ADXL345 with ESP8266 using ThingSpeak error problem

Projects General Guidance
1

Hello,
I am trying run the adxl345 with esp8266 using thingspeak cloud. but i got error that "Error compiling for board Arduino Uno" & " ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]".

please help !

Here is the code

#include <SoftwareSerial.h>
#include <Wire.h>
//#include <Wire.h>
#define RX 2
#define TX 3
int getSensorData();
int ADXL345 = 0x53;
int X_out, Y_out, Z_out;
int countTrueCommand;
int countTimeCommand; 
boolean found = false; 
int valSensor = 1;
int sendCommand();
String AP = "High Voltage Lab";       // AP NAME
String PASS = "profnkroy"; // AP PASSWORD
String API = "ERK34DSVQ9XJGLO2";   // Write API KEY
String HOST = "api.thingspeak.com";
String PORT = "80";
String field1 = "field1";
String field2 = "field2";
String field3 ="field3";
//int X_OUT,Y_OUT,Z_OUT;
SoftwareSerial esp8266(RX,TX); 
 
  
void setup() {
  Serial.begin(9600);
  esp8266.begin(115200);
  Wire.begin();
  sendCommand("AT",5,"OK");
  sendCommand("AT+CWMODE=1",5,"OK");
  sendCommand("AT+CWJAP=\""+ AP +"\",\""+ PASS +"\"",20,"OK");
  Serial.begin(9600);
  Serial.println("date&time,x_out,y_out,z_out");
  Wire.beginTransmission(ADXL345);
  Wire.write(0x2D); //talk to POWER_CTL Register - 0x2D
  Wire.write(8); // Bit D3 High for measuring enable (8dec -> 0000 1000 binary)
  Wire.endTransmission();
  delay(10);
}

void loop()  {
valSensor = getSensorData();
String getData = "GET /update?api_key="+ API +"&field1="+valSensor+"&field2="+valSensor+"&field3="+valSensor;// field +"="+String(valSensor);//CHANGE
sendCommand("AT+CIPMUX=1",5,"OK");
sendCommand("AT+CIPSTART=0,\"TCP\",\""+ HOST +"\","+ PORT,15,"OK");
sendCommand("AT+CIPSEND=0," +String(getData.length()+4),4,">");
esp8266.println(getData);delay(1500);countTrueCommand++;
sendCommand("AT+CIPCLOSE=0",5,"OK");
Wire.beginTransmission(ADXL345);
Wire.write(0x32);
Wire.endTransmission(false);
Wire.requestFrom(ADXL345, 6, true);

  X_out = ( Wire.read() | Wire.read() << 8);
  Y_out = ( Wire.read() | Wire.read() << 8);
  Z_out = ( Wire.read() | Wire.read() << 8);
  

  Serial.print(",");
  Serial.print(X_out);
  Serial.print(",");
  Serial.print(Y_out);
  Serial.print(",");
  Serial.println(Z_out);
  delay(0.00000001);
}
 // return random(1000); // Replace with your own sensor code
 

void sendCommand(String command, int maxTime, char readReplay[]) {
  Serial.print(countTrueCommand);
  Serial.print(". at command => ");
  Serial.print(command);
  Serial.print(" ");
  while(countTimeCommand < (maxTime*1))
  {
    esp8266.println(command);//at+cipsend
    if(esp8266.find(readReplay))//ok
    {
      found = true;
      break;
    }
  
    countTimeCommand++;
  }
  
  if(found == true)
  {
    Serial.println("OYI");
    countTrueCommand++;
    countTimeCommand = 0;
  }
  
  if(found == false)
  {
    Serial.println("Fail");
    countTrueCommand = 0;
    countTimeCommand = 0;
  }
  
  found = false;
 }

here is error message:

C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino: In function 'void setup()':
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:30:26: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   sendCommand("AT",5,"OK");
                          ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:31:35: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   sendCommand("AT+CWMODE=1",5,"OK");
                                   ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:32:61: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
   sendCommand("AT+CWJAP=\""+ AP +"\",\""+ PASS +"\"",20,"OK");
                                                             ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino: In function 'void loop()':
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:45:33: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
 sendCommand("AT+CIPMUX=1",5,"OK");
                                 ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:46:66: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
 sendCommand("AT+CIPSTART=0,\"TCP\",\""+ HOST +"\","+ PORT,15,"OK");
                                                                  ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:47:62: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
 sendCommand("AT+CIPSEND=0," +String(getData.length()+4),4,">");
                                                              ^
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL\Revised_ESP_ADXL.ino:49:35: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]
 sendCommand("AT+CIPCLOSE=0",5,"OK");
                                   ^
C:\Users\DELL\AppData\Local\Temp\ccGq0fs3.ltrans0.ltrans.o: In function `loop':
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL/Revised_ESP_ADXL.ino:43: undefined reference to `getSensorData()'
collect2.exe: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino Uno.
2 
C:\Users\DELL\Documents\program@ard\Revised_ESP_ADXL/Revised_ESP_ADXL.ino:43: undefined reference to `getSensorData()

You do not have a definition for the getSensorData() function in your sketch

3

I am new to arduino programming . please help what should modified or added to my sketch .
thank you!

4

Your sketch needs a getSensorData() function to be defined

There is a very odd comment in the sketch

// return random(1000); // Replace with your own sensor code

Where did you get the sketch ?

5

from one of the site in google . i got basic structure of sketch them i modified it . and i got lot of error ,many error i resolved . but i stuck in this error from past 2 days.

6

Did the original sketch have the function in it ?

7

yes .
basically i merge two individual program adxl345 and esp8266 . both program run individually . but when merged both then error occurred .
if possible ,please help

8

Copy the function from the original to your sketch but I have no great hope that the combined sketch will work as you want even if it compiles

9

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