Wio Tracker L1: Improve battery reading and add power management

variants/wio-tracker-l1/WioTrackerL1Board.cpp

@@ -3,19 +3,53 @@
 
 #include "WioTrackerL1Board.h"
 
+#ifdef NRF52_POWER_MANAGEMENT
+// Static configuration for power management
+// Values set in variant.h defines
+const PowerMgtConfig power_config = {
+  .lpcomp_ain_channel = PWRMGT_LPCOMP_AIN,
+  .lpcomp_refsel = PWRMGT_LPCOMP_REFSEL,
+  .voltage_bootlock = PWRMGT_VOLTAGE_BOOTLOCK
+};
+
+void WioTrackerL1Board::initiateShutdown(uint8_t reason) {
+  bool enable_lpcomp = (reason == SHUTDOWN_REASON_LOW_VOLTAGE ||
+                        reason == SHUTDOWN_REASON_BOOT_PROTECT);
+
+  pinMode(VBAT_ENABLE, OUTPUT);
+  digitalWrite(VBAT_ENABLE, enable_lpcomp ? LOW : HIGH);
+
+  if (enable_lpcomp) {
+    configureVoltageWake(power_config.lpcomp_ain_channel, power_config.lpcomp_refsel);
+  }
+
+  enterSystemOff(reason);
+}
+#endif // NRF52_POWER_MANAGEMENT
+
 void WioTrackerL1Board::begin() {
   NRF52BoardDCDC::begin();
   btn_prev_state = HIGH;
 
-  pinMode(PIN_VBAT_READ, INPUT); // VBAT ADC input
+  // Configure battery voltage ADC (needed for boot voltage check)
+  pinMode(PIN_VBAT_READ, INPUT);
+  pinMode(VBAT_ENABLE, OUTPUT);
+  digitalWrite(VBAT_ENABLE, HIGH);        // Disable VBAT divider to save power
+  analogReadResolution(12);
+  analogReference(AR_INTERNAL);
+
+#ifdef NRF52_POWER_MANAGEMENT
+  // Boot voltage protection check (may not return if voltage too low)
+  checkBootVoltage(&power_config);
+#endif
+
   // Set all button pins to INPUT_PULLUP
   pinMode(PIN_BUTTON1, INPUT_PULLUP);
   pinMode(PIN_BUTTON2, INPUT_PULLUP);
   pinMode(PIN_BUTTON3, INPUT_PULLUP);
   pinMode(PIN_BUTTON4, INPUT_PULLUP);
   pinMode(PIN_BUTTON5, INPUT_PULLUP);
   pinMode(PIN_BUTTON6, INPUT_PULLUP);
-
 
   #if defined(PIN_WIRE_SDA) && defined(PIN_WIRE_SCL)
     Wire.setPins(PIN_WIRE_SDA, PIN_WIRE_SCL);
@@ -30,3 +64,18 @@ void WioTrackerL1Board::begin() {
 
   delay(10);   // give sx1262 some time to power up
 }
+
+uint16_t WioTrackerL1Board::getBattMilliVolts() {
+  digitalWrite(VBAT_ENABLE, LOW);         // Enable VBAT divider
+  delayMicroseconds(100);                 // Allow voltage divider to settle
+
+  // Average multiple samples to reduce noise
+  uint32_t raw = 0;
+  for (int i = 0; i < 8; i++) {
+    raw += analogRead(PIN_VBAT_READ);
+  }
+  raw = raw / 8;
+
+  digitalWrite(VBAT_ENABLE, HIGH);        // Disable divider to save power
+  return (raw * ADC_MULTIPLIER * AREF_VOLTAGE) / 4.096;
+}

variants/wio-tracker-l1/WioTrackerL1Board.h

@@ -8,6 +8,10 @@ class WioTrackerL1Board : public NRF52BoardDCDC {
 protected:
   uint8_t btn_prev_state;
 
+#ifdef NRF52_POWER_MANAGEMENT
+  void initiateShutdown(uint8_t reason) override;
+#endif
+
 public:
   WioTrackerL1Board() : NRF52Board("WioTrackerL1 OTA") {}
   void begin();
@@ -21,14 +25,7 @@ class WioTrackerL1Board : public NRF52BoardDCDC {
   }
 #endif
 
-  uint16_t getBattMilliVolts() override {
-    int adcvalue = 0;
-    analogReadResolution(12);
-    analogReference(AR_INTERNAL);
-    delay(10);
-    adcvalue = analogRead(PIN_VBAT_READ);
-    return (adcvalue * ADC_MULTIPLIER * AREF_VOLTAGE) / 4.096;
-  }
+  uint16_t getBattMilliVolts() override;
 
   const char* getManufacturerName() const override {
     return "Seeed Wio Tracker L1";

variants/wio-tracker-l1/platformio.ini

@@ -8,6 +8,7 @@ build_flags = ${nrf52_base.build_flags}
   -I lib/nrf52/s140_nrf52_7.3.0_API/include/nrf52
   -I variants/wio-tracker-l1
   -D WIO_TRACKER_L1
+  -D NRF52_POWER_MANAGEMENT
   -D RADIO_CLASS=CustomSX1262
   -D WRAPPER_CLASS=CustomSX1262Wrapper
   -D LORA_TX_POWER=22

variants/wio-tracker-l1/variant.h

@@ -50,6 +50,15 @@
 #define ADC_MULTIPLIER          (2.0F)
 #define ADC_RESOLUTION          (12)
 
+// Power management boot protection threshold (millivolts)
+// Set to 0 to disable boot protection
+#define PWRMGT_VOLTAGE_BOOTLOCK    3300   // Won't boot below this voltage
+
+// LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
+#define PWRMGT_LPCOMP_AIN           7     // AIN7 = P0.31 = PIN_VBAT_READ
+// Wake when battery voltage recovers to ~3.7V
+#define PWRMGT_LPCOMP_REFSEL        12    // 9/16 VDD
+
 // Serial interfaces
 #define PIN_SERIAL1_RX          (7)
 #define PIN_SERIAL1_TX          (6)