nrf52832 + LIS2DH12 : Issue using I2C : no address acknowledge (NACK) received

Question

Hi ! 
 
 I'm using the nrf52832 chip and I'm trying to communicate with a LIS2DH12 accelerometer using the I2C protocol. 
 But unfortunately I can't handle with it, it seems that the accelerometer doesn't respond at his adress... 
 
 So first here is my hardware connections : 
 
 The pin are connected as follow to the nrf52832 : 
 SDA - P0.14 
 SCL - P0.15 
 
 As said in the LIS2DH12 datasheet, the SD0 pin is connected to the supply voltage so the I2C address of the accelerometer is 0x19. 
 
 Here are the relevant firmware parts : 
 1) Address of the LIS2DH12 
 /* TWI instance ID. */
#define TWI_INSTANCE_ID 0
/* Common addresses definition for temperature sensor. */
#define C_ACCELEROMETER_I2C_ADDR 0x19 
 2) twi_handler() and twi_init() 
 /**
 * @brief TWI events handler.
 */
void twi_handler(nrf_drv_twi_evt_t const * p_event, void * p_context)
{
 switch (p_event->type)
 {
 case NRF_DRV_TWI_EVT_DONE:
 if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
 {
 data_handler(m_sample);
 }
 m_xfer_done = true;
 break;
 
 case NRF_DRV_TWI_EVT_ADDRESS_NACK:
 break;
 
 case NRF_DRV_TWI_EVT_DATA_NACK:
 break;
 
 default:
 break;
 }
}

/**
 * @brief TWI initialization.
 */
void twi_init (void)
{
 ret_code_t err_code;

 const nrf_drv_twi_config_t twi_lm75b_config = {
 .scl = 15, 
 .sda = 14,
 .frequency = NRF_TWI_FREQ_100K,
 .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
 .clear_bus_init = false
 };

 err_code = nrf_drv_twi_init(&m_twi, &twi_lm75b_config, twi_handler, NULL);
 APP_ERROR_CHECK(err_code);

 nrf_drv_twi_enable(&m_twi);
} 
 
 So as you can see, I've just followed the nordic example (twi_sensor). 
 But when I try to configure the accelerometer with this function : 
 /**
 * @brief Function for LIS2DH accelerometer config.
 */
void fn_configure_LIS2DH_accelero(void)
{
 ret_code_t err_code;

 //lire who i am
 
 m_xfer_done = false; 
 uint8_t reg2[2] = {C_WHO_AM_I, 0x00}; 
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg2, 1, true);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 /* Read 1 byte from the specified address - skip 3 bits dedicated for fractional part of temperature. */ 
 err_code = nrf_drv_twi_rx(&m_twi, C_ACCELEROMETER_I2C_ADDR, m_sample_axis, 1); 
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 
 /* Writing . */
 m_xfer_done = false;
 reg[0] = C_CTRL_REG1;
 reg[1] = 0x37; //Oliver : X,Y,Z axis enabled ; Sampling Rate = 25Hz
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, true);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_CTRL_REG2;
 reg[1] = 0x09; //High-pass filter enabled on interupt activity 1
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_CTRL_REG3;
 reg[1] = 0x40; //IA1 Interupt on pin INT1
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_CTRL_REG4;
 reg[1] = 0x10; //Olivier : full scale +/- 4g
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_CTRL_REG5;
 reg[1] = 0x08; //Interupt 1 pin latched
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_INT1_THS;
 reg[1] = 0x08; //INT1 threshold to 8 * 32mg = 256mg (32mg per LSB at Full Scale = +/-4g
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 reg[0] = C_INT1_DURATION;
 reg[1] = 0x02; //INT1 duration = 2/ODR so at 25Hz, duration = 80ms
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);

 //dummy read of reference to force the HP to the current accelerometer value
 m_xfer_done = false;
 reg[0] = C_REFERENCE; 
 reg[1] = 0x00;
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 1, true);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
 m_xfer_done = false;
 err_code = nrf_drv_twi_rx(&m_twi, C_ACCELEROMETER_I2C_ADDR, &m_reference, 1); 
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 //end of read
 
 m_xfer_done = false;
 reg[0] = C_INT1_CFG;
 reg[1] = 0x02; // Enable XH interrupt generation
 err_code = nrf_drv_twi_tx(&m_twi, C_ACCELEROMETER_I2C_ADDR, reg, 2, false);
 APP_ERROR_CHECK(err_code);
 while (m_xfer_done == false);
 
} 
 
 The program get stuck in the first while loop : 
 while (m_xfer_done == false); 
 
 And using a breakpoint, I can see that the twi_handler() is called because an NRF_DRV_TWI_EVT_ADDRESS_NACK event is rised. 
 
 So it seems that the lis2dh12 does not respond... 
 
 I tried to "scan" every adresses from 1 to 126 and for each I receive the same event : NRF_DRV_TWI_EVT_ADDRESS_NACK

Is there a configuration that I forgot ? Maybe the SDA and SCL pins needs to an internal pull-up ? 
 I don't understand, so if someone could help me, it would be great ! 
 
 Thank you !! 
 Olivier