Problem in receiving sms correctly with sim800l

Using Arduino Programming Questions
1

Hello.
With a sim800l module and an arduino, I want to send an SMS to a specific number at a certain time of the day containing the information that an esp collects from a temperature and humidity sensor. The function of sending SMS is working correctly, but the message I receive is as follows:

Tå@A@É@ÑOÉ@éAT+CMGF=1
AT+CMGS="xxxxxxxxxx"
Temperature: 33.51
Humidity: 16.02
AC Connected

And this is the program:

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <SoftwareSerial.h>
//#include<ESP8266WebServer.h>
#include <PubSubClient.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266httpUpdate.h>
#include <WiFiClientSecure.h>
#include <time.h>




const String FirmwareVer={"1.4.7"}; 
#define URL_fw_Version "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
#define URL_fw_Bin "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
const char* host = "raw.githubusercontent.com";
const int httpsPort = 443;



#define rxPin D6
#define txPin D5
SoftwareSerial mySerial(rxPin,txPin);

#define ssid "Ang-Sim"
#define pass "qwerty2580"

//// UDP
WiFiUDP UDP;
IPAddress local_ip(192, 168, 100, 1);
IPAddress gateway(192, 168, 100, 1);
IPAddress subnet(255, 255, 255, 0);
#define UDP_PORT 4210

//ESP8266WebServer server(80);

const char* wifi = "SRV-TSC";
const char* password = "Cer@toLimited141";

const String prefix  = "/angizeh/toossab/1/4";
const char* mqtt_topic = "/angizeh/toossab/1/4";
const char* clientID = "AirHumidityNode12";

const char* mqttServerName = "xxxxxxxxxxxxx";
const int   mqttport = 1883;
const char* mqttuser =  "xxxxxxxxxxxxxxxxx";
const char* mqttpass =  "xxxxxxxxxxxxx";

WiFiClient wclient;                        
PubSubClient client(wclient);


String topic = "";
String message = "";
String message01,message02,  toDigit;
String getValue(String data, char separator, int index); 
float airTemperatureA = 0.0, airTemperatureB = 0.0 ,airTemperatureReal = 0.0, airHumidityA = 0.0,airHumidityB = 0.0, airHumidityReal = 0.0;
int dataA , dataReal;

// UDP Buffer
char packet[255];
char reply[] = "Packet received!";
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];
int ACState = 1;
int newACState = 1;
int cnt=10;
int cnt2=10;
int nodeDisconnectCnt=2;
int timezone = 4.5 * 3600 ;
int dst = 0;
int hour;
int minute;
int second;
int trigger = 1;
static unsigned long timer4 = millis();
//static unsigned long timer3 = millis();
static unsigned long timer2 = millis();
//static unsigned long timer = millis();
const String PHONE = "9xxxxxxxxxxx";
const String PHONE2 = "9xxxxxxxxxxx";




void setup()
{
  delay(1300);
  //ESP.wdtEnable(0); 
   // Setup serial port
  Serial.begin(115200);
  Serial.println();
  // Begin Access Point
  Serial.println("UDP server\nStarting access point...");
  WiFi.mode(WIFI_AP_STA);
  WiFi.softAPConfig(local_ip, gateway, subnet);
  WiFi.softAP(ssid, pass);
  IPAddress myIP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(myIP); 
  // Begin listening to UDP port
  UDP.begin(UDP_PORT);
  Serial.print("Listening on UDP port ");
  Serial.println(UDP_PORT); 
  STA();
  configTime(timezone, dst, "pool.ntp.org","time.nist.gov");
  //پیکربندی ارتباط سریال ماژول
  mySerial.begin(9600);

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

  mySerial.begin(9600);                                 //Define boadrate of serial communication 
  mySerial.println("AT+CMGF=1");

  delay(2000);
}

void loop()
{
   time_t now = time(nullptr);
  struct tm* p_tm = localtime(&now);
  hour = p_tm->tm_hour;
  minute = p_tm->tm_min;
  second = p_tm->tm_sec;
if (hour == 18 && minute == 59 && second == 0) {
  sendingData();
  trigger = 0;
}
if (hour == 19 && minute == 6 && 15>second>0) {
  if (trigger = 1){
  trigger = 0;
  sendingData();
  }
}

if (hour == 23 && minute == 59) {
  trigger = 1;
}

  if (WiFi.status() == WL_CONNECTED){
//  server.handleClient();
 ESP.wdtFeed();

   if (millis() - timer4 > 60000) { 
        repeatedCall();    
        timer4 = millis();
   }
    if (!client.connected()){
     reconnect(); 
      }else{
    


