TTGO T-Call ESP32 SIM800L cannot be connected with the Blynk cloud

joeljacob98 · September 17, 2021, 9:05am

Hello everybody in the Blynk.Community,

I am currently using the TTGO T-Call ESP32 SIM800L device and it can’t seem to be connected to the Blynk cloud.

The coding, fortunately, can be uploaded into the device but the cloud/dashboard is still waiting for the device to be connected.

I have used the Blynk > Boards_GSM > TinyGSM_SIM800_SIM900 example that is in the Arduino IDE.

This is my coding:

#define BLYNK_PRINT Serial

/* Fill-in your Template ID (only if using Blynk.Cloud) */
#define BLYNK_TEMPLATE_ID "TMPLDAg-UKvi"
#define BLYNK_DEVICE_NAME "Quickstart Device"
#define BLYNK_AUTH_TOKEN "jCIBo3HvkieM6NBzqhM1QlZJbA45F8wC";

// Please select the corresponding model
#define SIM800L_IP5306_VERSION_20190610

// Select your modem:
#define TINY_GSM_MODEM_SIM800

// Default heartbeat interval for GSM is 60
// If you want override this value, uncomment and set this option:
// #define BLYNK_HEARTBEAT 30

#include <TinyGsmClient.h>
#include <BlynkSimpleTinyGSM.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "jCIBo3HvkieM6NBzqhM1QlZJbA45F8wC";

// Your GPRS credentials
// Leave empty, if missing user or pass
char apn[]  = "celcom.net.my";
char user[] = "";
char pass[] = "";

// Hardware Serial on Mega, Leonardo, Micro
#define SerialAT Serial1

// Set serial for debug console (to the Serial Monitor, default speed 115200)
#define SerialMon Serial

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

// or Software Serial on Uno, Nano
//#include <SoftwareSerial.h>
//SoftwareSerial SerialAT(2, 3); // RX, TX

#include "utilities.h"

#define relay1 18
#define relay2 14
#define relay3 15
#define relay4 19

#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, SerialMon);
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif
TinyGsmClient client(modem);

BLYNK_WRITE(V0)
{
  int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
  digitalWrite(relay1, !pinValue);
  delay(1000);
  // process received value
}

BLYNK_WRITE(V1)
{
  int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
  digitalWrite(relay2, !pinValue);
  // process received value
}

BLYNK_WRITE(V2)
{
  int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
  digitalWrite(relay3, !pinValue);
  // process received value
}

BLYNK_WRITE(V3)
{
  int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
  digitalWrite(relay4, !pinValue);
  // process received value
}

void setup()
{
  // Debug console
  Serial.begin(115200);

  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(relay3, OUTPUT);
  pinMode(relay4, OUTPUT);

  digitalWrite(relay1, HIGH);
  digitalWrite(relay2, HIGH);
  digitalWrite(relay3, HIGH);
  digitalWrite(relay4, HIGH);
  
  delay(10);

  setupModem();

  SerialMon.println("Wait...");

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

  delay(6000);

  // Restart takes quite some time
  // To skip it, call init() instead of restart()
  SerialMon.println("Initializing modem...");
   modem.restart();
  // modem.init();

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

  // Unlock your SIM card with a PIN
  //modem.simUnlock("1234");
  
  Blynk.begin(auth, modem, apn, user, pass);
}

void loop()
{
  Blynk.run();
}

utilities.h coding:

#include <Wire.h>

#if defined(SIM800L_IP5306_VERSION_20190610)

#define MODEM_RST             5
#define MODEM_PWRKEY          4
#define MODEM_POWER_ON       23
#define MODEM_TX             27
#define MODEM_RX             26

#define I2C_SDA              21
#define I2C_SCL              22
#define LED_GPIO             13
#define LED_ON               HIGH
#define LED_OFF              LOW

#define IP5306_ADDR          0x75
#define IP5306_REG_SYS_CTL0  0x00

// setPowerBoostKeepOn
bool setupPMU()
{
    bool en = true;
    Wire.begin(I2C_SDA, I2C_SCL);
    Wire.beginTransmission(IP5306_ADDR);
    Wire.write(IP5306_REG_SYS_CTL0);
    if (en) {
        Wire.write(0x37); // Set bit1: 1 enable 0 disable boost keep on
    } else {
        Wire.write(0x35); // 0x37 is default reg value
    }
    return Wire.endTransmission() == 0;
}

#elif defined(SIM800L_AXP192_VERSION_20200327)

