Adding watchdog for SAMD architecture

.github/workflows/compile-examples.yml

@@ -63,6 +63,7 @@ jobs:
               - name: ArduinoECCX08
               - name: RTCZero
               - name: WiFi101
+              - source-url: https://github.com/adafruit/Adafruit_SleepyDog.git
             sketch-paths: |
               - examples/utility/Provisioning
           # MKR WiFi 1010, Nano 33 IoT
@@ -77,6 +78,7 @@ jobs:
               - name: WiFiNINA
               - name: Arduino_JSON
               - name: ArduinoBearSSL
+              - source-url: https://github.com/adafruit/Adafruit_SleepyDog.git
             sketch-paths: |
               - examples/utility/Provisioning
               - examples/utility/SelfProvisioning
@@ -113,6 +115,7 @@ jobs:
               - name: ArduinoECCX08
               - name: RTCZero
               - name: MKRGSM
+              - source-url: https://github.com/adafruit/Adafruit_SleepyDog.git
             sketch-paths: |
               - examples/utility/Provisioning
           # NB boards
@@ -124,6 +127,7 @@ jobs:
               - name: ArduinoECCX08
               - name: RTCZero
               - name: MKRNB
+              - source-url: https://github.com/adafruit/Adafruit_SleepyDog.git
             sketch-paths: |
               - examples/utility/Provisioning
           # Portenta

src/ArduinoIoTCloudTCP.cpp

@@ -43,6 +43,8 @@
 
 #include "cbor/CBOREncoder.h"
 
+#include "utility/watchdog/Watchdog.h"
+
 /******************************************************************************
  * EXTERN
  ******************************************************************************/
@@ -262,11 +264,27 @@ int ArduinoIoTCloudTCP::begin(String brokerAddress, uint16_t brokerPort)
   }
 #endif /* OTA_STORAGE_SNU */
 
+#ifdef ARDUINO_ARCH_SAMD
+  /* Since we do not control what code the user inserts
+   * between ArduinoIoTCloudTCP::begin() and the first
+   * call to ArduinoIoTCloudTCP::update() it is wise to
+   * set a rather large timeout at first.
+   */
+  Watchdog.enable(SAMD_WATCHDOG_MAX_TIME_ms);
+#endif /* ARDUINO_ARCH_SAMD */
+
   return 1;
 }
 
 void ArduinoIoTCloudTCP::update()
 {
+#ifdef ARDUINO_ARCH_SAMD
+  /* Feed the watchdog. If any of the functions called below
+   * get stuck than we can at least reset and recover.
+   */
+  Watchdog.reset();
+#endif /* ARDUINO_ARCH_SAMD */
+
   /* Run through the state machine. */
   State next_state = _state;
   switch (_state)
@@ -522,13 +540,21 @@ int ArduinoIoTCloudTCP::write(String const topic, byte const data[], int const l
 #if OTA_ENABLED
 void ArduinoIoTCloudTCP::onOTARequest()
 {
+#ifdef ARDUINO_ARCH_SAMD
+  Watchdog.reset();
+#endif /* ARDUINO_ARCH_SAMD */
+
   DEBUG_VERBOSE("ArduinoIoTCloudTCP::%s _ota_url = %s", __FUNCTION__, _ota_url.c_str());
 
 #if OTA_STORAGE_SNU
   /* Just to be safe delete any remains from previous updates. */
   WiFiStorage.remove("/fs/UPDATE.BIN.LZSS");
   WiFiStorage.remove("/fs/UPDATE.BIN.LZSS.TMP");
 
+#ifdef ARDUINO_ARCH_SAMD
+  Watchdog.reset();
+#endif /* ARDUINO_ARCH_SAMD */
+
   /* Trigger direct download to nina module. */
   uint8_t nina_ota_err_code = 0;
   if (!WiFiStorage.downloadOTA(_ota_url.c_str(), &nina_ota_err_code))

src/utility/watchdog/Watchdog.h

@@ -0,0 +1,30 @@
+/*
+   This file is part of ArduinoIoTCloud.
+
+   Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+
+   This software is released under the GNU General Public License version 3,
+   which covers the main part of arduino-cli.
+   The terms of this license can be found at:
+   https://www.gnu.org/licenses/gpl-3.0.en.html
+
+   You can be released from the requirements of the above licenses by purchasing
+   a commercial license. Buying such a license is mandatory if you want to modify or
+   otherwise use the software for commercial activities involving the Arduino
+   software without disclosing the source code of your own applications. To purchase
+   a commercial license, send an email to [email protected].
+*/
+
+#ifndef ARDUINO_AIOTC_UTILITY_WATCHDOG_H_
+#define ARDUINO_AIOTC_UTILITY_WATCHDOG_H_
+
+/******************************************************************************
+ * INCLUDE
+ ******************************************************************************/
+
+#ifdef ARDUINO_ARCH_SAMD
+#  include <Adafruit_SleepyDog.h>
+#  define SAMD_WATCHDOG_MAX_TIME_ms (16 * 1000)
+#endif /* ARDUINO_ARCH_SAMD */
+
+#endif /* ARDUINO_AIOTC_UTILITY_WATCHDOG_H_ */