Best practice task watchdog timer implementation: ESP32 & SIM800

[Markovicz]

Dear Esp32-fellows,

I'm using following SIM800 & ESP32 board from lilygo:
https://github.com/Xinyuan-LilyGO/LilyGo-T-Call-SIM800

More precisely the ip5306 version that has been discontinued.

My code performs following tasks: 1) connect to mqtt broker (Cayenne) that uses the tinygsm library to 2) establish network connection and then 3) perform some measurements and send the data.

My 'prototype' has been working for like a week already but occasionally it just freezes and seems to hang in the finding network stage, which is indicated by the slow blining of the module.

So I've tried implementing a task watchdog timer, according to a very simple example here:
https://iotassistant.io/esp32/enable-ha ... duino-ide/

It also works and fires however the board still freezes occasionally. Could this have something to do that i am initializing the wdt in setup() and then different functions are called that are eventually not subscribed to the wdt task?

Code: Select all

//*
bool connected_ = false;
#define ARRAY_SIZE 20
double distance_array_5[ARRAY_SIZE] = {0};
double distance_array_5_installation[ARRAY_SIZE] = {0};

// Your GPRS credentials (leave empty, if missing)
const char apn[] = "iot.1nce.net"; // Access point name. Leave empty if it is not needed.
const char gprsUser[] = ""; // GPRS User
const char gprsPass[] = ""; // GPRS Password
char simPIN[] = ""; // SIM pin number. Leave empty if it is not needed.

// ******Required for Wakeup***************
#include "driver/rtc_io.h"

// ******Required for Wakeup***************
#include <esp_task_wdt.h>
//3 seconds WDT
#define WDT_TIMEOUT 60


// *****Setting IP5306 (battery management IC) registers and address
#define IP5306_ADDR 0x75
#define IP5306_REG_SYS_CTL0 0x00
#define IP5306_REG_SYS_CTL1 0x01


// TTGO T-Call pin definitions
#define MODEM_RST            5
#define MODEM_PWKEY          4
#define MODEM_POWER_ON       23
#define MODEM_TX             27
#define MODEM_RX             26
#define I2C_SDA              21
#define I2C_SCL              22

// Set serial for debug console (to the Serial Monitor, default speed 115200)
#define SerialMon Serial
// Set serial for AT commands (to the module)
#define SerialAT  Serial1


// BME280 pins
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
Adafruit_BME280 bme; 
#define SEALEVELPRESSURE_HPA (1013.25)
//*************************************


// Pin assignment for analog sensors (Maxbotix US sensor)
const int ANALOG_PIN_0 = 35; // ADC1_0 GPIO36
const int enable_5 = 34;
int analog_value, distance_mm, distance_cm;
int distance;
//******************************************


// Configure TinyGSM library
#define TINY_GSM_MODEM_SIM800      // Modem is SIM800
#define TINY_GSM_RX_BUFFER   1024  // Set RX buffer to 1Kb
#include <CayenneMQTTGSM.h>
char username[] = "xx";
char password[] = "xx";
char clientID[] = "xx";

// Define the serial console for debug prints, if needed
//#define TINY_GSM_DEBUG SerialMon
//#define DUMP_AT_COMMANDS

#include <Wire.h>
#include <TinyGsmClient.h>
#include <Update.h>

#define SIM800L_IP5306_VERSION_20190610
#include "utilities.h"

TinyGsm modem(SerialAT);
#define uS_TO_S_FACTOR 1000000ULL  /* Conversion factor for micro seconds to seconds */
#define TIME_TO_SLEEP  250        /* Time ESP32 will go to sleep (in seconds) 250 corresponds pretty well to 5min */

// Server details
const char server[] = "vsh.pp.ua";
const char resource[] = "/TinyGSM/logo.txt";

const int  port = 80;

void setup() {
  // Set console baud rate
  SerialMon.begin(115200);
  delay(20);
  SerialMon.println("Configuring WDT...");
  esp_task_wdt_init(WDT_TIMEOUT, true); //enable panic so ESP32 restarts
  esp_task_wdt_add(NULL); //add current thread to WDT watch
  Wire.begin(I2C_SDA, I2C_SCL);
  pinMode(ANALOG_PIN_0, INPUT);
  pinMode(enable_5, OUTPUT);

    // Start power management
    if (setupPMU() == false) {
        Serial.println("Setting power error");
    }

