- power on/off (deep sleep) using long presses

- battery stats via 18650CL library
2026-04-29 10:24:26 -07:00 · 2025-11-20 22:35:17 -08:00
parent 62d377cd87
commit 0344240876
3 changed files with 150 additions and 5 deletions
@@ -46,6 +46,11 @@ Before flashing custom firmware, back up the factory firmware:
 # Read entire 16MB flash
 esptool.py --chip esp32c3 --port COM5 read_flash 0x0 0x1000000 firmware_backup.bin
 ```
+```powershell
+# Read only app0 (faster)
+esptool.py --chip esp32c3 --port COM5 read_flash 0x10000 0x640000 app0_backup.bin
+```
+

 ### Restore Original Firmware

@@ -56,6 +61,11 @@ To restore the backed-up firmware:
 esptool.py --chip esp32c3 --port COM5 write_flash 0x0 firmware_backup.bin
 ```

+```powershell
+# Write back only app0 (faster)
+esptool.py --chip esp32c3 --port COM5 write_flash 0x10000 app0_backup.bin
+```
+
 **Important**: Make sure to use the correct COM port for your device.

 ## Notes
@@ -69,7 +79,7 @@ esptool.py --chip esp32c3 --port COM5 write_flash 0x0 firmware_backup.bin
 - Better font rendering with grayscale support
 - ~~Power on/off~~
 - SD card reader
- Read battery percentage
+- ~~Read battery percentage~~
 - WiFi
 - Bluetooth

@@ -91,6 +101,13 @@ The XteinkX4 uses **resistor ladder networks** connected to two ADC pins for but

 **GPIO3 (Power button)**:
 - Pressed: ~3
+- This example uses a 2-second-long press for sleep and a 1.5-second-long press to wake from sleep
+
+**Battery ADC**:
+- GPIO0, raw value ranges up to ~2800 when charging. ~2760 when not charging and full.
+- Voltage divider is ~2 (2 x 10K resistors), `CONV_FACTOR=1.6113` for [this library](https://github.com/pangodream/18650CL)
+- [See here](https://www.pangodream.es/esp32-getting-battery-charging-level) for details how voltage and charge level are calculated
+- `CONV_FACTOR` may need calibration depending on the device, `1.5176` working well on mine

 ### Implementation Notes

@@ -16,6 +16,7 @@ board_build.partitions = default_16MB.csv
 ; Libraries
 lib_deps =
    zinggjm/GxEPD2@^1.5.9
+    https://github.com/pangodream/18650CL

 ; Build flags
 build_flags = 
@@ -4,6 +4,7 @@
 #include <GxEPD2_BW.h>
 #include <SPI.h>
 #include "image.h"
+#include "Pangodream_18650_CL.h"

 // Display SPI pins (custom pins for XteinkX4, not hardware SPI defaults)
 #define EPD_SCLK 8  // SPI Clock
@@ -17,6 +18,16 @@
 #define BTN_GPIO1 1 // 4 buttons: Back, Confirm, Left, Right
 #define BTN_GPIO2 2 // 2 buttons: Volume Up, Volume Down
 #define BTN_GPIO3 3 // Power button
+#define BAT_GPIO  0 // Battery voltage
+
+#define ADC_PIN 0
+#define CONV_FACTOR 1.5176
+#define READS 10
+#define CHARGER_THRESHOLD 2770
+
+Pangodream_18650_CL BL(ADC_PIN, CONV_FACTOR, READS);
+
+static int rawBat = 0;

 // Button enum
 enum Button
@@ -37,6 +48,7 @@ enum DisplayCommand
  DISPLAY_NONE = 0,
  DISPLAY_HEADER,
  DISPLAY_TEXT,
+  DISPLAY_SLEEP,
  TOGGLE_IMAGE
 };

@@ -87,7 +99,7 @@ Button GetPressedButton()
  if (btn3 < BTN_POWER_VAL + BTN_THRESHOLD)
  {
    return POWER;
-  }  
+  }
  // Check BTN_GPIO1 (4 buttons on resistor ladder)
  if (btn1 < BTN_RIGHT_VAL + BTN_THRESHOLD)
  {
@@ -121,7 +133,8 @@ Button GetPressedButton()

