merge upstream PR #852: feat: lower CPU freq on idle, add HalPowerManager

lib/hal/HalGPIO.cpp

@@ -1,11 +1,9 @@
 #include <HalGPIO.h>
 #include <SPI.h>
-#include <esp_sleep.h>
 
 void HalGPIO::begin() {
   inputMgr.begin();
   SPI.begin(EPD_SCLK, SPI_MISO, EPD_MOSI, EPD_CS);
-  pinMode(BAT_GPIO0, INPUT);
   pinMode(UART0_RXD, INPUT);
 }
 
@@ -23,23 +21,6 @@ bool HalGPIO::wasAnyReleased() const { return inputMgr.wasAnyReleased(); }
 
 unsigned long HalGPIO::getHeldTime() const { return inputMgr.getHeldTime(); }
 
-void HalGPIO::startDeepSleep() {
-  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
-  while (inputMgr.isPressed(BTN_POWER)) {
-    delay(50);
-    inputMgr.update();
-  }
-  // Arm the wakeup trigger *after* the button is released
-  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
-  // Enter Deep Sleep
-  esp_deep_sleep_start();
-}
-
-int HalGPIO::getBatteryPercentage() const {
-  static const BatteryMonitor battery = BatteryMonitor(BAT_GPIO0);
-  return battery.readPercentage();
-}
-
 bool HalGPIO::isUsbConnected() const {
   // U0RXD/GPIO20 reads HIGH when USB is connected
   return digitalRead(UART0_RXD) == HIGH;

lib/hal/HalGPIO.h

@@ -38,12 +38,6 @@ class HalGPIO {
   bool wasAnyReleased() const;
   unsigned long getHeldTime() const;
 
-  // Setup wake up GPIO and enter deep sleep
-  void startDeepSleep();
-
-  // Get battery percentage (range 0-100)
-  int getBatteryPercentage() const;
-
   // Check if USB is connected
   bool isUsbConnected() const;
 

lib/hal/HalPowerManager.cpp

@@ -0,0 +1,48 @@
+#include "HalPowerManager.h"
+
+#include <esp_sleep.h>
+
+#include "HalGPIO.h"
+
+void HalPowerManager::begin() {
+  pinMode(BAT_GPIO0, INPUT);
+  normalFreq = getCpuFrequencyMhz();
+}
+
+void HalPowerManager::setPowerSaving(bool enabled) {
+  if (normalFreq <= 0) {
+    return;  // invalid state
+  }
+  if (enabled && !isLowPower) {
+    Serial.printf("[%lu] [PWR] Going to low-power mode\n", millis());
+    if (!setCpuFrequencyMhz(LOW_POWER_FREQ)) {
+      Serial.printf("[%lu] [PWR] Failed to set low-power CPU frequency\n", millis());
+      return;
+    }
+  }
+  if (!enabled && isLowPower) {
+    Serial.printf("[%lu] [PWR] Restoring normal CPU frequency\n", millis());
+    if (!setCpuFrequencyMhz(normalFreq)) {
+      Serial.printf("[%lu] [PWR] Failed to restore normal CPU frequency\n", millis());
+      return;
+    }
+  }
+  isLowPower = enabled;
+}
+
+void HalPowerManager::startDeepSleep(HalGPIO& gpio) const {
+  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
+  while (gpio.isPressed(HalGPIO::BTN_POWER)) {
+    delay(50);
+    gpio.update();
+  }
+  // Arm the wakeup trigger *after* the button is released
+  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+  // Enter Deep Sleep
+  esp_deep_sleep_start();
+}
+
+int HalPowerManager::getBatteryPercentage() const {
+  static const BatteryMonitor battery = BatteryMonitor(BAT_GPIO0);
+  return battery.readPercentage();
+}

