add Low-Power demo

libraries/esp8266/examples/LowPowerDemo/LowPowerDemo.ino

@@ -39,11 +39,11 @@
 #define DEBUG_PRINT(x)
 #endif
 
-#define WAKE_UP_PIN D3  // GPIO0, can also force a serial flash upload with RESET
+#define WAKE_UP_PIN 0  // D3/GPIO0, can also force a serial flash upload with RESET
 
 // un-comment one of the two lines below for your LED connection
-#define LED D1  // external LED for modules with built-in LEDs so it doesn't add to the current
-//#define LED D4  // GPIO2 LED for ESP-01,07 modules; D4 is LED_BUILTIN on most other modules
+#define LED 5  // D1/GPIO5 external LED for modules with built-in LEDs so it doesn't add to the current
+//#define LED 2  // D4/GPIO2 LED for ESP-01,07 modules; D4 is LED_BUILTIN on most other modules
 
 ADC_MODE(ADC_VCC);  // allows us to monitor the internal VCC level; it varies with WiFi load
 // don't connect anything to the analog input pin(s)!
@@ -69,7 +69,7 @@ struct {
   byte data[4];  // the last byte stores the reset count
 } rtcData;
 
-byte resetLoop = 0;  // keeps track of the number of Deep Sleep tests / resets
+byte resetCount = 0;  // keeps track of the number of Deep Sleep tests / resets
 String resetCause = "";
 
 const unsigned int blinkDelay = 100; // fast blink rate for the LED when waiting for the user
@@ -91,23 +91,23 @@ void setup() {
   Serial.println(resetCause);
   if (resetCause == "External System") {
     Serial.println(F("I'm awake and starting the low power tests"));
-    resetLoop = 5;
+    resetCount = 5;
     updateRTC();  // if external reset, wipe the RTC memory and start all over
   }
 
   // Read struct from RTC memory
   if (ESP.rtcUserMemoryRead(64, (uint32_t*) &rtcData, sizeof(rtcData))) {
     uint32_t crcOfData = calculateCRC32((uint8_t*) &rtcData.data[0], sizeof(rtcData.data));
     if (crcOfData != rtcData.crc32) {  // if the CRC is invalid
-      resetLoop = 0;  // set first test loop since power on or external reset
+      resetCount = 0;  // set first test loop since power on or external reset
     } else {
-      resetLoop = rtcData.data[3];  // read the previous reset count
+      resetCount = rtcData.data[3];  // read the previous reset count
     }
   }
 }  // end of Setup()
 
 void loop() {
-  if (resetLoop == 0) {
+  if (resetCount == 0) {
     // 1st test - running with WiFi unconfigured, reads ~67 mA minimum
     Serial.println(F("\n1st test - running with WiFi unconfigured"));
     float volts = ESP.getVcc();
@@ -171,7 +171,7 @@ void loop() {
     Serial.println(F("\n6th test - Deep Sleep for 10 seconds, wake with RF_DEFAULT"));
     init_WiFi();  // initialize WiFi since we turned it off in the last test
     init_OTA();
-    resetLoop = 1;  // advance to the next Deep Sleep test after the reset
+    resetCount = 1;  // advance to the next Deep Sleep test after the reset
     updateRTC();  // save the current test state in RTC memory
     volts = ESP.getVcc();
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000 );
@@ -192,12 +192,12 @@ void loop() {
   }
 
   // 7th test - Deep Sleep for 10 seconds, wake with RFCAL
-  if (resetLoop < 4) {
+  if (resetCount < 4) {
     init_WiFi();  // need to reinitialize WiFi & OTA due to Deep Sleep resets
     init_OTA();   // since we didn't do it in setup() because of the first test
   }
-  if (resetLoop == 1) {  // second reset loop since power on
-    resetLoop = 2;  // advance to the next Deep Sleep test after the reset
+  if (resetCount == 1) {  // second reset loop since power on
+    resetCount = 2;  // advance to the next Deep Sleep test after the reset
     updateRTC();  // save the current test state in RTC memory
     Serial.println(F("\n7th test - in RF_DEFAULT, Deep Sleep for 10 seconds, wake with RFCAL"));
     float volts = ESP.getVcc();
@@ -212,8 +212,8 @@ void loop() {
   }
 
   // 8th test - Deep Sleep Instant for 10 seconds, wake with NO_RFCAL
-  if (resetLoop == 2) {  // third reset loop since power on
-    resetLoop = 3;  // advance to the next Deep Sleep test after the reset
+  if (resetCount == 2) {  // third reset loop since power on
+    resetCount = 3;  // advance to the next Deep Sleep test after the reset
     updateRTC();  // save the current test state in RTC memory
     Serial.println(F("\n8th test - in RFCAL, Deep Sleep Instant for 10 seconds, wake with NO_RFCAL"));
     float volts = ESP.getVcc();
@@ -228,8 +228,8 @@ void loop() {
   }
 