 // GxEPD2 display - Using GxEPD2_426_GDEQ0426T82
 // Note: XteinkX4 has 4.26" 800x480 display
-GxEPD2_BW<GxEPD2_426_GDEQ0426T82, GxEPD2_426_GDEQ0426T82::HEIGHT> display(GxEPD2_426_GDEQ0426T82(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY));
+GxEPD2_BW<GxEPD2_426_GDEQ0426T82, GxEPD2_426_GDEQ0426T82::HEIGHT> display(
+  GxEPD2_426_GDEQ0426T82(EPD_CS, EPD_DC, EPD_RST, EPD_BUSY));

 // FreeRTOS task for non-blocking display updates
 TaskHandle_t displayTaskHandle = NULL;
@@ -157,12 +170,14 @@ void displayUpdateTask(void *parameter)
          display.setFont(&FreeMonoBold12pt7b);
          display.setCursor(20, 100);
          display.print(getButtonName(currentPressedButton));
+          display.setCursor(20, 200);
+          display.print(esp_reset_reason());
        } while (display.nextPage());
      }
      else if (cmd == DISPLAY_TEXT)
      {
        // Use partial refresh for text updates
-        display.setPartialWindow(0, 75, display.width(), 150);
+        display.setPartialWindow(0, 75, display.width(), 300);
        display.firstPage();
        do
        {
@@ -170,6 +185,14 @@ void displayUpdateTask(void *parameter)
          display.setFont(&FreeMonoBold12pt7b);
          display.setCursor(20, 100);
          display.print(getButtonName(currentPressedButton));
+          display.setCursor(20, 160);
+          display.printf("Battery: %s", rawBat > CHARGER_THRESHOLD ? "Charging" : "Discharging");
+          display.setCursor(40, 200);
+          display.printf("Raw: %i", rawBat);
+          display.setCursor(40, 240);
+          display.printf("Volts: %.2f", BL.getBatteryVolts());
+          display.setCursor(40, 280);
+          display.printf("Charge level: %i%%", BL.getBatteryChargeLevel());
        } while (display.nextPage());
      }
      else if (cmd == TOGGLE_IMAGE)
@@ -190,6 +213,20 @@ void displayUpdateTask(void *parameter)
          }
        } while (display.nextPage());
      }
+      else if (cmd == DISPLAY_SLEEP)
+      {
+        // Use full window for initial welcome screen with header
+        display.setFullWindow();
+        display.firstPage();
+        do
+        {
+          display.fillScreen(GxEPD_WHITE);
+          // Header font
+          display.setFont(&FreeMonoBold18pt7b);
+          display.setCursor(120, 380);
+          display.print("Sleeping...");
+        } while (display.nextPage());
+      }
    }
    vTaskDelay(10 / portTICK_PERIOD_MS);
  }
@@ -197,6 +234,40 @@ void displayUpdateTask(void *parameter)

 void setup()
 {
+  // Check if boot was triggered by the Power Button (Deep Sleep Wakeup)
+  // If triggered by RST pin or Battery insertion, this will be false, allowing normal boot.
+  if (esp_sleep_get_wakeup_cause() == ESP_SLEEP_WAKEUP_GPIO)
+  {
+    // Woke up from sleep via Power Button. Verifying long press...
+    // Temporarily configure pin as digital input to check state
+    pinMode(BTN_GPIO3, INPUT);
+
+    const unsigned long LONG_PRESS_MS = 1500; // 1.5 seconds required
+    unsigned long pressStart = millis();
+    bool bootConfirmed = true;
+
+    // Monitor button state for the duration
+    while (millis() - pressStart < LONG_PRESS_MS)
+    {
+      // If button reads HIGH (released) before time is up
+      if (digitalRead(BTN_GPIO3) == HIGH)
+      {
+        bootConfirmed = false;
+        break;
+      }
+      delay(10);
+    }
+
+    if (!bootConfirmed)
+    {
+      // Button released too early. Returning to sleep.
+      pinMode(BTN_GPIO3, INPUT_PULLUP);
+      // IMPORTANT: Re-arm the wakeup trigger before sleeping again
+      esp_deep_sleep_enable_gpio_wakeup(1ULL << BTN_GPIO3, ESP_GPIO_WAKEUP_GPIO_LOW);
+      esp_deep_sleep_start();
+    }
+  }
+
  Serial.begin(115200);

