add Low-Power demo

esp8266 · devyte · Feb 2, 2020 · Jan 6, 2020 · Jan 6, 2020 · Jan 9, 2020
commit 56956263f409faa7afbda753911fe72305cbbd21
diff --git a/libraries/esp8266/examples/LowPowerDemo/LowPowerDemo.ino b/libraries/esp8266/examples/LowPowerDemo/LowPowerDemo.ino
@@ -68,6 +68,8 @@ IPAddress dns1(0, 0, 0, 0);
 IPAddress dns2(0, 0, 0, 0);
 uint32_t wifiTimeout = 25E3;  // 25 second timeout on the WiFi connection
 
+//#define testPoint 4  // D2/GPIO4 used to track the timing of several test cycles, entirely optional
+
 // This structure will be stored in RTC memory to remember the reset count (number of Deep Sleeps).
 // First field is CRC32, which is calculated based on the rest of the structure contents.
 // Any fields can go after the CRC32.  The structure must be 4-byte aligned.
@@ -77,18 +79,25 @@ struct {
 } rtcData;
 
 byte resetCount = 0;  // keeps track of the number of Deep Sleep tests / resets
-String resetCause = "";
 
 const uint32_t blinkDelay = 100; // fast blink rate for the LED when waiting for the user
 const uint32_t longDelay = 350;  // longer delay() for the two AUTOMATIC modes
-esp8266::polledTimeout::periodicFastMs blinkLED(blinkDelay);
+esp8266::polledTimeout::periodicMs blinkLED(blinkDelay);
+esp8266::polledTimeout::oneShotFastMs altDelay(blinkDelay);
 // use fully qualified type and avoid importing all ::esp8266 namespace to the global namespace
 
 void wakeupCallback() {  // unlike ISRs, you can do a print() from a callback function
+#ifdef testPoint
+  digitalWrite(testPoint, LOW);  // testPoint tracks latency from WAKE_UP_PIN LOW to testPoint LOW
+#endif
   Serial.println(F("Woke from Forced Light Sleep - this is the callback"));
 }
 
 void setup() {
+#ifdef testPoint
+  pinMode(testPoint, OUTPUT);  // test point for Forced Light Sleep and Deep Sleep tests
+  digitalWrite(testPoint, LOW);  // Deep Sleep reset doesn't clear GPIOs, testPoint falling shows boot time
+#endif
   pinMode(LED, OUTPUT);  // activity and status indicator
   digitalWrite(LED, LOW);  // turn on the LED
   pinMode(WAKE_UP_PIN, INPUT_PULLUP);  // polled to advance tests, interrupt for Forced Light Sleep
@@ -131,7 +140,13 @@ void loop() {
       volts = ESP.getVcc();
       Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
       Serial.println(F("press the button to continue"));
-      waitPushbutton(true, longDelay);
+      waitPushbutton(true, 90);  /* This is using a special feature: below 100 mS blink delay,
+         the LED blink delay is padding the time with 'program cycles' to fill the 100 mS. At 90 mS
+         delay, 90% of the blink time is delay(), and 10% is 'your program running'. Below 90% you
+         will see a difference in the average amperage, less delay() = more amperage.  At 100 mS
+         and above it's essentially all delay() time.  On an oscilloscope you'll see the time
+         between beacons at > 67 mA more often with less delay() percentage. You can change the
+         '90' mS to other values to see the effect it has on Automatic Modem Sleep. */
     } else {
       Serial.println(F("no WiFi connection, test skipped"));
     }
@@ -144,7 +159,10 @@ void loop() {
     volts = ESP.getVcc();
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
     Serial.println(F("press the button to continue"));
-    waitPushbutton(true, longDelay);
+    waitPushbutton(true, 99);  /* Using the same < 100 mS feature. If you drop the delay below 100, you
+      will see the effect of program time vs. delay() time on minimum amperage.  Above ~ 97 (97% of the
+      time in delay) there is little change in amperage, so you need to spend maximum time in delay()
+      to get minimum amperage. At a high percentage of delay() you will see minimum amperage. */
 