  packet[0] = '\0';
  receiveUDP();
  delay(1000);
 if (getValue(packet,',',0) == "nodeA") {
      Serial.print("Message is: "); Serial.println("Node A");
      message02 = packet;
//      Serial.println(packet);
//      Serial.print("12");
//      Serial.print(",");     
      Serial.print("Temperature: "); 
      Serial.println(getValue(message02,',',1));
      toDigit = getValue(message02,',',1);
      airTemperatureReal = toDigit.toFloat();
      if (airTemperatureA != airTemperatureReal){
        airTemperatureA = airTemperatureReal;
       dataPublish();       
        Serial.println("Published");
      }
      Serial.print("Humidity: "); 
      Serial.println(getValue(message02,',',2));
      toDigit = getValue(message02,',',2);
      airHumidityReal = toDigit.toFloat();
      if (airHumidityA != airHumidityReal){
      airHumidityA = airHumidityReal;
       timer2 = millis();
       dataPublish();
          
       // client.publish(toCharArray("/angizeh/toossab/1/4/Humidity"), toCharArray(String(airHumidityA)));
        Serial.println("Published");
      }
      Serial.println(getValue(message02,',',3));
     toDigit = getValue(message02,',',3);
     if (toDigit.length() > 0)
     {
        dataReal = toDigit.toFloat();
        dataA = dataReal;
        newACState = dataA;
        Serial.println("Humidity Published");
     }
 
      if (ACState != newACState){
        ACState = newACState;
        Serial.println("UDP packet received ");
        if (ACState == 1){
        //client.publish(toCharArray("/angizeh/toossab/1/4/SMSSending"), toCharArray("Sending SMS 1")); 
        
         phone1Config();

        mySerial.print("AC Connected"); //محتوای ارسالی
        delay(100);
       mySerial.write(0x1A);
        Serial.println ("AC Connected");
       delay(5000);
       
           phone2Config();
           
        mySerial.print("AC Connected"); //محتوای ارسالی
        delay(100);
        mySerial.write(0x1A);
        Serial.println ("AC Connected");
        delay(1000);

       
      }
      if (ACState == 0) {
        // client.publish(toCharArray("/angizeh/toossab/1/4/SMSSending"), toCharArray("Sending SMS 0")); 
         
           phone1Config();

        mySerial.print("AC Disconnected"); //محتوای ارسالی
        delay(100);
       mySerial.write(0x1A);
       Serial.println ("AC Disconnected");
       delay(5000);
       
        phone2Config();
        
        mySerial.print("AC Disconnected"); //محتوای ارسالی
        delay(100);
        mySerial.write(0x1A);
        Serial.println ("AC Disconnected");
        delay(1000);
      }
     }
 }
 else {
  
      client.publish(toCharArray("/angizeh/toossab/1/4/nodeAState"), toCharArray("Disconnected")); 
     dataPublish();
  } 
}
 
   Serial.printf("Available RAM: %d\n", ESP.getFreeHeap());
  //updateSerial();   
 } else{
  Serial.println("no connection");
        checkWifi();
      }
  yield();
}

void updateSerial()
{
  delay(500);
  while (Serial.available()) 
  {
    mySerial.write(Serial.read());//هرچه در سریال مانیتور نوشته شود به ماژول ارسال میشود
  }
  while(mySerial.available()) 
  {
    Serial.write(mySerial.read());//هرچه از ماژول دریافت شود در سریال مانیتور نوشته میشود
  }
}

void STA()
{
      WiFi.begin(wifi, password);

     while (WiFi.status() != WL_CONNECTED){
   static unsigned long connectionTimer = millis();                     
    delay(100);
    Serial.print(".");
    if (millis() - connectionTimer > 15000){
      connectionTimer = millis();
      ESP.wdtEnable(0);  
    while(1);  
   }
  }

      Serial.println();

      Serial.print(".....Connect to the WiFi and open the IP address given below.....");
      Serial.println("IP address:-");
      Serial.println(WiFi.localIP());

//      server.on ("/", [] () {server.send(200, "text/plain", "HELLO THERE");});
//      server.begin();

