[RN8209] Add task WDT (#1657)

Add WDT and reduce update as we now have a change based pub mechanism
Base the change detection on current rather than power and simplify it
Round the result to 2 digits after comma
Add docs

main/ZsensorRN8209.ino

@@ -26,6 +26,8 @@
 */
 #ifdef ZsensorRN8209
 
+#  include <esp_task_wdt.h>
+
 #  include "ArduinoJson.h"
 #  include "driver/uart.h"
 #  include "rn8209_flash.h"
@@ -37,7 +39,10 @@ float voltage = 0;
 float current = 0;
 float power = 0;
 
+TaskHandle_t rn8209TaskHandle = nullptr;
+
 unsigned long PublishingTimerRN8209 = 0;
+StaticJsonDocument<JSON_MSG_BUFFER> doc;
 
 void rn8209_loop(void* mode) {
   while (1) {
@@ -46,46 +51,51 @@ void rn8209_loop(void* mode) {
     uint8_t ret = rn8209c_read_emu_status();
     uint8_t retc = 1;
     uint8_t retp = 1;
-    static float previousPower = 0;
+    static float previousCurrent = 0;
     if (ret) {
       uint32_t temp_current = 0;
-      uint32_t temp_power = 0;
       retc = rn8209c_read_current(phase_A, &temp_current);
-      retp = rn8209c_read_power(phase_A, &temp_power);
       if (ret == 1) {
         current = temp_current;
-        power = temp_power;
       } else {
         current = (int32_t)temp_current * (-1);
-        power = (int32_t)temp_power * (-1);
       }
       if (retc == 0) {
         current = current / 10000.0;
         overLimitCurrent(current);
       }
     }
-    StaticJsonDocument<128> doc;
-    JsonObject data = doc.to<JsonObject>();
-    if (retc == 0) {
-      data["current"] = current;
-    }
-    if (retv == 0) {
-      voltage = (float)temp_voltage / 1000.0;
-      data["volt"] = voltage;
-    }
-    if (retp == 0) {
-      power = power / 10000.0;
-      data["power"] = power;
-    }
     unsigned long now = millis();
     if ((now > (PublishingTimerRN8209 + TimeBetweenPublishingRN8209) ||
          !PublishingTimerRN8209 ||
-         (abs(power - previousPower) > previousPower * PreviousPowerThreshold) && abs(power - previousPower) > MinPowerThreshold) &&
+         (abs(current - previousCurrent) > MinCurrentThreshold)) &&
         !ProcessLock) {
+      JsonObject data = doc.to<JsonObject>();
+      if (retc == 0) {
+        data["current"] = round2(current);
+      }
+      uint32_t temp_power = 0;
+      retp = rn8209c_read_power(phase_A, &temp_power);
+      if (retv == 0) {
+        voltage = (float)temp_voltage / 1000.0;
+        data["volt"] = round2(voltage);
+      }
+      if (ret == 1) {
+        power = temp_power;
+      } else {
+        power = (int32_t)temp_power * (-1);
+      }
+      if (retp == 0) {
+        power = power / 10000.0;
+        data["power"] = round2(power);
+      }
       PublishingTimerRN8209 = now;
-      previousPower = power;
-      if (data) pub(subjectRN8209toMQTT, data);
+      previousCurrent = current;
+      if (data) {
+        pub(subjectRN8209toMQTT, data);
+      }
     }
+    esp_task_wdt_reset();
     delay(TimeBetweenReadingRN8209);
   }
 }
@@ -97,7 +107,9 @@ void setupRN8209() {
   cal.EC = RN8209_EC;
   set_user_param(cal);
   init_8209c_interface();
-  xTaskCreate(rn8209_loop, "rn8209_loop", RN8209_TASK_STACK_SIZE, NULL, 10, NULL);
+  esp_task_wdt_init(TimeOutWDTRN8209, true);
+  xTaskCreate(rn8209_loop, "rn8209_loop", 5000, NULL, 10, &rn8209TaskHandle);
+  esp_task_wdt_add(rn8209TaskHandle);
   Log.trace(F("ZsensorRN8209 setup done " CR));
 }
 

main/config_RN8209.h

@@ -46,13 +46,14 @@ extern void RN8209toMQTT();
 #ifndef TimeBetweenReadingRN8209
 #  define TimeBetweenReadingRN8209 500 // time between 2 RN8209 readings in ms
 #endif
+
+#ifndef TimeOutWDTRN8209
+#  define TimeOutWDTRN8209 60 // time out if RN8209 task is stuck in seconds (should be more than TimeBetweenReadingRN8209/1000), the WDT will reset the ESP
+#endif
 #ifndef TimeBetweenPublishingRN8209
-#  define TimeBetweenPublishingRN8209 10000 // time between 2 RN8209 publishing in ms
+#  define TimeBetweenPublishingRN8209 60000 // time between 2 RN8209 publishing in ms
 #endif
-#ifndef PreviousPowerThreshold
-#  define PreviousPowerThreshold 0.1 // (percentage) threshold of the previous power that will trigger the publishing of the power value
-#endif
-#ifndef MinPowerThreshold
-#  define MinPowerThreshold 1 // (watt) Minimum power threshold that will trigger the publishing of the power value combined with PreviousPowerThreshold
+#ifndef MinCurrentThreshold
+#  define MinCurrentThreshold 0.1 // (A) Minimum current change that will trigger the publishing of the RN8209 measurements
 #endif
 #endif

main/main.ino

@@ -338,6 +338,14 @@ long value_from_hex_data(const char* service_data, int offset, int data_length,
   return value;
 }
 
+/*
+ rounds a number to 2 decimal places
+ example: round(3.14159) -> 3.14
+*/
+double round2(double value) {
+  return (int)(value * 100 + 0.5) / 100.0;
+}
+
 /*
 From an hexa char array ("A220EE...") to a byte array (half the size)
  */