.
    */
   static OperatingStatus getOperatingStatus();