Merge pull request #33 from brentru/add-esp32-support

Add support for ESP32

Adafruit_SleepyDog.h

@@ -28,6 +28,9 @@ typedef WatchdogKinetisLseries WatchdogType;
 #elif defined(NRF52_SERIES)
 #include "utility/WatchdogNRF.h"
 typedef WatchdogNRF WatchdogType;
+#elif defined(ARDUINO_ARCH_ESP32)
+#include "utility/WatchdogESP32.h"
+typedef WatchdogESP32 WatchdogType;
 #else
 #error Unsupported platform for the Adafruit Watchdog library!
 #endif

README.md

@@ -11,3 +11,4 @@ Currently supports the following hardware:
 *  Arduino Leonardo or other 32u4-based boards (e.g. Adafruit Feather) WITH CAVEAT: USB Serial connection is clobbered on sleep; if sketch does not require Serial comms, this is not a concern. The example sketches all print to Serial and appear frozen, but the logic does otherwise continue to run. You can restore the USB serial connection after waking up using `USBDevice.attach();` and then reconnect to USB serial from the host machine.
 *  Partial support for Teensy 3.X and LC (watchdog, no sleep).
 *  ATtiny 24/44/84 and 25/45/85
+*  ESP32, ESP32-S2

library.properties

@@ -1,9 +1,9 @@
 name=Adafruit SleepyDog Library
-version=1.4.0
+version=1.5.0
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=Arduino library to use the watchdog timer for system reset and low power sleep.
 paragraph=Arduino library to use the watchdog timer for system reset and low power sleep.
 category=Other
 url=https://github.com/adafruit/Adafruit_SleepyDog
-architectures=avr,samd,nrf52,teensy
+architectures=avr,samd,nrf52,teensy, esp32

utility/WatchdogESP32.cpp

@@ -0,0 +1,83 @@
+#if defined(ARDUINO_ARCH_ESP32)
+
+#include "WatchdogESP32.h"
+
+/**************************************************************************/
+/*!
+    @brief  Initializes the ESP32's Task Watchdog Timer (TWDT) and
+            subscribes to the current running task.
+    @param    maxPeriodMS
+              Timeout period of TWDT in seconds
+    @return The actual period (in milliseconds) before a watchdog timer
+            reset is returned. 0 otherwise.
+*/
+/**************************************************************************/
+int WatchdogESP32::enable(int maxPeriodMS) {
+  if (maxPeriodMS < 0)
+    return 0;
+
+  // ESP32 expects TWDT in seconds
+  uint32_t maxPeriod = maxPeriodMS / 1000;
+  // Enable the TWDT and execute the esp32 panic handler when TWDT times out
+  esp_err_t err = esp_task_wdt_init(maxPeriod, true);
+  if (err != ESP_OK)
+    return 0; // Initialization failed due to lack of memory
+
+  // NULL to subscribe the current running task to the TWDT
+  err = esp_task_wdt_add(NULL);
+  if (err != ESP_OK)
+    return 0;
+
+  _wdto = maxPeriodMS;
+  return maxPeriodMS;
+}
+
+/**************************************************************************/
+/*!
+    @brief  Resets the Task Watchdog Timer (TWDT) on behalf
+            of the currently running task.
+*/
+/**************************************************************************/
+void WatchdogESP32::reset() {
+  // NOTE: This blindly resets the TWDT and does not return the esp_err.
+  esp_task_wdt_reset();
+}
+
+/**************************************************************************/
+/*!
+    @brief  Disables the TWDT by unsubscribing the currently running task
+            from the TWDT.
+*/
+/**************************************************************************/
+void WatchdogESP32::disable() { esp_task_wdt_delete(NULL); }
+
+/**************************************************************************/
+/*!
+    @brief  Configures the ESP32 to enter a low-power sleep mode for a
+            desired amount of time.
+    @param    maxPeriodMS
+              Time to sleep the ESP32, in millis.
+    @return The actual period (in milliseconds) that the hardware was
+            asleep will be returned. Otherwise, 0 will be returned if the
+            hardware could not enter the low-power mode.
+*/
+/**************************************************************************/
+int WatchdogESP32::sleep(int maxPeriodMS) {
+  if (maxPeriodMS < 0)
+    return 0;
+  // Convert from MS to microseconds
+  uint64_t sleepTime = maxPeriodMS * 1000;
+  // Enable wakeup by timer
+  esp_err_t err = esp_sleep_enable_timer_wakeup(sleepTime);
+  if (err != ESP_OK) {
+    return 0; // sleepTime is out of range
+  }
+  // Enter light sleep with the timer wakeup option configured
+  err = esp_light_sleep_start();
+  if (err != ESP_OK) {
+    return 0; // ESP_ERR_INVALID_STATE if WiFi or BT is not stopped
+  }
+  return maxPeriodMS;
+}
+
+#endif // ARDUINO_ARCH_ESP32

utility/WatchdogESP32.h

@@ -0,0 +1,38 @@
+/*!
+ * @file WatchdogESP32.h
+ *
+ * Support for ESP32 TWDT and low-power sleep modes.
+ *
+ * Adafruit invests time and resources providing this open source code,
+ * please support Adafruit and open-source hardware by purchasing
+ * products from Adafruit!
+ *
+ * Written by Brent Rubell for Adafruit Industries.
+ *
+ * MIT License, all text here must be included in any redistribution.
+ *
+ */
+#ifndef WATCHDOGESP32_H_
+#define WATCHDOGESP32_H_
+#include "esp_sleep.h"
+#include "esp_task_wdt.h"
+
+/**************************************************************************/
+/*!
+    @brief  Class that contains functions for interacting with the ESP32's
+            WDT and low-power sleep functions.
+*/
+/**************************************************************************/
+class WatchdogESP32 {
+public:
+  WatchdogESP32() : _wdto(-1){};
+  int enable(int maxPeriodMS = 0);
+  void reset();
+  void disable();
+  int sleep(int maxPeriodMS = 0);
+
+private:
+  int _wdto;
+};
+
+#endif // WATCHDOGESP32_H