  
  // Set-up modem reset, enable, power pins
  pinMode(MODEM_PWKEY, OUTPUT);
  pinMode(MODEM_RST, OUTPUT);
  pinMode(MODEM_POWER_ON, OUTPUT);
  digitalWrite(MODEM_PWKEY, LOW);
  digitalWrite(MODEM_RST, HIGH);
  digitalWrite(MODEM_POWER_ON, HIGH);

  // Set GSM module baud rate and UART pins
  SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
  delay(3000);

  esp_sleep_enable_ext0_wakeup(GPIO_NUM_27,0); //enable ext0 interrupt when going from high to low : https://lastminuteengineers.com/esp32-deep-sleep-wakeup-sources/
  rtc_gpio_pullup_en(GPIO_NUM_27); // pulling 27 normally high so when interrupting it can be pulled low
  
  // Restart takes quite some time
  // To skip it, call init() instead of restart()
  SerialMon.println("Initializing modem...");
  modem.restart();
  // Or, use modem.init() if you don't need the complete restart



// *************Not sure if this function is necessary but it sets the boost on mode of the IP5306 again
Wire.beginTransmission(IP5306_ADDR);
Wire.write(IP5306_REG_SYS_CTL0);
Wire.write(0b110111);
// 0x37 = 0b110111 TCALL example
/*
[1] Boost EN (default 1) [EXM note: if 0 ESP32 will not boot from battery]
[1] Charger EN (1) [EXM note: did not observe difference]
[1] Reserved (1) [EXM note: did not observe difference]
[1] Insert load auto power EN (1) [EXM note: did not observe difference]
[1] BOOST output normally open ( 1) [EXM note: if 0 will shutdown when
ESP32 sleeps after 32s]
[1] Key off EN: (0) [EXM note: could not detect difference]
*/
Wire.write(IP5306_REG_SYS_CTL1);
Wire.write(0x1D); // Set HEX:1D DEC:29 BIN:11101
/*
[1] Turn off boost control signal selection: short press twice
[1] Switch WLED flashlight control signal selection: short press twice
[1] Short press switch boost: disabled
[0] Whether to turn on Boost after VIN is pulled out: opened
[1] Batlow 3.0V Low Power Shutdown EN: enabled
*/
//***********************************************************************

  String modemInfo = modem.getModemInfo();
  SerialMon.print("Modem: ");
  SerialMon.println(modemInfo);

  // Unlock your SIM card with a PIN if needed
  if (strlen(simPIN) && modem.getSimStatus() != 3 ) {
    modem.simUnlock(simPIN);
  }
    SerialMon.println("Still in setup mode and calling Cayenne.begin");
    Cayenne.begin(username, password, clientID, SerialAT, apn, gprsUser, gprsPass, simPIN);

}

void loop() {
  SerialMon.println("Entering loop and calling Cayenne.loop");
  Cayenne.loop();
}

// Default function for sending sensor data at intervals to Cayenne.
// You can also use functions for specific channels, e.g CAYENNE_OUT(1) for sending channel 1 data.
CAYENNE_OUT_DEFAULT()
{
int signal_str = signal_strength();
bme.begin();
delay(100);

double temperature = 0;
double tempsum = 0;
for (int i = 0; i < 10; i++)
{
    tempsum = bme.readTemperature();
    delay(10);
    temperature = tempsum + temperature;
}
temperature = temperature / 10;

double humidity = 0;
double humiditysum = 0;
for (int i = 0; i < 10; i++)
{
    humiditysum = bme.readHumidity();
    humidity = humiditysum + humidity;
    delay(10);
}
humidity = humidity / 10;

