rak4631: implement button power-off and fix immediate wakeup (closes #1411)

variants/rak4631/RAK4631Board.cpp

@@ -4,6 +4,10 @@
 
 #include "RAK4631Board.h"
 
+#if __has_include(<bluefruit.h>)
+#include <bluefruit.h>
+#endif
+
 #ifdef ETHERNET_ENABLED
 // Drive WB_IO2 HIGH as early as possible using direct register access.
 // WB_IO2 (P1.02, Arduino pin 34) controls the WisBlock slot power switch.
@@ -25,31 +29,182 @@ const PowerMgtConfig power_config = {
   .voltage_bootlock = PWRMGT_VOLTAGE_BOOTLOCK
 };
 
+#if defined(PIN_USER_BTN_ANA) && (PIN_USER_BTN_ANA >= 0)
+  #define BOARD_BUTTON_PIN PIN_USER_BTN_ANA
+#elif defined(WB_A1)
+  #define BOARD_BUTTON_PIN WB_A1
+#elif defined(PIN_USER_BTN) && (PIN_USER_BTN >= 0)
+  #define BOARD_BUTTON_PIN PIN_USER_BTN
+#endif
+
+static bool isButtonPressed() {
+#if defined(PIN_USER_BTN_ANA) && (PIN_USER_BTN_ANA >= 0)
+  return analogRead(PIN_USER_BTN_ANA) < 20;
+#elif defined(BOARD_BUTTON_PIN)
+  return digitalRead(BOARD_BUTTON_PIN) == LOW;
+#else
+  return false;
+#endif
+}
+
+void RAK4631Board::powerOff() {
+#if defined(BOARD_BUTTON_PIN)
+  // Turn on LED to indicate long press was recognized and signal to release
+  #if defined(PIN_LED1)
+  digitalWrite(PIN_LED1, HIGH);
+  #elif defined(PIN_LED2)
+  digitalWrite(PIN_LED2, HIGH);
+  #endif
+
+  // Wait until the user physically releases the button and it remains stably released
+  uint32_t stable_start = millis();
+  while (millis() - stable_start < 100) {
+    if (isButtonPressed()) {
+      stable_start = millis();
+    }
+    delay(5);
+  }
+
+  // Turn off LEDs before shutdown
+  #if defined(PIN_LED1)
+  digitalWrite(PIN_LED1, LOW);
+  #endif
+  #if defined(PIN_LED2)
+  digitalWrite(PIN_LED2, LOW);
+  #endif
+#endif
+
+#ifdef NRF52_POWER_MANAGEMENT
+  initiateShutdown(SHUTDOWN_REASON_USER);
+#else
+  NRF52BoardDCDC::powerOff();
+#endif
+}
+
 void RAK4631Board::initiateShutdown(uint8_t reason) {
+#if __has_include(<bluefruit.h>)
+  uint8_t sd_enabled = 0;
+  sd_softdevice_is_enabled(&sd_enabled);
+  if (sd_enabled) {
+    Bluefruit.autoConnLed(false);
+    uint16_t conn_hdl = Bluefruit.connHandle();
+    if (conn_hdl != BLE_CONN_HANDLE_INVALID) {
+      Bluefruit.disconnect(conn_hdl);
+      delay(50);
+    }
+    Bluefruit.Advertising.stop();
+  }
+#endif
+
+  // Disconnect LoRa pins and detach RadioLib interrupts before powering down
+  // Otherwise, the collapsing power rail on the SX1262 triggers a false DETECT wakeup
+  detachInterrupt(digitalPinToInterrupt(P_LORA_DIO_1));
+#ifdef P_LORA_BUSY
+  detachInterrupt(digitalPinToInterrupt(P_LORA_BUSY));
+  nrf_gpio_cfg_default(g_ADigitalPinMap[P_LORA_BUSY]);
+#endif
+#ifdef P_LORA_RESET
+  nrf_gpio_cfg_default(g_ADigitalPinMap[P_LORA_RESET]);
+#endif
+#ifdef P_LORA_NSS
+  nrf_gpio_cfg_default(g_ADigitalPinMap[P_LORA_NSS]);
+#endif
+  nrf_gpio_cfg_default(g_ADigitalPinMap[P_LORA_DIO_1]);
+
   // Disable LoRa module power before shutdown
   digitalWrite(SX126X_POWER_EN, LOW);
 
+#if defined(BOARD_BUTTON_PIN)
+  // Ensure pullup is engaged and line is stably HIGH before arming SENSE
+  pinMode(BOARD_BUTTON_PIN, INPUT_PULLUP);
+  uint32_t settle_start = millis();
+  while (millis() - settle_start < 50) {
+    if (digitalRead(BOARD_BUTTON_PIN) == LOW) {
+      settle_start = millis();
+    }
+    delay(5);
+  }
+
+  // Ensure no other pin has SENSE enabled
+  for (uint32_t p = 0; p < 32; p++) {
+    if (p != g_ADigitalPinMap[BOARD_BUTTON_PIN]) {
+      nrf_gpio_cfg_sense_set(p, NRF_GPIO_PIN_NOSENSE);
+    }
+  }
+#if defined(NRF_P1)
+  for (uint32_t p = 32; p < 48; p++) {
+    if (p != g_ADigitalPinMap[BOARD_BUTTON_PIN]) {
+      nrf_gpio_cfg_sense_set(p, NRF_GPIO_PIN_NOSENSE);
+    }
+  }
+#endif
+
+  nrf_gpio_cfg_sense_input(g_ADigitalPinMap[BOARD_BUTTON_PIN], NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);
+#endif
+
   if (reason == SHUTDOWN_REASON_LOW_VOLTAGE ||
       reason == SHUTDOWN_REASON_BOOT_PROTECT) {
     configureVoltageWake(power_config.lpcomp_ain_channel, power_config.lpcomp_refsel);
   }
 
