shield for Arduino Sparkfun DEV-11848

I bought a shield for Arduino Sparkfun DEV-11848 https://www.sparkfun.com/products/11848

I modified an exemplary and I could get the display of a program number. In my case 3542 :

Wire.endTransmission(); i2cSendString("3542"); //Send the four characters to the display

Here is my problem: I would like to display a variable instead of "3542" This variable has the following format :

volatile int compt=0; // variable de comptage volatile

How to display the value of the variable compt instead of 3542 ?

Thank you for your help

How to display the value of the variable compt instead of 3542 ?

Since you need to define what to display as a a string, you need to convert the value to a string. The itoa() function does just that.

Thank you for the reply.

I have other question s:

Should we add a library to the Arduino software ?

I tried to use the itoa instruction without adding library but I have an error message. Maybe I do not have the correct syntax ?

Thank you

Maybe I do not have the correct syntax ?

My crystal ball says you don't.

Ahhhh ça fonctionne
Le programme :

/*

Broches Arduino utilisées
A5 to SCL
A4 to SDA
VIN to PWR
GND to GND

*/

int compt0 = 6931; //déclaration du nombre 6931

#include <Wire.h>

#define DISPLAY_ADDRESS1 0x71 //C’est l’adresse par défaut de la OpenSegment avec les deux jumpers ouverts

void setup()
{
Wire.begin(); // Connection au bus I2C en tant que maitre

Wire.beginTransmission(DISPLAY_ADDRESS1); // Débute une transmission sur le bus I2C vers le composant esclave ayant l’adresse indiquée
Wire.write(‘v’); // envoie la valeur
Wire.endTransmission(); // finalise la transmission
}

void loop()
{
Wire.beginTransmission(DISPLAY_ADDRESS1);
Wire.write(0x7A); // Brightness control command
Wire.write(50); // Set brightness level: 0% to 100%
Wire.endTransmission();

char buffer[4]; // buffer de 4 caractères (Mais ça fonctionne avec 0 et aussi avec un nombre qui a plus de 4 caractères ???)

itoa(compt0,buffer,10); // conversion de compt0 en 4 caractères décimaux

i2cSendString(buffer); //Send the four characters to the display

delay(1000);

}

void i2cSendString(char *toSend) // Envoie les 4 premiers caractères
{
Wire.beginTransmission(DISPLAY_ADDRESS1); // transmit to device #1
for(byte x = 0 ; x < 4 ; x++)
Wire.write(toSend); //Send a character from the array out over I2C
Wire.endTransmission(); //Stop I2C transmission
}

I'm not sure how you expect '6', '9', '3', '1', and NULL to fit in a 4 element array. I'm not sure what error message you are seeing. I AM sure that your code doesn't really look like that. I AM sure that you didn't read the "How to post on this forum" sticky at the top of the forum.