double pressure = 0;
double pressuresum = 0;
  for (int i = 0; i < 10; i++)
  {
    pressuresum = bme.readPressure() / 100.0F;
    pressure = pressuresum + pressure;
    delay(10);
  }
pressure = pressure / 10;
double distance = determine_distance_5(temperature);
double batterylvl = getBatteryLevel();
SerialMon.print("Temperature: ");
SerialMon.print(temperature);
SerialMon.print("°C");
SerialMon.print(", Humidity: ");
SerialMon.print(humidity);
SerialMon.print("%RH");
SerialMon.print(", Pressure: ");
SerialMon.print(pressure);
SerialMon.print("hPa");
SerialMon.print(", Distance: ");
SerialMon.print(distance);
SerialMon.print("cm");
SerialMon.print(", Signal strength: ");
SerialMon.print(signal_str);
SerialMon.print(", Battery level: ");
SerialMon.print(batterylvl);
SerialMon.println("%");
SerialMon.println("Transmitting...");
  // Write data to Cayenne here. This example just sends the current uptime in milliseconds on virtual channel 0.
Cayenne.virtualWrite(0, temperature, "temp", "c");
Cayenne.virtualWrite(1, signal_str, "signal", "null");
Cayenne.virtualWrite(2, distance, "analog_sensor", "null");
Cayenne.virtualWrite(3, humidity, "rel_hum", "p");
Cayenne.virtualWrite(4, (double)(pressure), "bp", "hpa");
Cayenne.virtualWrite(5, (double)(batterylvl), "batt", "p");
delay(3000);
modem.gprsDisconnect();
SerialMon.println(F("GPRS disconnected"));
//After all off
modem.poweroff();
SerialMon.println(F("Poweroff"));
esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
esp_deep_sleep_start();
}

CAYENNE_CONNECTED() {
  connected_ = true;
  Serial.println("I am connected to Cayenne");
}

CAYENNE_DISCONNECTED() {
  connected_ = false;
  Serial.println("I am DISconnected from Cayenne");
}

// Default function for processing actuator commands from the Cayenne Dashboard.
// You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands.
CAYENNE_IN_DEFAULT()
{
  CAYENNE_LOG("Channel %u, value %s", request.channel, getValue.asString());
  //Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError("Error message");
}


// Reading the network signal 
int signal_strength() {
  int csq = modem.getSignalQuality();
  delay(500);
  Serial.print("Signal quality:");
  Serial.println(csq);
  return (int) (csq);
}


double getBatteryLevel()
{
  Wire.beginTransmission(0x75);
  Wire.write(0x78);
  if (Wire.endTransmission(false) == 0
   && Wire.requestFrom(0x75, 1)) {
    switch (Wire.read() & 0xF0) {
    case 0xE0: return 25;
    case 0xC0: return 50;
    case 0x80: return 75;
    case 0x00: return 100;
    default: return 0;
    }
  }
  return -1;
}

double determine_distance_5(double temperature) {
  calculate_distance_5(temperature);
  int ok_index = 0;
  double deviation = 0.5;
  double val_ = 0;
  float average_ = getAverage(distance_array_5, ARRAY_SIZE);
  average_ = 11.93 + 1.0819 * average_;
  float std_dev = getStdDev(distance_array_5, ARRAY_SIZE, average_);
  std_dev = 11.93 + 1.0819 * std_dev;
  Serial.print("AVG distance: "); Serial.print(average_); Serial.println(" cm");
  Serial.print("STD distance: "); Serial.print(std_dev); Serial.println(" cm");
  return average_;
}

float getAverage(double * val, int arrayCount) {
  long total = 0;
  for (int i = 0; i < arrayCount; i++) {
    total += val[i];
  }
  return total / float(arrayCount);
}


float getStdDev(double * val, int arrayCount, double avrg) {
  float avg = avrg;
  long total = 0;
  for (int i = 0; i < arrayCount; i++) {
    total = total + (val[i] - avg) * (val[i] - avg);
  }

  float variance = total / (float)arrayCount;
  float stdDev = sqrt(variance);
  return stdDev;
}

double calculate_distance_5(double temperature) {
  Serial.println("Starting with the US sensor measurement ");
  for (int i = 0; i < ARRAY_SIZE - 1; i++) {
    distance_array_5[i] = calculateDistanceUS_5(temperature);
    delay(50);
  }
}

double calculateDistanceUS_5(double temperature) {
  digitalWrite(enable_5, HIGH);
  delay(10);
  float adc = (analogRead(ANALOG_PIN_0) / 4096.0) * 3385.0;
  float distance_20 = (adc / 3385.0) * 500; //distance in cm
  float coeff = (sqrt(temperature + 273.15) / 17.12);
  float distance_compansated = distance_20 * coeff;
  digitalWrite(enable_5, LOW);
  return (double)(distance_20);
}

[eevorathemaster]

Hello I'm using the same TTGO board as you, without the battery, with a HILINK PSU and after 11 days it freezed, is the first time that I've seen this, did you manage to solve the problem? In case it continues doing this I would suggest an external Wachdog IC managed by interruptions. I hope that we don't need to go this way, and that the esp32 internal WDT will be able of solving this problem...