DFRobot SIM7000 library not compiling - Wnarrowing error

Question

I am working with an Arduino Mega and a SIM7000E Arduino NB-IoT/LTE/GPRS/GPS Expansion Shield. I tried to run the example provided by DFRobot in their tuto but a narrowing error appears in the lib. On the web they propose me to change code to avoid this problem but since it is a library I should not mess with it. Has anybody an idea ?

I am working on VSCode with the platformIO integrated IDE. My compiler is gcc and I have downloaded the two used library from DFRobot_SIM7000 and DFRobot_SIM

Example code:

`#include <Wire.h>
#include <DFRobot_SIM7000.h>

#define PIN_TX     7
#define PIN_RX     8
SoftwareSerial     mySerial(PIN_RX,PIN_TX);
DFRobot_SIM7000    sim7000;
static char        buff[350];

void setup(){
    int signalStrength,dataNum;
    Serial.begin(115200);
    sim7000.begin(mySerial);
    sim7000.turnOFF();
    delay(5000);
    Serial.println("Turn ON SIM7000......");
    if(sim7000.turnON()){                                                                      //Turn ON SIM7000
        Serial.println("Turn ON !");
    }
    Serial.println("Set baud rate......");
    if(sim7000.setBaudRate(19200)){                                                            //Set baud rate from 115200 to 19200
        Serial.println("Set baud rate:19200");
    }else{
        Serial.println("Faile to set baud rate");
        while(1);
    }
    Serial.println("Check SIM card......");
    if(sim7000.checkSIMStatus()){                                                              //Check SIM card
        Serial.println("SIM card READY");
    }else{
        Serial.println("SIM card ERROR");
        while(1);
    }
    delay(500);
    Serial.println("Set net mod......");
    if(sim7000.setNetMode(NB)){                                                                    //Set net mod NB-IOT
        Serial.println("Set NB-IOT mode");
    }else{
        Serial.println("Fail to set mode");
    }
    Serial.println("Get signal quality......");
    delay(500);
    signalStrength=sim7000.checkSignalQuality();                                               //Check signal quality from (0-30)
    Serial.print("signalStrength =");
    Serial.println(signalStrength);
    delay(500);
    Serial.println("Attaching service......");
    if(sim7000.attacthService()){                                                              //Open the connection
        Serial.println("Attach service");
    }else{
        Serial.println("Fail to Attach service");
        while(1);
    }
    delay(200);
    Serial.println("Connecting......");
    if(sim7000.openNetwork(TCP,"www.taobao.com",80)){                                              //Start Up TCP or UDP Connection
        Serial.println("Connect OK");
    }else{
        Serial.println("Fail to connect");
        while(1);
    }
    sim7000.send("HEAD/HTTP/1.1\r\nHost:www.taobao.com\r\nConnection:keep-alive\r\n\r\n");     //Send Data Through TCP or UDP Connection
    dataNum=sim7000.recv(buff,350,0);                                                          //Receive data
    Serial.print("dataNum=");
    Serial.println(dataNum);
    Serial.println(buff);
    delay(500);
    if(sim7000.closeNetwork()){                                                   //End the connection
        Serial.println("Close connection");
    }else{
        Serial.println("Fail to close connection");
    }
    delay(2000);
    sim7000.turnOFF();                                                                         //Turn OFF SIM7000
}

void loop() {
    delay(1000);
}`

Error output:

lib\DFRobot_SIM7000\DFRobot_SIM7000.cpp: In member function 'bool DFRobot_SIM7000::mqttConnect(char*, char*, char*)':
lib\DFRobot_SIM7000\DFRobot_SIM7000.cpp:312:77: error: narrowing conversion of '194' from 'int' to 'char' inside { } [-Wnarrowing]
     char MQTThead[10]={0x00,0x04,0x4d,0x51,0x54,0x54,0x04,0xc2,0x0b,0xb8};
                                                                         
lib\DFRobot_SIM7000\DFRobot_SIM7000.cpp:312:77: error: narrowing conversion of '184' from 'int' to 'char' inside { } [-Wnarrowing]
lib\DFRobot_SIM7000\DFRobot_SIM7000.cpp: In member function 'bool DFRobot_SIM7000::mqttDisconnect()':
lib\DFRobot_SIM7000\DFRobot_SIM7000.cpp:427:40: error: narrowing conversion of '224' from 'int' to 'char' inside { } [-Wnarrowing]

You should post the errors here as text, not images. Given that, you need to take a look closely at that last warning, where it states you've reached the end of a non-void function without returning. Regardless of any of the other errors, if you get your program to compile and run, you will be invoking undefined behavior for that function if it reaches the end without returning a value. Thus that library may be buggy. — PaulMcKenzie, Jun 01 '21 at 07:54

score 0 · Answer 1 · answered May 12 '22 at 21:32

0

Open DFRobot_SIM7000.h file and change String.h to string.h. You should have string.h already available and your code should compile.

answered May 12 '22 at 21:32

Szymon

1

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community May 13 '22 at 09:15

DFRobot SIM7000 library not compiling - Wnarrowing error

1 Answers1