Serial.print("connecting...");
      client.setServer(mqttServerName, mqttport);
  client.setCallback(onMessageArrived);
//  
 while (!client.connected()){
    delay(1000);
    Serial.println("Connecting To Server ...");
 
    if (client.connect(clientID, mqttuser, mqttpass, toCharArray(prefix + "/Will"), 1, true, toCharArray("Bye"), true))
    {
      Serial.println("Connected To Server");
    } 
    else 
    {
      Serial.print("failed with state ");
      Serial.print(client.state());
      delay(2000);
      break;
    }
  }
    client.publish(toCharArray("/angizeh/toossab/1/4/ESPState"), toCharArray("turn on")); 
}


char* toCharArray(String str) {
  return &str[0];
}

void onMessageArrived(char* t, byte* m, unsigned int length) {
  topic = String(t);
  message = String((char*)m);
  message = message.substring(0, length);

  if (message == "HELLO") {
    Serial.println("Hello client");
    Serial.println("Hello server");
  }
}


void reconnect() {  
  client.setServer(mqttServerName, mqttport);
  client.setCallback(onMessageArrived);
  if (!client.connected()) { 
    while (!client.connected()) { 
      Serial.print("MQTT.."); 
      delay(1000); 
      if (client.connect(clientID, mqttuser, mqttpass, toCharArray(prefix + "/Will"), 1, true, toCharArray("Disconnected"), true)) { 
        client.setCallback(onMessageArrived);
        Serial.println("MQTT connected");           
      } else { error(); } 
    }  
  }
   
  client.loop(); 

  delay(1000);
}

void error() {  Serial.print("failed, rc=");      Serial.print(client.state());      Serial.println(" try again in 5 seconds");      delay(5000);   }


void receiveUDP(){
 int packetSize = UDP.parsePacket();
  if (packetSize) {
    Serial.print("Received packet! Size: ");
    Serial.println(packetSize); 
    int len = UDP.read(packet, 255);
    if (len > 0){
      packet[len] = '\0';
    }
    Serial.print("Packet received: ");
    Serial.println(packet);
  }
  for(int i=0;i<UDP_TX_PACKET_MAX_SIZE;i++) packetBuffer[i] = 0;
}

String getValue (String data, char separator, int index) {
    int found = 0;
    int strIndex[] = { 0, -1 };
    int maxIndex = data.length();

    for (int i = 0; i <= maxIndex && found <= index; i ++) {
        if (data.charAt(i) == separator || i == maxIndex) {
            found ++;
            strIndex[0] = strIndex[1] + 1;
            strIndex[1] = (i == maxIndex) ? i + 1 : i;
        }
    }
    return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
}

void dataPublish (){
  if (!client.connected()) {
 
  reconnect();
  } else {
 client.publish(toCharArray("/angizeh/toossab/1/4/Temperature"), toCharArray(String(airTemperatureA)));
 client.publish(toCharArray("/angizeh/toossab/1/4/Humidity"), toCharArray(String(airHumidityA)));
  if (dataA == 1){
        client.publish(toCharArray("/angizeh/toossab/1/4/ACPower"), toCharArray("1"));  
        }
        if (dataA == 0){
        client.publish(toCharArray("/angizeh/toossab/1/4/ACPower"), toCharArray("0"));  
        }
}
}

void FirmwareUpdate()
{  
  WiFiClientSecure client;
   client.setInsecure();
  if (!client.connect(host, httpsPort)) {
    Serial.println("Connection failed");
    return;
  }
  client.print(String("GET ") + URL_fw_Version + " HTTP/1.1\r\n" +
               "Host: " + host + "\r\n" +
               "User-Agent: BuildFailureDetectorESP8266\r\n" +
               "Connection: close\r\n\r\n");
  while (client.connected()) {
    String line = client.readStringUntil('\n');
    if (line == "\r") {
      //Serial.println("Headers received");
      break;
    }
  }
  String payload = client.readStringUntil('\n');

  payload.trim();
  if(payload.equals(FirmwareVer) )
  {   
     Serial.println("Device already on latest firmware version "+FirmwareVer); 
  }
  else
  {
    Serial.println("New firmware detected");
    ESPhttpUpdate.setLedPin(LED_BUILTIN, LOW); 
    t_httpUpdate_return ret = ESPhttpUpdate.update(client, URL_fw_Bin);
        
    switch (ret) {
      case HTTP_UPDATE_FAILED:
        Serial.printf("HTTP_UPDATE_FAILD Error (%d): %s\n", ESPhttpUpdate.getLastError(), ESPhttpUpdate.getLastErrorString().c_str());
        break;

      case HTTP_UPDATE_NO_UPDATES:
        Serial.println("HTTP_UPDATE_NO_UPDATES");
        break;

      case HTTP_UPDATE_OK:
        Serial.println("HTTP_UPDATE_OK");
        break;
    } 
  }
 }
 
 void repeatedCall(){
  
   
      // save the last time you blinked the LED

      FirmwareUpdate();
    
