SIM800L is not working after disconnecting with PC

[rafitc99]

I'm trying to send some and receive SMS using SIM800L. After checking using Arduino Serial monitor all worked well. But after connecting on a PerfBoard using ATMEGA328 and clock circuit. It not sending/ receiving SMS. But the same while connecting with PC and open serial monitor It's working properly. Why this is occurring?

Some messages are sent But it was some blank messages.
I'm powering SIM800L through DC-DC buck Convertors .So, no way to issues with power. Not adding my messy code Right Now. If you wanna look at code too for a solution. Let me know.
Thanks in advance.

[salmanfaris]

@rafitc99 Can you share code and buck booster you are using?

[rafitc99]

@salmanfaris
I'm using LM2596 buck converter.

Following this setup

[salmanfaris]

@rafitc99 Can you share your code too!

[rafitc99]

@salmanfaris
This is my messy code.

#include <SoftwareSerial.h>
//#include <avr/wdt.h>

//Create software serial object to communicate with SIM800L
SoftwareSerial mySerial(9, 2); //SIM800L Tx & Rx is connected to Arduino #3 & #2

String content = "";
int Pulses = 3; //connect water flow sensor
volatile int pulsecount; //Variable to count number of pulses
unsigned long curr, prev, interval = 5000;
int led = 11;

long count = 0;
unsigned long onCall_prev_time, onCall_interval = 15000;
unsigned long timer;
bool ledFlag = 0;
bool smsFlag = 0; // sms flag
bool ackFlag = 0; //acknowledge flag
bool ackFlag_1 = 0; //acknowledge flag
bool recSmsFlag = 0; //Receive SmS flag
int statusAck = 0;
bool onCall_flag = 0; //to check call status
int c = 0;
bool terminate_flag = 0; //Flag to terminate whole event

bool terminate_flag_1 = 0; //Flag to terminate whole event

String number_1 = "YYxxxxxxxxxx";
  String number_2 = "YYxxxxxxxxxx";
  String number_3 = "YYxxxxxxxxxx";
  String number_4 = "YYxxxxxxxxxx";
  String test = "YYxxxxxxxxxx";
  String userName;

void setup() {
  pinMode(led, OUTPUT);
  
  pinMode(Pulses, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(Pulses), CountPulses, FALLING);
  //Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
  Serial.begin(9600);
  //Begin serial communication with Arduino and SIM800L
  mySerial.begin(9600);
  Serial.println("Initializing...");
  delay(500);
  Serial.println("Watchdog Enabled ");
  mySerial.println("AT+IPR=9600");
  updateSerial();
  //wdt_enable(WDTO_8S);
}

void updateSerial()
{
  //wdt_reset();
  detachInterrupt(CountPulses);
  delay(500);
  while (Serial.available())
  {
    mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
  }
  while (mySerial.available())
  {
    Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
  }
 
}

void recSerial()
{
  String msg;
  detachInterrupt(CountPulses);
  delay(500);
  while (Serial.available())
  {
    mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
  }
  while (mySerial.available())
  {
    detachInterrupt(CountPulses);
    msg = mySerial.readString();//Forward what Software Serial received to Serial Port
    processMsg(msg);
  }
}


void loop() {
  //wdt_reset();
  Serial.println("Loop strated----++++---++");
  
  pulsecount = 0;  //Start counting from 0 again
  interrupts();    //Enables interrupt on arduino pin 3
  delay(1000);
  detachInterrupt(CountPulses);
  //Calculating the water flow rate in Milli Liters per minute
  long flowRate;
  flowRate = (pulsecount * 2.22 * 60);
  Serial.print("Flow rate=");
  Serial.print(flowRate);   //Print milli liters per minute on serial monitor
  Serial.println("mL/minute");
  recSerial();
  digitalWrite(led, ledFlag); //Set or reset led based on the flow

  if (ackFlag_1) {
    Serial.println("Acknowledge Received-----------------------");
    content = "ACK received from " + userName +" paused all notifications ";
    smsSend_5(content);
    ackFlag_1 = false;
  }
 
  if (terminate_flag_1) {
    content = "GOT 'TERMINATE' From "+userName;
    smsSend_5(content);
    terminate_flag_1 = false;
  }
  
  if (onCall_flag) {
    Serial.println(c++);
    if (c >= 15) {
      Serial.println("Calling Event Completed");
      mySerial.println("ATH");
      updateSerial();
      onCall_flag = false;
      c = 0;
    }
  }
  if (statusAck) {
    if (pulsecount != 0) {
      smsSend_5("No problem. it's working perfectly!");
      statusAck = 0;
    }
    else if (pulsecount == 0) {
      smsSend_5("It's Not working!!!!");
      statusAck = 0;
    }
  }

  if (!recSmsFlag) {
    Serial.println("Setting into Receive Mode");
    recMode();
    recSmsFlag = true;
  }