-  enterSystemOff(reason);
+  // Record shutdown reason in GPREGRET2
+  uint8_t sd_on = 0;
+  sd_softdevice_is_enabled(&sd_on);
+  if (sd_on) {
+    sd_power_gpregret_clr(1, 0xFF);
+    sd_power_gpregret_set(1, reason);
+  } else {
+    NRF_POWER->GPREGRET2 = reason;
+  }
+
+  Serial.flush();
+  delay(50);
+
+  // Ensure all LEDs are explicitly powered off and disconnected right before entering sleep
+#if defined(PIN_LED1)
+  digitalWrite(PIN_LED1, LOW);
+  pinMode(PIN_LED1, INPUT);
+  nrf_gpio_pin_clear(g_ADigitalPinMap[PIN_LED1]);
+  nrf_gpio_cfg_default(g_ADigitalPinMap[PIN_LED1]);
+#endif
+#if defined(PIN_LED2)
+  digitalWrite(PIN_LED2, LOW);
+  pinMode(PIN_LED2, INPUT);
+  nrf_gpio_pin_clear(g_ADigitalPinMap[PIN_LED2]);
+  nrf_gpio_cfg_default(g_ADigitalPinMap[PIN_LED2]);
+#endif
+
+#if defined(BOARD_BUTTON_PIN)
+  // Ensure the button is unpressed before clearing latch
+  while (digitalRead(BOARD_BUTTON_PIN) == LOW) {
+    delay(10);
+  }
+#endif
+
+  // Clear any latched GPIO DETECT events right before sleep
+  NRF_P0->LATCH = 0xFFFFFFFF;
+#if defined(NRF_P1)
+  NRF_P1->LATCH = 0xFFFFFFFF;
+#endif
+
+  if (sd_on) {
+    sd_power_system_off();
+  }
+  // Force hardware system off directly
+  NRF_POWER->SYSTEMOFF = POWER_SYSTEMOFF_SYSTEMOFF_Enter;
+  while (1) {
+    NRF_POWER->SYSTEMOFF = POWER_SYSTEMOFF_SYSTEMOFF_Enter;
+  }
 }
 #endif // NRF52_POWER_MANAGEMENT
 
 void RAK4631Board::begin() {
   NRF52BoardDCDC::begin();
   pinMode(PIN_VBAT_READ, INPUT);
-#ifdef PIN_USER_BTN
-  pinMode(PIN_USER_BTN, INPUT_PULLUP);
-#endif
-
-#ifdef PIN_USER_BTN_ANA
-  pinMode(PIN_USER_BTN_ANA, INPUT_PULLUP);
+#if defined(BOARD_BUTTON_PIN)
+  pinMode(BOARD_BUTTON_PIN, INPUT_PULLUP);
 #endif
 
-
 #if defined(PIN_BOARD_SDA) && defined(PIN_BOARD_SCL)
   Wire.setPins(PIN_BOARD_SDA, PIN_BOARD_SCL);
 #endif
@@ -64,4 +219,20 @@ void RAK4631Board::begin() {
 #endif
   digitalWrite(SX126X_POWER_EN, HIGH);
   delay(10);   // give sx1262 some time to power up
+}
+
+void RAK4631Board::loop() {
+  NRF52BoardDCDC::loop();
+
+#if defined(BOARD_BUTTON_PIN)
+  if (isButtonPressed()) {
+    if (btn_press_start == 0) {
+      btn_press_start = millis();
+    } else if (millis() - btn_press_start >= 3000) {
+      powerOff();
+    }
+  } else {
+    btn_press_start = 0;
+  }
+#endif
 }

variants/rak4631/RAK4631Board.h

@@ -10,13 +10,15 @@
 
 class RAK4631Board : public NRF52BoardDCDC {
 protected:
+  uint32_t btn_press_start = 0;
 #ifdef NRF52_POWER_MANAGEMENT
   void initiateShutdown(uint8_t reason) override;
 #endif
 
 public:
   RAK4631Board() : NRF52Board("RAK4631_OTA") {}
   void begin();
+  void loop() override;
 
   #define BATTERY_SAMPLES 8
 
@@ -35,4 +37,6 @@ class RAK4631Board : public NRF52BoardDCDC {
   const char* getManufacturerName() const override {
     return "RAK 4631";
   }
+
+  void powerOff() override;
 };

variants/rak4631/variant.h

@@ -104,6 +104,7 @@ extern "C"
 	static const uint8_t A7 = PIN_A7;
 #define ADC_RESOLUTION 14
 
+#define NRF52_POWER_MANAGEMENT
 // 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)