Merge pull request #1413 from entr0p1/powermgt-nrf52840-v2

nRF52840 Power Management v2 Phase 1 - LPCOMP Wake and startup lockout

variants/heltec_t114/T114Board.cpp

@@ -3,6 +3,35 @@
 #include <Arduino.h>
 #include <Wire.h>
 
+#ifdef NRF52_POWER_MANAGEMENT
+// Static configuration for power management
+// Values come from variant.h defines
+const PowerMgtConfig power_config = {
+  .lpcomp_ain_channel = PWRMGT_LPCOMP_AIN,
+  .lpcomp_refsel = PWRMGT_LPCOMP_REFSEL,
+  .voltage_bootlock = PWRMGT_VOLTAGE_BOOTLOCK
+};
+
+void T114Board::initiateShutdown(uint8_t reason) {
+#if ENV_INCLUDE_GPS == 1
+  pinMode(GPS_EN, OUTPUT);
+  digitalWrite(GPS_EN, LOW);
+#endif
+  digitalWrite(SX126X_POWER_EN, LOW);
+
+  bool enable_lpcomp = (reason == SHUTDOWN_REASON_LOW_VOLTAGE ||
+                        reason == SHUTDOWN_REASON_BOOT_PROTECT);
+  pinMode(PIN_BAT_CTL, OUTPUT);
+  digitalWrite(PIN_BAT_CTL, enable_lpcomp ? HIGH : LOW);
+
+  if (enable_lpcomp) {
+    configureVoltageWake(power_config.lpcomp_ain_channel, power_config.lpcomp_refsel);
+  }
+
+  enterSystemOff(reason);
+}
+#endif // NRF52_POWER_MANAGEMENT
+
 void T114Board::begin() {
   NRF52Board::begin();
   NRF_POWER->DCDCEN = 1;
@@ -21,6 +50,11 @@ void T114Board::begin() {
 #endif
 
   pinMode(SX126X_POWER_EN, OUTPUT);
+#ifdef NRF52_POWER_MANAGEMENT
+  // Boot voltage protection check (may not return if voltage too low)
+  // We need to call this after we configure SX126X_POWER_EN as output but before we pull high
+  checkBootVoltage(&power_config);
+#endif
   digitalWrite(SX126X_POWER_EN, HIGH);
   delay(10); // give sx1262 some time to power up
 }

variants/heltec_t114/T114Board.h

@@ -10,6 +10,11 @@
 #define  MV_LSB   (3000.0F / 4096.0F) // 12-bit ADC with 3.0V input range
 
 class T114Board : public NRF52BoardOTA {
+protected:
+#ifdef NRF52_POWER_MANAGEMENT
+  void initiateShutdown(uint8_t reason) override;
+#endif
+
 public:
     T114Board() : NRF52BoardOTA("T114_OTA") {}
   void begin();
@@ -42,13 +47,13 @@ public:
   }
 
   void powerOff() override {
-    #ifdef LED_PIN
+#ifdef LED_PIN
     digitalWrite(LED_PIN, HIGH);
-    #endif
-    #if ENV_INCLUDE_GPS == 1
+#endif
+#if ENV_INCLUDE_GPS == 1
     pinMode(GPS_EN, OUTPUT);
     digitalWrite(GPS_EN, LOW);
-    #endif
+#endif
     sd_power_system_off();
   }
 };

variants/heltec_t114/platformio.ini

@@ -11,6 +11,7 @@ build_flags = ${nrf52_base.build_flags}
   -I variants/heltec_t114
   -I src/helpers/ui
   -D HELTEC_T114
+  -D NRF52_POWER_MANAGEMENT
   -D P_LORA_DIO_1=20
   -D P_LORA_NSS=24
   -D P_LORA_RESET=25

variants/heltec_t114/variant.h

@@ -30,6 +30,14 @@
 
 #define AREF_VOLTAGE            (3.0)
 
+// Power management boot protection threshold (millivolts)
+// Set to 0 to disable boot protection
+#define PWRMGT_VOLTAGE_BOOTLOCK 3300   // Won't boot below this voltage (mV)
+// LPCOMP wake configuration (voltage recovery from SYSTEMOFF)
+// AIN2 = P0.04 = BATTERY_PIN / PIN_VBAT_READ
+#define PWRMGT_LPCOMP_AIN 2
+#define PWRMGT_LPCOMP_REFSEL 1  // 2/8 VDD (~3.68-4.04V)
+
 ////////////////////////////////////////////////////////////////////////////////
 // Number of pins