#define MODEM_RST            5
#define MODEM_PWRKEY          4
#define MODEM_POWER_ON       23
#define MODEM_TX             27
#define MODEM_RX             26
#define MODEM_DTR            32
#define MODEM_RI             33

#define I2C_SDA              21
#define I2C_SCL              22
#define LED_GPIO             13
#define LED_ON               HIGH
#define LED_OFF              LOW

#elif defined(SIM800C_AXP192_VERSION_20200609)
// pin definitions
#define MODEM_PWRKEY          4
#define MODEM_POWER_ON       25
#define MODEM_TX             27
#define MODEM_RX             26
#define MODEM_DTR            32
#define MODEM_RI             33

#define I2C_SDA              21
#define I2C_SCL              22
#define LED_GPIO             12
#define LED_ON               LOW
#define LED_OFF              HIGH

#elif defined(SIM800L_IP5306_VERSION_20200811)

#define MODEM_RST             5
#define MODEM_PWRKEY          4
#define MODEM_POWER_ON       23
#define MODEM_TX             27
#define MODEM_RX             26

#define MODEM_DTR            32
#define MODEM_RI             33

#define I2C_SDA              21
#define I2C_SCL              22
#define LED_GPIO             13
#define LED_ON               HIGH
#define LED_OFF              LOW

#define IP5306_ADDR          0x75
#define IP5306_REG_SYS_CTL0  0x00

// setPowerBoostKeepOn
bool setupPMU()
{
    bool en = true;
    Wire.begin(I2C_SDA, I2C_SCL);
    Wire.beginTransmission(IP5306_ADDR);
    Wire.write(IP5306_REG_SYS_CTL0);
    if (en) {
        Wire.write(0x37); // Set bit1: 1 enable 0 disable boost keep on
    } else {
        Wire.write(0x35); // 0x37 is default reg value
    }
    return Wire.endTransmission() == 0;
}

#else

#error "Please select the corresponding model"

#endif

#if defined(SIM800L_AXP192_VERSION_20200327) || defined(SIM800C_AXP192_VERSION_20200609)
#include <axp20x.h>         //https://github.com/lewisxhe/AXP202X_Library

AXP20X_Class axp;

bool setupPMU()
{
// For more information about the use of AXP192, please refer to AXP202X_Library https://github.com/lewisxhe/AXP202X_Library
    Wire.begin(I2C_SDA, I2C_SCL);
    int ret = axp.begin(Wire, AXP192_SLAVE_ADDRESS);

    if (ret == AXP_FAIL) {
        Serial.println("AXP Power begin failed");
        return false;
    }

    //! Turn off unused power
    axp.setPowerOutPut(AXP192_DCDC1, AXP202_OFF);
    axp.setPowerOutPut(AXP192_LDO2, AXP202_OFF);
    axp.setPowerOutPut(AXP192_LDO3, AXP202_OFF);
    axp.setPowerOutPut(AXP192_DCDC2, AXP202_OFF);
    axp.setPowerOutPut(AXP192_EXTEN, AXP202_OFF);

    //! Do not turn off DC3, it is powered by esp32
    // axp.setPowerOutPut(AXP192_DCDC3, AXP202_ON);

    // Set the charging indicator to turn off
    // Turn it off to save current consumption
    // axp.setChgLEDMode(AXP20X_LED_OFF);

    // Set the charging indicator to flash once per second
    // axp.setChgLEDMode(AXP20X_LED_BLINK_1HZ);

    //! Use axp192 adc get voltage info
    axp.adc1Enable(AXP202_VBUS_VOL_ADC1 | AXP202_VBUS_CUR_ADC1 | AXP202_BATT_CUR_ADC1 | AXP202_BATT_VOL_ADC1, true);

    float vbus_v = axp.getVbusVoltage();
    float vbus_c = axp.getVbusCurrent();
    float batt_v = axp.getBattVoltage();
    // axp.getBattPercentage();   // axp192 is not support percentage
    Serial.printf("VBUS:%.2f mV %.2f mA ,BATTERY: %.2f\n", vbus_v, vbus_c, batt_v);

    return true;
}

#endif

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

#ifdef MODEM_RST
    // Keep reset high
    pinMode(MODEM_RST, OUTPUT);
    digitalWrite(MODEM_RST, HIGH);
#endif

    pinMode(MODEM_PWRKEY, OUTPUT);
    pinMode(MODEM_POWER_ON, OUTPUT);

