File content as of revision 0:69f8eade26c2:

#include "mbed.h"

// SANS LIBRAIRIE

DigitalOut myled(LED1);
I2C i2c(p9, p10);

Serial pc(USBTX, USBRX); // tx, rx

void initUART(unsigned int baudRate){
    volatile int* const PCONP = (int*) 0x400FC0C4;
    volatile int* const PCLKSEL1 = (int*) 0x400FC1AC;
    volatile int* const U2LCR = (int*) 0x4009800C;
    volatile int* const U2DLL = (int*) 0x40098000;
    volatile int* const U2DLM = (int*) 0x40098004;
    volatile int* const PINSEL0 = (int*) 0x4002C000;
    
    int const clock = 100000000;
    int const clockDiv = 3;
    int const peripheralClock = clock >> clockDiv;
    int const dlmDll = peripheralClock / (baudRate << 4);
    
    *PCONP |= 0x1000000;
    *PCLKSEL1 |= 0x30000;
    *U2LCR |= 0x80;
    *U2DLL = dlmDll & 0xFF;
    *U2DLM = dlmDll & 0xFF00;
    *U2LCR = 0x3;
    *PINSEL0 |= 0x500000;
}

void sendCharToSS(char data){
    volatile int* const U2LSR = (int*) 0x40098014;
    volatile int* const THR = (int*) 0x40098000;
    
    while (*U2LSR & 0x20 == 0) wait_us(25);
    
    *THR = data;
}

int main() {
    initUART(9600);
    int addr = 0x1D << 1;
    
    char cmd[2];
        
    cmd[0] = 0x0D;
    i2c.write(addr, cmd, 1, true);
    i2c.read(addr, cmd, 1);        
        
    pc.printf("Reponse = 0x%02x \r\n",cmd[0]);
    pc.printf((cmd[0] == 0x2a)?"Everything is working fine!":"Oopps, it seems there is an issue...");
    
    cmd[1] = 0x01;
    i2c.write(addr, cmd, 2);
    
    cmd[0] = 0x0F;
    cmd[1] = 0x30;
    i2c.write(addr, cmd, 2);
    
    cac(0x7A);
    cac(0xFF);
    cac(0x76);
    cac(0x77);
    cac(0x02);
        
    int his[20] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
    int length = 20;
    int cpt  = 0;
        
    while(1) {        
        char acc[2];
        cmd[0] = 0x05;
        i2c.write(addr, cmd, 1, true);
        i2c.read(addr, acc, 2);
        
        // Si négatif, propagation du bit de signe
        int z = acc[0] > 127 ? 0xFFFFF000 | (acc[0] << 4) : acc[0] << 4;
        
        // Ajout des LSB
        z += acc[1] >> 4;
        
        z = z > 2047 ? 2048 - z : z;
        z = z > 1024 ? 1024 : z;
        z = z < -1024 ? -1024 : z;
        
        pc.printf("%d \r\n", z);
                
        int angle = acos((double)abs(z)/1024.0) * 5729; //5729 = 180 / pi * 100
        his[cpt] = angle;
        cpt++;
        cpt %= length;
        
        angle = 0;
        for (int i = 0; i < length; i++) angle += his[i];
        
        angle /= length;
                
        pc.printf("Angle : %d\r\n", angle);
        
        sendCharToSS((char)(angle / 1000));
        sendCharToSS((char)((angle / 100) % 10));
        sendCharToSS((char)((angle / 10) % 10));
        sendCharToSS((char)(angle % 10));
        
        pc.printf("--------- \r\n");

        wait(0.025);
    }
}