  if (flowRate > 1) {
    Serial.println("Reseted all countors for new event ---++");
    count = 0; //Reset countor
    prev = 0; //reset timer;
    ackFlag = false; //reset ACK flags
    smsFlag = false; //Sent sms flag
    terminate_flag = false; //Reset Terminate flag
    ledFlag = 1; //Set LED Flag
  }

  if (flowRate == 0.00) {
    curr = millis();
    Serial.println("flowrate is Zero!!");
    ledFlag = 0; //Reset flag
    //wdt_reset();
    Serial.println("Reseted Watchdog");
    
    if (curr - prev >= 1000) {
      prev = curr;
      Serial.print(count++);
      Serial.println(" Seconds");

      if (count == 30 && ackFlag == 0) {
        Serial.println("ALERT 1 - FLow not working for 30 Seconds");
        //ackFlag = 0;
        smsSend_5("Flow is Zero about 30 Seconds!!!");
        smsFlag = true; //set sms flag
        //Send To other number too!
        //wdt_reset();
        Serial.println("Reseted Watchdog");
        //Send SMS
        
      }
      
      if (count == 40 && ackFlag == 0) {
        Serial.println("ALERT 1 - FLow not working for 40 Seconds");
        //ackFlag = 0;
        //smsSend_5("Flow is Zero about 40 Seconds!!!");
        smsFlag = true; //set sms flag
        //Send To other number too!
        //wdt_reset();
        makeCall(test);
        onCall_flag = 1;
        Serial.println("Reseted Watchdog");
        //Send SMS
      }
      if (count == 50 && ackFlag == 0) {
        Serial.println("ALERT 1 - FLow not working for 50 Seconds");
        //ackFlag = 0;
        smsSend_5("Flow is Zero about 30 Seconds!!!");
        smsFlag = true; //set sms flag
        //Send To other number too!
        //wdt_reset();
        Serial.println("Reseted Watchdog");
        //Send SMS
      }
      if (count == 60 && ackFlag == 0) {
        Serial.println("ALERT 1 - FLow not working for 60 Seconds");
        //ackFlag = 0;
        smsSend_5("Flow is Zero about 30 Seconds!!!");
        smsFlag = true; //set sms flag
        //Send To other number too!
        //wdt_reset();
        Serial.println("Reseted Watchdog");
        //Send SMS
      }
      if (count == 90 && ackFlag == 0) {
        Serial.println("Not working for 1.5 minutes");
        makeCall(test);

        //smsSend();
        //SmS
        //wdt_reset();
        Serial.println("Reseted Watchdog");
      }
      if (count == 150 && ackFlag == 0) {
        Serial.println("Not working for 2.5 minutes");
        //        makeCall(test); //make call to Number 2
        smsSend_5("Flow is Zero about 2.5 Minutes!!!");
        //smsSend(number_2,"Flow is Zero about 2.5 Minutes!!!");
        //smsSend(number_3,"Flow is Zero about 2.5 Minutes!!!");
        //smsSend(number_4,"Flow is Zero about 2.5 Minutes!!!");
        //SmS
        //wdt_reset();
        Serial.println("Reseted Watchdog");
      }
      if (count == 210 && ackFlag == 0) {
        Serial.println("Not working for 3.5 minutes");
        smsSend_5("Flow is Zero about 3.5 Minutes!!!");
//        makeCall(number_1); //make call to Number 3
        //smsSend();
        //wdt_reset();
        Serial.println("Reseted Watchdog");
        //SmS
      }
      if (count == 270 && ackFlag == 0) {
        Serial.println("Not working for 4.5 minutes");
        smsSend_5("Flow is Zero about 4.5 Minutes!!!");
        //        makeCall(number_2); //make call to Number 4
        //smsSend();
        //SmS
      }
      if (count == 180 && terminate_flag == 0) {
        Serial.println("just a reminder");
        smsSend_5("Blower is not working more than 8 minutes");
       // smsSend_5("It's been 8+ Minutes Your blower is not working.");
        //smsSend(number_3,"It's been 8+ Minutes Your blower is not working. Hope Now, You are working on that ;)");
        //smsSend(number_4,"It's been 8+ Minutes Your blower is not working. Hope Now, You are working on that ;)");
      }
      if (count >= 600 && terminate_flag == 0) {
        Serial.println("DANGER!!!");
        smsSend_5("DANGER!! Flow is Not working more than 10 Minutes!!!");
        count = 0;
        ///SmS
      }
    }
  }
} 

void CountPulses()
{
  pulsecount++; //Increment the variable on every pulse
}
void recMode(){
  Serial.println("Setting Recieve mode");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1");
  updateSerial();
  mySerial.println("AT+CNMI=1,2,0,0,0");
  updateSerial();
}

void smsSend_1(String content) {
  
  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}

void smsSend_2(String content) {
  //wdt_reset();
  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}


void smsSend_3(String content) {
  
  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}


void smsSend_4(String content) {
  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}


void smsSend_5(String content) {

  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
  
}
void makeCall(String number1) {
  
  detachInterrupt(CountPulses);
  recSmsFlag = 0; //Reset Rec SMS flag
  mySerial.print (F("ATD"));
  mySerial.print (number1);
  mySerial.print (F(";\r\n"));
  updateSerial();
  onCall_prev_time = millis();
  Serial.print("----Calling to ");
  Serial.println(number1);
  onCall_flag = true;
  //delay(15000);

