File content as of revision 0:e062501cfe81:

#include "Accelerometer.h"


#define REG_CTRL_REG_1    0x2A 
#define REG_OUT_X_MSB     0x01
#define REG_OUT_Y_MSB     0x03
#define REG_OUT_Z_MSB     0x05

Accelerometer::Accelerometer(PinName sda, PinName scl, int address) : i2c(sda, scl), addr(address) {
    // activate the peripheral
    uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
    writeRegs(data, 2);
}

Accelerometer::~Accelerometer() { }


float Accelerometer::Acc_X() {
//divide by 4096 b/c MMA output is 4096 counts per g so this f outputs accelorometer value formatted to g (gravity)
    return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
}

float Accelerometer::Acc_Y() {
    return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
}

float Accelerometer::Acc_Z() {
    return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
}



int16_t Accelerometer::getAccAxis(uint8_t addr) {
    int16_t acc;
    uint8_t result[2];
    readRegs(addr, result, 2);

    acc = (result[0] << 6) | (result[1] >> 2);
    if (acc > 16383/2)
        acc -= 16383;

    return acc;
}

void Accelerometer::readRegs(int addr, uint8_t * data, int len) {
    char t[1] = {addr};
    i2c.write(addr, t, 1, true);
    i2c.read(addr, (char *)data, len);
}



void Accelerometer::writeRegs(uint8_t * data, int len) {
    i2c.write(addr, (char *)data, len);
}