lib/hal/HalPowerManager.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <Arduino.h>
+#include <BatteryMonitor.h>
+#include <InputManager.h>
+
+#include "HalGPIO.h"
+
+class HalPowerManager {
+  int normalFreq = 0;  // MHz
+  bool isLowPower = false;
+
+ public:
+  static constexpr int LOW_POWER_FREQ = 10;                    // MHz
+  static constexpr unsigned long IDLE_POWER_SAVING_MS = 3000;  // ms
+
+  void begin();
+
+  // Control CPU frequency for power saving
+  void setPowerSaving(bool enabled);
+
+  // Setup wake up GPIO and enter deep sleep
+  void startDeepSleep(HalGPIO& gpio) const;
+
+  // Get battery percentage (range 0-100)
+  int getBatteryPercentage() const;
+};

src/main.cpp

@@ -3,6 +3,7 @@
 #include <GfxRenderer.h>
 #include <HalDisplay.h>
 #include <HalGPIO.h>
+#include <HalPowerManager.h>
 #include <HalStorage.h>
 #include <SPI.h>
 #include <builtinFonts/all.h>
@@ -31,6 +32,7 @@
 
 HalDisplay display;
 HalGPIO gpio;
+HalPowerManager powerManager;
 MappedInputManager mappedInputManager(gpio);
 GfxRenderer renderer(display);
 Activity* currentActivity;
@@ -181,7 +183,7 @@ void verifyPowerButtonDuration() {
   if (abort) {
     // Button released too early. Returning to sleep.
     // IMPORTANT: Re-arm the wakeup trigger before sleeping again
-    gpio.startDeepSleep();
+    powerManager.startDeepSleep(gpio);
   }
 }
 
@@ -204,7 +206,7 @@ void enterDeepSleep() {
   Serial.printf("[%lu] [   ] Power button press calibration value: %lu ms\n", millis(), t2 - t1);
   Serial.printf("[%lu] [   ] Entering deep sleep.\n", millis());
 
-  gpio.startDeepSleep();
+  powerManager.startDeepSleep(gpio);
 }
 
 void onGoHome();
@@ -281,6 +283,7 @@ void setup() {
   t1 = millis();
 
   gpio.begin();
+  powerManager.begin();
 
   // Only start serial if USB connected
   if (gpio.isUsbConnected()) {
@@ -316,7 +319,7 @@ void setup() {
     case HalGPIO::WakeupReason::AfterUSBPower:
       // If USB power caused a cold boot, go back to sleep
       Serial.printf("[%lu] [   ] Wakeup reason: After USB Power\n", millis());
-      gpio.startDeepSleep();
+      powerManager.startDeepSleep(gpio);
       break;
     case HalGPIO::WakeupReason::AfterFlash:
       // After flashing, just proceed to boot
@@ -372,7 +375,8 @@ void loop() {
   // Check for any user activity (button press or release) or active background work
   static unsigned long lastActivityTime = millis();
   if (gpio.wasAnyPressed() || gpio.wasAnyReleased() || (currentActivity && currentActivity->preventAutoSleep())) {
-    lastActivityTime = millis();  // Reset inactivity timer
+    lastActivityTime = millis();         // Reset inactivity timer
+    powerManager.setPowerSaving(false);  // Restore normal CPU frequency on user activity
   }
 
   const unsigned long sleepTimeoutMs = SETTINGS.getSleepTimeoutMs();
@@ -410,9 +414,9 @@ void loop() {
   if (currentActivity && currentActivity->skipLoopDelay()) {
     yield();  // Give FreeRTOS a chance to run tasks, but return immediately
   } else {
-    static constexpr unsigned long IDLE_POWER_SAVING_MS = 3000;  // 3 seconds
-    if (millis() - lastActivityTime >= IDLE_POWER_SAVING_MS) {
+    if (millis() - lastActivityTime >= HalPowerManager::IDLE_POWER_SAVING_MS) {
       // If we've been inactive for a while, increase the delay to save power
+      powerManager.setPowerSaving(true);  // Lower CPU frequency after extended inactivity
       delay(50);
     } else {
       // Short delay to prevent tight loop while still being responsive