add sleep and wdt examples

Author: PRosenb

Diff for: SampleProjects/DoSomething/examples/AvrSleepInterrupt/.arduino-ci.yaml

@@ -0,0 +1,11 @@
+compile:
+  libraries: ~
+  platforms:
+    - uno
+    - leonardo
+
+unittest:
+  libraries: ~
+  platforms:
+    - uno
+    - leonardo

Diff for: SampleProjects/DoSomething/examples/AvrSleepInterrupt/AvrSleepInterrupt.ino

@@ -0,0 +1,27 @@
+#include <avr/sleep.h>
+
+#define BUTTON_INT_PIN 2
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println("start");
+  delay(200);
+  pinMode(BUTTON_INT_PIN, INPUT_PULLUP);
+  attachInterrupt(digitalPinToInterrupt(BUTTON_INT_PIN), isrButtonTrigger, FALLING);
+}
+
+void loop() {
+  // sleep unti an interrupt occurs
+  sleep_enable(); // enables the sleep bit, a safety pin
+  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
+  sleep_cpu(); // here the device is actually put to sleep
+  sleep_disable(); // disables the sleep bit, a safety pin
+
+  Serial.println("interrupt");
+  delay(200);
+}
+
+void isrButtonTrigger() {
+  // nothing to do, wakes up the CPU
+}
+

Diff for: SampleProjects/DoSomething/examples/AvrWdtReset/.arduino-ci.yaml

@@ -0,0 +1,11 @@
+compile:
+  libraries: ~
+  platforms:
+    - uno
+    - leonardo
+
+unittest:
+  libraries: ~
+  platforms:
+    - uno
+    - leonardo

Diff for: SampleProjects/DoSomething/examples/AvrWdtReset/AvrWdtReset.ino

@@ -0,0 +1,29 @@
+#include <avr/wdt.h>
+
+void setup() {
+  pinMode(LED_BUILTIN, OUTPUT);
+  digitalWrite(LED_BUILTIN, LOW);
+
+  wdt_enable(WDTO_4S);
+  // First timeout executes interrupt, second does reset.
+  // So first LED 4s off
+  // then LED 4s on
+  // then reset CPU and start again
+  WDTCSR |= (1 << WDIE);
+}
+
+void loop() {
+  // the program is alive...for now.
+  wdt_reset();
+
+  while (1)
+    ; // do nothing. the program will lockup here.
+
+  // Can not get here
+}
+
+ISR (WDT_vect) {
+  // WDIE & WDIF is cleared in hardware upon entering this ISR
+  digitalWrite(LED_BUILTIN, HIGH);
+}
+