     // 4th test - Automatic Light Sleep
     Serial.println(F("\n4th test - Automatic Light Sleep"));
@@ -161,7 +179,9 @@ void loop() {
       volts = ESP.getVcc();
       Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
       Serial.println(F("press the button to continue"));
-      waitPushbutton(true, longDelay);
+      waitPushbutton(true, 350);  /* Below 100 mS delay it only goes into 'Automatic Modem Sleep',
+        and below ~ 350 mS delay() the 'Automatic Light Sleep' is less frequent.  Above 350 mS
+        delay() doesn't make much improvement in power savings. */
     } else {
       Serial.println(F("no WiFi connection, test skipped"));
     }
@@ -171,6 +191,9 @@ void loop() {
     WiFi.mode(WIFI_OFF);  // you must turn the modem off; using disconnect won't work
     yield();
     digitalWrite(LED, HIGH);  // turn the LED off so they know the CPU isn't running
+#ifdef testPoint
+    digitalWrite(testPoint, HIGH);  // testPoint LOW in callback tracks latency from WAKE_UP_PIN LOW to testPoint LOW
+#endif
     volts = ESP.getVcc();
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
     Serial.println(F("CPU going to sleep, pull WAKE_UP_PIN low to wake it (press the button)"));
@@ -198,8 +221,13 @@ void loop() {
     delay(50);  // debounce time for the switch, button released
     waitPushbutton(false, blinkDelay);  // set true if you want to see Automatic Modem Sleep
     digitalWrite(LED, LOW);  // turn the LED on, at least briefly
+    //WiFi.mode(WIFI_SHUTDOWN);  // Forced Modem Sleep for a more Instant Deep Sleep, and no long
+    // RFCAL as it goes into Deep Sleep
     Serial.println(F("going into Deep Sleep now..."));
     Serial.flush();  // needs a delay(10) or Serial.flush() else it doesn't print the whole message
+#ifdef testPoint
+    digitalWrite(testPoint, HIGH);  // testPoint set HIGH to track Deep Sleep period, cleared at startup()
+#endif
     ESP.deepSleep(10E6, WAKE_RF_DEFAULT); // good night!  D0 fires a reset in 10 seconds...
     delay(10);
     // if you do ESP.deepSleep(0, mode); it needs a RESET to come out of sleep (RTC is off)
@@ -221,8 +249,13 @@ void loop() {
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
     Serial.println(F("press the button to continue"));
     waitPushbutton(false, blinkDelay);  // set true if you want to see Automatic Modem Sleep
+    //WiFi.mode(WIFI_SHUTDOWN);  // Forced Modem Sleep for a more Instant Deep Sleep, and no RFCAL
+    // as it goes into Deep Sleep
     Serial.println(F("going into Deep Sleep now..."));
     Serial.flush();  // needs a delay(10) or Serial.flush() else it doesn't print the whole message
+#ifdef testPoint
+    digitalWrite(testPoint, HIGH);  // testPoint set HIGH to track Deep Sleep period, cleared at startup()
+#endif
     ESP.deepSleep(10E6, WAKE_RFCAL); // good night!  D0 fires a reset in 10 seconds...
     delay(10);
     Serial.println(F("What... I'm not asleep?!?"));  // it will never get here
@@ -237,8 +270,13 @@ void loop() {
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
     Serial.println(F("press the button to continue"));
     waitPushbutton(false, blinkDelay);  // set true if you want to see Automatic Modem Sleep
+    //WiFi.mode(WIFI_SHUTDOWN);  // Forced Modem Sleep for a more Instant Deep Sleep, and no RFCAL
+    // as it goes into Deep Sleep
     Serial.println(F("going into Deep Sleep now..."));
     Serial.flush();  // needs a delay(10) or Serial.flush() else it doesn't print the whole message
+#ifdef testPoint
+    digitalWrite(testPoint, HIGH);  // testPoint set HIGH to track Deep Sleep period, cleared at startup()
+#endif
     ESP.deepSleepInstant(10E6, WAKE_NO_RFCAL); // good night!  D0 fires a reset in 10 seconds...
     delay(10);
     Serial.println(F("What... I'm not asleep?!?"));  // it will never get here
@@ -253,8 +291,12 @@ void loop() {
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000);
     Serial.println(F("press the button to continue"));
     waitPushbutton(false, blinkDelay);  // set true if you want to see Automatic Modem Sleep
+    // WiFi.mode(WIFI_SHUTDOWN);  // Forced Modem Sleep for a more Instant Deep Sleep
     Serial.println(F("going into Deep Sleep now..."));
     Serial.flush();  // needs a delay(10) or Serial.flush() else it doesn't print the whole message
+#ifdef testPoint
+    digitalWrite(testPoint, HIGH);  // testPoint set HIGH to track Deep Sleep period, cleared at startup()
+#endif
     ESP.deepSleepInstant(10E6, WAKE_RF_DISABLED); // good night!  D0 fires a reset in 10 seconds...
     delay(10);
     Serial.println(F("What... I'm not asleep?!?"));  // it will never get here
@@ -272,7 +314,7 @@ void loop() {
 }
 
 void waitPushbutton(bool usesDelay, unsigned int delayTime) {  // loop until they press the button
-  // note: 2 different modes, as both of the AUTOMATIC power saving modes need a long delay()
+  // note: 2 different modes, as 3 of the power saving modes need a delay() to activate fully
   if (!usesDelay) {  // quick interception of button press, no delay() used
     blinkLED.reset(delayTime);
     while (digitalRead(WAKE_UP_PIN)) {  // wait for a button press
@@ -281,10 +323,15 @@ void waitPushbutton(bool usesDelay, unsigned int delayTime) {  // loop until the
       }
       yield();  // this would be a good place for ArduinoOTA.handle();
     }
-  } else {  // long delay() for the 2 AUTOMATIC modes, but it misses quick button presses
+  } else {  // long delay() for the 3 modes that need it, but it misses quick button presses
     while (digitalRead(WAKE_UP_PIN)) {  // wait for a button press
       digitalWrite(LED, !digitalRead(LED));  // toggle the activity LED
       delay(delayTime);  // another good place for ArduinoOTA.handle();
+      if (delayTime < 100) {
+        altDelay.reset(100 - delayTime);  // pad the time < 100 mS with some real CPU cycles
+        while (!altDelay) {  // this simulates 'your program running', not delay() time
+        }
+      }
     }
   }
   delay(50);  // debounce time for the switch, button pressed