II'm having issues communicating to the MLX90614, datasheet attached. It seems that I have everything set correctly and the TWI Scanner returns addresses and data. My output messages:
Event Handler was successfully called.
But the Event Handler did not receive a done indication.
TWI device detected at address: 0x0
TWI device rx data: 0x31
Size of:1
Event!! NACK received after sending the address.
Event Handler was successfully called.
TWI device detected at address: 0x1
TWI device rx data: 0x31
It appears things are ok.
However, when I run my normal RAM access to the sensor I get a nack with the below messages:
TWI Init err code: 0
Program initializing!!
Hard Coded Object Temperature: 3700
Running!
Start SMBus Read Memory
Event!! NACK received after sending the address.
Event Handler was successfully called.
But the Event Handler did not receive a done indication.
Tx err_code done: 0
Waiting for tx response...
Below are my key functions, etc which seem to align with what I've been seeing in the forums and documentation for the sensor:
#define TWI_MLX90614_SCL_PIN NRF_GPIO_PIN_MAP(1, 7)
#define TWI_MLX90614_SDA_PIN NRF_GPIO_PIN_MAP(1, 6)
/* TWI instance ID. */
#define TWI_INSTANCE_ID 0
/* TWI instance. */
static const nrf_drv_twi_t twi_mlx90614_instance = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);
/* Indicates if operation on TWI has ended. */
static volatile bool twi_mlx90614_xfer_done = false;
static void twi_mlx90614_init(void)
{
ret_code_t err_code;
nrf_drv_twi_config_t twi_mlx90614_config = NRF_DRV_TWI_DEFAULT_CONFIG;
twi_mlx90614_config.scl = TWI_MLX90614_SCL_PIN,
twi_mlx90614_config.sda = TWI_MLX90614_SDA_PIN,
twi_mlx90614_config.frequency = NRF_TWI_FREQ_100K,
twi_mlx90614_config.interrupt_priority = APP_IRQ_PRIORITY_HIGH,
twi_mlx90614_config.clear_bus_init = false,
err_code = nrf_drv_twi_init(&twi_mlx90614_instance, &twi_mlx90614_config, twi_mlx90614_handler, NULL);
APP_ERROR_CHECK(err_code);
nrf_drv_twi_enable(&twi_mlx90614_instance);
SEGGER_RTT_printf(0,"TWI Init err code: %#u\n", err_code);
}
static void twi_mlx90614_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_TX)
{
SEGGER_RTT_printf(0,"Twi mlx90614 tx evt done.\n");
}
else if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_RX)
{
SEGGER_RTT_printf(0,"Twi mlx90614 rx evt done.\n");
}
else if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_TXRX)
{
printf("Twi mlx90614 txrx evt done.");
SEGGER_RTT_printf(0,"Twi mlx90614 txrx evt done.\n");
}
else if (p_event->xfer_desc.type == NRF_DRV_TWI_XFER_TXTX)
{
SEGGER_RTT_printf(0,"Twi mlx90614 txtx evt done.\n");
}
twi_mlx90614_xfer_done = true;
} break;
case NRF_DRV_TWI_EVT_ADDRESS_NACK:
SEGGER_RTT_printf(0,"Event!! NACK received after sending the address.\n");
break;
case NRF_DRV_TWI_EVT_DATA_NACK:
SEGGER_RTT_printf(0,"Event!! NACK received after sending a data byte.\n");
break;
default:
break;
}
SEGGER_RTT_printf(0,"Event Handler was successfully called.\n");
if(twi_mlx90614_xfer_done == false){
SEGGER_RTT_printf(0,"But the Event Handler did not receive a done indication.\n");
}else{
SEGGER_RTT_printf(0,"Event Handler received done indication!!!\n");
}
}
uint16_t Read_MLX_Memory(uint8_t slave_Address, uint8_t command)
{
ret_code_t err_code;
uint16_t data; // Data storage (DataH:DataL)
uint8_t Pec; // PEC byte storage
uint8_t PecReg; // Calculated PEC byte storage
uint8_t arr[6]; // Buffer for the sent bytes
uint8_t DataL = 0; // Low data byte storage
uint8_t DataH = 0; // High data byte storage
uint8_t rx_data[3] = {0}; // Data received from twi
uint8_t tx_data = {command}; // Data sent from twi .
slave_Address <<= 1; // 2-7 bits indicate the slave address
do
{
SEGGER_RTT_printf(0,"Start SMBus Read Memory\n");
err_code = nrf_drv_twi_tx(&twi_mlx90614_instance, slave_Address, &tx_data, sizeof(tx_data), true);
nrf_delay_ms(10);
SEGGER_RTT_printf(0,"Tx err_code done:0x%#u\n", err_code);
// APP_ERROR_CHECK(err_code);
twi_mlx90614_xfer_done = false;
SEGGER_RTT_printf(0,"Waiting for tx response...\n");
// while (twi_mlx90614_xfer_done == false);
do
{
__WFE();
} while(twi_mlx90614_xfer_done == false);
SEGGER_RTT_printf(0,"Transmit done, start receive\n");
err_code = nrf_drv_twi_rx(&twi_mlx90614_instance, slave_Address, rx_data, 3);
// APP_ERROR_CHECK(err_code);
twi_mlx90614_xfer_done = false;
do
{
__WFE();
} while(twi_mlx90614_xfer_done == false);
SEGGER_RTT_printf(0,"Receive data done\n");
DataL = rx_data[0];
DataH = rx_data[1];
Pec = rx_data[2];
arr[5] = slave_Address;
arr[4] = command;
arr[3] = slave_Address + 1;
arr[2] = DataL;
arr[1] = DataH;
arr[0] = 0;
PecReg = PEC_Calculation(arr); // Calculate CRC
} while(PecReg != Pec); // If received and calculated CRC are equal get out of do-while{}
data = (DataH << 8) | DataL; // data = DataH:DataL
SEGGER_RTT_printf(0,"Read Memory done and return data\n");
return data;
}
//This function is called from main:
static float Read_MLX_Object_Temp(void)
{
return Read_MLX_Memory(MLX90614_ADDRESS, (OBJ1_TEMP));
}
Please let me know if you see something incorrect. The project is currently at a stand still. IO