    // Turn on the Modem power first
    digitalWrite(MODEM_POWER_ON, HIGH);

    // Pull down PWRKEY for more than 1 second according to manual requirements
    digitalWrite(MODEM_PWRKEY, HIGH);
    delay(100);
    digitalWrite(MODEM_PWRKEY, LOW);
    delay(1000);
    digitalWrite(MODEM_PWRKEY, HIGH);

    // Initialize the indicator as an output
    pinMode(LED_GPIO, OUTPUT);
    digitalWrite(LED_GPIO, LED_OFF);
}

And this is what is being displayed in my serial monitor:

I would like to know what can I do to be able to connect this device with the Blynk cloud.
Thank you so much for your time and considerations.

PeteKnight · September 17, 2021, 9:50am

@joeljacob98 please edit your post, using the pencil icon at the bottom, and add triple backticks at the beginning and end of your code so that it displays correctly.
Triple backticks look like this:
```

Pete.

VIGHNESHNS2008 · September 17, 2021, 10:30am

me too face the same error

joeljacob98 · September 17, 2021, 10:39am

Thank you @PeteKnight for letting me know.

PeteKnight · September 17, 2021, 11:17am

Your mobile ISP may be blocking port 80, so you could try forcing the use of port 8080.

Pete.

joeljacob98 · September 18, 2021, 6:53am

Thank you Sir for taking the time in going through my coding. What should I do to force my device to use port 8080?

Joel.

PeteKnight · September 18, 2021, 12:03pm

Based on a quick search, I think the correct syntax is…

Blynk.begin(auth, modem, apn, user, pass, "blynk.cloud", 8080);

Pete.

Murray · September 19, 2021, 3:00pm

My TTGO T-Call is also having problems connecting to blynk.cloud or blynk-cloud.com on ports 80 or 8080 and I’m using wifi code that worked perfectly only a couple of days ago.

joeljacob98 · September 20, 2021, 7:29am

Thank you Sir, for your solution. I will give it a try and let you know whether it is working or not.

Joel.

joeljacob98 · September 20, 2021, 7:31am

Yes same here, I manage to connect the TTGO T-Call device to the blynk dashboard through WiFi but could not do it via GSM.

GarudaOne · September 20, 2021, 7:53am

My T-Call works normally. But I have problem with my A9 GPRS. At first my A9 GPRS worked, but a few days ago I face connection issue with my A9 GPRS. It’s due to DNS issue in resolving the blynk.cloud, I use direct IP address and it works.

Murray · September 20, 2021, 8:06am

Last night the TTGO connected through wifi again at first attempt. GSM connection also works. Sometimes the Blynk cloud just seems to become inaccessible. Will investigate the direct IP solution…

I’ve found that for GSM connection you can sometimes solve the Blynk connection problem by just moving/rotating the unit a bit for better reception.

FCS · September 20, 2021, 12:33pm

I am using LTE-M

Twillio IOT super sim works great for me.
No issues accessing networks. $2 pm and 10c per MB

joeljacob98 · September 21, 2021, 6:15am

Hello Sir, I have used your solution and uploaded the coding into my TTGO T-Call device and still it cannot be connected to the Blynk dashboard.

This is what is being shown in the serial monitor:

What else can I do, Sir?

Joel.

joeljacob98 · September 21, 2021, 6:24am

Hello @GarudaOne, thank you for taking your time in going through my problem.

I was wondering on which IP address that you used and how did you place it in your coding in enabling your device to be connected to the Blynk dashboard.

joeljacob98 · September 21, 2021, 6:28am

Hello @Murray and @FCS, thank you for your suggestions. I will try them out.

GarudaOne · September 21, 2021, 6:47am

I do this in Blynk Python library by overriding the library. You can do the same with the C++ version.
But as I said this is just a temporary workaround.

resolve the blynk.cloud to IP and update the library

joeljacob98 · September 21, 2021, 7:02am

Thank you @GarudaOne. I will look into it.

PeteKnight · September 21, 2021, 7:09am

Using the cloud server IP address in Blynk IoT isn’t the best solution. Instead you should use the full URL for the server that hosts your project.

Start by looking at the bottom right hand corner of your Blynk console browser screen, or the “About” screen in the app.

Then, look at this page of the documentation and find the full URL for the cloud server you use:

Replace "blynk.cloud" in your Blynk.begin command with the full URL.

Pete.

joeljacob98 · September 21, 2021, 7:11am

Thank you Sir. I will do that and let you know

Joel.