  // Wait for serial monitor
@@ -206,14 +277,17 @@ void setup()
    delay(10);
  }

+
  Serial.println("\n=================================");
  Serial.println("  xteink x4 sample");
  Serial.println("=================================");
  Serial.println();

  // Initialize button pins
+  pinMode(BAT_GPIO, INPUT);
  pinMode(BTN_GPIO1, INPUT);
  pinMode(BTN_GPIO2, INPUT);
+  pinMode(BTN_GPIO3, INPUT);

  // Initialize SPI with custom pins
  SPI.begin(EPD_SCLK, -1, EPD_MOSI, EPD_CS);
@@ -257,6 +331,46 @@ void loop()
    Serial.println(getButtonName(currentButton));
    currentPressedButton = currentButton;

+
+    if (currentButton == POWER)
+    {
+      Serial.println("Power button pressed");
+      displayCommand = DISPLAY_TEXT;
+      // 1. Switch pin to Digital Input with Pull-up
+      // This is crucial! 'analogRead' configures the pin as ADC, often disabling the digital input buffer.
+      // If the digital buffer is disabled, the sleep controller reads '0' (LOW) and wakes immediately.
+      // The Pull-up also prevents the pin from floating if the external circuit is open.
+      pinMode(BTN_GPIO3, INPUT_PULLUP);
+
+      // 2. Wait for button release
+      // We wait until the digital state is HIGH (released)
+      unsigned long pressedTime = millis();
+      bool longPress = false;
+      while (digitalRead(BTN_GPIO3) == LOW)
+      {
+        delay(50);
+        if (millis() - pressedTime > 2000)
+        {
+          longPress = true;
+          break;
+        }
+      }
+
+      // Power button long pressed, go to sleep
+      if (longPress)
+      {
+        displayCommand = DISPLAY_SLEEP;
+        Serial.println("Power button released after a long press. Entering deep sleep.");
+        delay(2000); // Allow Serial buffer to empty and display to update
+
+        // 3. Enable Wakeup on LOW
+        esp_deep_sleep_enable_gpio_wakeup(1ULL << BTN_GPIO3, ESP_GPIO_WAKEUP_GPIO_LOW);
+
+        // 4. Enter Deep Sleep
+        esp_deep_sleep_start();
+      }
+    }
+
    if (currentButton == CONFIRM)
    {
      displayCommand = TOGGLE_IMAGE;
@@ -275,6 +389,7 @@ void loop()
  unsigned long now = millis();
  if (now - lastLogMs >= 1000)
  {
+    rawBat =  analogRead(BAT_GPIO);
    int rawBtn1 = analogRead(BTN_GPIO1);
    int rawBtn2 = analogRead(BTN_GPIO2);
    int rawBtn3 = analogRead(BTN_GPIO3);
@@ -283,7 +398,19 @@ void loop()
    Serial.print("    BTN2=");
    Serial.print(rawBtn2);
    Serial.print("    BTN3=");
-    Serial.println(rawBtn3);
+    Serial.print(rawBtn3);
+
+    Serial.println("");
+
+    Serial.print("Value from pin: ");
+    Serial.println(rawBat);
+    Serial.print("Average value from pin: ");
+    Serial.println(BL.pinRead());
+    Serial.print("Volts: ");
+    Serial.println(BL.getBatteryVolts());
+    Serial.print("Charge level: ");
+    Serial.println(BL.getBatteryChargeLevel());
+    Serial.println("");
    lastLogMs = now;
  }
  delay(50);