}
String getName(String nameOfuser) {
  String user;
  detachInterrupt(CountPulses);
  Serial.print("Get Name is Running ----------");

    if(nameOfuser.indexOf(number_1)>0){
    user = "Rashad"; //name of first user
    return user;
    }
    else if(nameOfuser.indexOf(number_2)>0){
    user = "Hashim"; //name of second user
    return user;
    }
    else if(nameOfuser.indexOf(number_3)>0){
    user = "Rasil"; //name of third user
    return user;
    }
    else if(nameOfuser.indexOf(number_4)>0){
    user = "Anas"; //name of fourth user
    return user;
    }
    else if(nameOfuser.indexOf(test)>0){
    user="Rafi";
    return user;
    }
    else{
      user = "Unknown";
      return user;
    }
}
void processMsg(String msg){
  Serial.print(msg);
  detachInterrupt(CountPulses);
  Serial.println("process started!!!!!----------");
  digitalWrite(11,1);
  delay(500);
  digitalWrite(11,0);
  if ((msg.indexOf("Stop")>0)) {
      Serial.print("Got ACK from------ ");
      //wdt_reset();
      Serial.println("Reseted Watchdog");
      userName = getName(msg);
      ackFlag_1 = 1;
      ackFlag = 1;
    }
    else if ((msg.indexOf("Check")>0)) {
//      detachInterrupt(CountPulses);
      Serial.println("Status Test MSG Received --------");
      userName = getName(msg);
      statusAck = 1;
    }
    else if ((msg.indexOf("Terminate") > 0)) {
//      detachInterrupt(CountPulses);
      userName = getName(msg);
      Serial.print("Terminated all notification until next event by ");
      //Serial.println(userName);
      // wdt_reset();
      Serial.println("Reseted Watchdog");  
      terminate_flag_1 = 1;
      terminate_flag = 1;
   }
   else{
    Serial.println("Not a admin commend ");
   }
}

[salmanfaris]

Hi @rafitc99, May I know why you are using this same function definition with different function name?

void smsSend_1(String content) {

  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}

void smsSend_2(String content) {
  //wdt_reset();
  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}

void smsSend_3(String content) {

  detachInterrupt(CountPulses);
  Serial.println("SMS sending");
  mySerial.println("AT");
  updateSerial();
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  updateSerial();
  mySerial.println("AT+CMGS=\"+ YYxxxxxxxxxx\"");//("AT+CMGS=\"" +number+ "\""); //change ZZ with country code and xxxxxxxxxxx with phone number to sms
  updateSerial();
  mySerial.print(content); //text content
  updateSerial();
  mySerial.write(26);
  Serial.println("sent!!");
  recSmsFlag = false; //Reset Rec SMS flag
}

[rafitc99]

@salmanfaris
Sorry, leave that part
Actually I was using ("AT+CMGS=\"" +number+ "\""); this part and passing number into the funciton. This different functions all are done part of debugging. just checking Is there any problem in string handling.

[salmanfaris]

@rafitc99 Ok, are you connecting all the ground as common in the circuit when using the LM2596 buck converter to power up the module/Arduino? and check the resistor that you are using stepdown Tx signal from Arduino to the SIM800L.!

[rafitc99]

@salmanfaris Yes. I'm providing common ground. Resistors also working.

[salmanfaris]

@rafitc99 Great, can you try this simple code that only includes the SMS sending part! if it's working fine with and without the computer connection we can look it to the other parts!

#include <SoftwareSerial.h>

//Create software serial object to communicate with SIM800L
SoftwareSerial mySerial(3, 2); //SIM800L Tx & Rx is connected to Arduino #3 & #2

void setup()
{
  //Begin serial communication with Arduino and Arduino IDE (Serial Monitor)
  Serial.begin(9600);

  //Begin serial communication with Arduino and SIM800L
  mySerial.begin(9600);

  Serial.println("Initializing...");
  delay(1000);


}

void loop()
{

  mySerial.println("AT"); //Once the handshake test is successful, it will back to OK
  mySerial.println("AT+CMGF=1"); // Configuring TEXT mode
  mySerial.println("AT+CMGS=\"+ZZxxxxxxxxxx\"");//change ZZ with country code and xxxxxxxxxxx with phone number to sms
  mySerial.print("SMS Test "); //text content
  updateSerial();
  mySerial.write(26);

  delay(7000);

}