   // 9th test - Deep Sleep Instant for 10 seconds, wake with RF_DISABLED
-  if (resetLoop == 3) {  // fourth reset loop since power on
-    resetLoop = 4;  // advance to the next Deep Sleep test after the reset
+  if (resetCount == 3) {  // fourth reset loop since power on
+    resetCount = 4;  // advance to the next Deep Sleep test after the reset
     updateRTC();  // save the current test state in RTC memory
     Serial.println(F("\n9th test - in NO_RFCAL, Deep Sleep Instant for 10 seconds, wake with RF_DISABLED"));
     float volts = ESP.getVcc();
@@ -243,8 +243,8 @@ void loop() {
     Serial.println(F("What... I'm not asleep?!?"));  // it will never get here
   }
 
-  if (resetLoop == 4) {
-    resetLoop = 5;  // start all over
+  if (resetCount == 4) {
+    resetCount = 5;  // start all over
     updateRTC();  // save the current test state in RTC memory
     float volts = ESP.getVcc();
     Serial.printf("The internal VCC reads %1.3f volts\n", volts / 1000 );
@@ -299,10 +299,10 @@ uint32_t calculateCRC32(const uint8_t *data, size_t length) {
 }
 
 void updateRTC() {
-  rtcData.data[3] = resetLoop;  // save the loop count for the next reset
+  rtcData.data[3] = resetCount;  // save the loop count for the next reset
   // Update CRC32 of data
   rtcData.crc32 = calculateCRC32((uint8_t*) &rtcData.data[0], sizeof(rtcData.data));
-  if (resetLoop == 5)  // wipe the CRC in RTC memory when we're done with all tests
+  if (resetCount == 5)  // wipe the CRC in RTC memory when we're done with all tests
     rtcData.crc32 = 0;
   // Write struct to RTC memory
   ESP.rtcUserMemoryWrite(64, (uint32_t*) &rtcData, sizeof(rtcData));

libraries/esp8266/examples/LowPowerDemo/README.md

@@ -48,11 +48,11 @@ This is typical for programs that don't use WiFi, and is a high current drain of
 
 ### Test 2 - Automatic Modem Sleep
 
-This is the default power saving mode when you have an active WiFi connection.  You don't need to add anything to your code to get it.  However, it's not as wonderful as it may seem, as the only time the modem sleeps is when you spend a long time in delay(), with delay times over 50mS.  The LED blinks more slowly during this test as I'm doing delay(350) to get the modem to sleep.  While in delay() your sketch isn't doing anything interesting.  Average current during long delay()s is 15 mA minimum.  Without the delay() the average current is 67 mA with short spikes above 250 mA as transmissions occur.  When the WiFi has traffic (even couple of pings), the modem can turn on for over 2 seconds continuous at 67 mA, and it may stay on for a second after the traffic.  In a high traffic environment you won't get any power savings with either of the 2 Automatic modes.  Automatic Modem Sleep turns on 7-8 seconds after an active connection is established.
+This is the default power saving mode when you have an active WiFi connection.  You don't need to add anything to your code to get it.  However, it's not as wonderful as it may seem, as the only time the modem sleeps is when you spend a long time in delay(), with delay times over 50mS.  The LED blinks more slowly during this test as I'm doing delay(350) to get the modem to sleep.  While in delay() your sketch isn't doing anything interesting.  Average current during long delay()s is 15 mA minimum.  Without the delay() the average current is 67 mA with short spikes above 250 mA as transmissions occur.  When the WiFi has traffic (even a couple of pings), the modem can turn on for over 2 seconds continuous at 67 mA, and it may stay on for a second after the traffic.  In a high traffic environment you won't get any power savings with either of the 2 Automatic modes.  Automatic Modem Sleep turns on 7-8 seconds after an active connection is established.
 
 ### Test 3 - Forced Modem Sleep
 
-Turns off the modem (losing the connection), and dropping the current by 50 mA.  This uses the WiFi library function.  It's good if there is a long interval with no expected traffic, as you can do other things while only drawing 15 mA.
+Turns off the modem (losing the connection), and dropping the current by 50 mA.  This uses the WiFi library function.  It's good if there is a long interval with no expected WiFi traffic, as you can do other things while only drawing 15 mA.
 
 ### Test 4 - Automatic Light Sleep
 
@@ -68,7 +68,7 @@ In Deep Sleep almost everything is turned off, and the chip draws ~20 uA.  If yo
 
 ### Test 7 - Deep Sleep, wake with RFCAL
 
-Identical to the test above, but the modem does a power calibration when booting.  In normal use, I'd likely do WAKE_RF_DEFAULT instead to save the extra RFCAL power burst if it's not needed.
+Identical to the test above, but the modem does a power calibration when booting.  In normal use, I'd likely do WAKE_RF_DEFAULT instead to minimize the extra RFCAL power burst if it's not needed.
 
 ### Test 8 - Deep Sleep Instant, wake with NO_RFCAL