 }


 void checkWifi (){

   while (WiFi.status() != WL_CONNECTED){
    ESP.wdtFeed();            
    ESP.wdtDisable();                     
    delay(500);
    Serial.print(".");
    delay(500);
    cnt--;
    if(cnt==0){
    ESP.wdtDisable();
    #ifdef SOFT_WATCHDOG
    ESP.wdtEnable(0);
    #endif  
    while(1);
  }
}
}

void sendingData(){
  
  phone1Config();
  
        mySerial.print("Temperature: ");
        delay(100);
        mySerial.println(airTemperatureReal); //محتوای ارسالی
        delay(100);
        mySerial.print("Humidity: ");
        delay(100);
        mySerial.println(airHumidityReal);
        delay(100);
         if (dataA == 1){
          mySerial.print("AC Connected");
         }
          if (dataA == 0){
          mySerial.print("AC Disconnected");
         }
       mySerial.write(0x1A);
       delay(5000);
        Serial.println ("AC Connected");
        
  phone2Config();
  
        mySerial.print("Temperature: ");
        delay(100);
        mySerial.println(airTemperatureReal); //محتوای ارسالی
        delay(100);
        mySerial.print("Humidity: ");
        delay(100);
        mySerial.println(airHumidityReal);
        delay(100);
         if (dataA == 1){
          mySerial.print("AC Connected");
         }
          if (dataA == 0){
          mySerial.print("AC Disconnected");
         }
       mySerial.write(0x1A);
       delay(1000);
        Serial.println ("AC Connected");
}

void phone1Config (){
   mySerial.print("AT+CMGF=1\r");
           delay(1000);
        //client.publish(toCharArray("/angizeh/toossab/1/4/ACPower"), toCharArray("Disconnected"));
        mySerial.print("AT+CMGS=\""+PHONE+"\"\r");
        delay(500);
}

void phone2Config (){
   mySerial.print("AT+CMGF=1\r");
           delay(1000);
        //client.publish(toCharArray("/angizeh/toossab/1/4/ACPower"), toCharArray("Disconnected"));
        mySerial.print("AT+CMGS=\""+PHONE2+"\"\r");
        delay(500);
}

Sometimes the correct SMS is sent, but sometimes it arrives as above. I had this problem many times with sim800 but I could not solve it. Thank you for your guidance.

2

The most common problem with the SIM800 modules is that they are not supplied with enough current at the correct voltage. How is yours powered ?

3

I provided 4.4V 2A for the module. The module has no problem connecting to the network. The current peak in sim800 is usually at the time of connection to the network.

4

Looked at the code...
Delays during the reception of data on the Serial make it unlikely that the data will be received correctly. Your code is simply clogged with delays in all procedures. This one:

here is just a shot in the foot. For half a second, even at a speed of 9600, the Serial can take about 500 characters. And its input buffer is only 64 bytes. This means that you will lose most of the message.
The first thing you need to do is remove all delays longer than 10 ms from the code

And this is an incorrect syntax:

5

Which type of ESP? Do you have to really use SoftwareSerial? Couldn’t you use a hardware serial port? (And handle communication correctly )

6

nodemcu V1. I did not test with the hardware serial. Because I saw that most of them start with a software serial. Can you send me a sample hardware serial code? Thankful

7

In the sim800 module, when a command is sent, it is necessary to make a delay in the program line so that the module is ready for the next command. For example, I tested, if you want to define two numbers for sending SMS, you must delay 5 seconds between the two phone number configurations, otherwise sometimes the SMS will not be sent. Because there is a communication connection, sending and receiving commands is slow and there is a delay.

And for this

if (hour == 19 && minute == 6 && 15>second>0) {

Can you send the correct syntax? thank you

8

There’s only one full UART on the NodeMCU. The second UART is transmit only - you could explore with Serial.swap() if you don’t need debug info but then SoftwareSerial is indeed an option. Just don’t use any delay and read data often.

You can’t check for a value within an interval like you do, you need two tests

if (hour == 19 && minute == 6 && 15 > second && second > 0) {
9

This is completely wrong concept. Instead of just waiting 5 seconds - your program should read the answer from SIM module. If you get "OK" - you can continue further without waiting, but if the modem returns error or nothing - you should send the command again or decide the other way to proceed.

And of course, there should be no delays in the code where you receive something from the modem, such as in updateSerial() function.
Delays are not allowed here, regardless of whether you are accepting responses from the modem or just waiting

10

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