regarding uart with 4800 baud rate

[manikandan]

hello i am trying to interface RN8209c ic with nrf52832 using uart communication with sdk 15.2 

uint8_t readbuf[50];

uint32_t err_code;sdk_config.txt

uint8_t buf[10];
buf[0]=0x7f;
uint8_t buf_len=0;
uint8_t buf_r[10];
nrf_drv_uart_config_t cfg = NRF_DRV_UART_DEFAULT_CONFIG;

cfg.baudrate = UART_BAUDRATE_BAUDRATE_Baud4800;
cfg.hwfc = NRF_UART_HWFC_DISABLED;
cfg.pselrxd = 13;
cfg.pseltxd = 14;
cfg.use_easy_dma = false;
cfg.parity = true;
ret_code_t ret;
nrf_drv_uart_init(&app_uart_inst, &cfg, NULL);
nrf_drv_uart_rx_enable(&app_uart_inst);
err_code=nrf_drv_uart_rx(&app_uart_inst, readbuf, 50);

if (err_code != NRF_SUCCESS)
{
NRF_LOG_ERROR("Failed initializing rx\n");
printf("Failed initializing rx\n");
}
nrf_drv_uart_tx(&app_uart_inst,(uint8_t*) buf, 1);
nrf_drv_uart_rx(&app_uart_inst, (uint8_t*)buf_r, 4);

printf("%x\n",buf_r[0]);
printf("%x\n",buf_r[1]);
printf("%x\n",buf_r[2]);
printf("%x\n",buf_r[3]);

my code got stuck in first nrf_drv_uart_rx line and i have attached my sdk_config file and i have checked my tx rx pins that is working fine

can someone tell me?

thanks and regards

manikandan v

[Susheel Nuguru]

So your device is not receiving 4 bytes as expected. Are you sure that the peer serial device has transmitted the 4 bytes you are waiting for here? Do you have any logic analyzer or any other probe to sniff the TX and RX pins and can you please show that pin trace snapshot here?

[manikandan]

yes,but when i use app_uart_put  to send my tx value i can get the excepted value of rx but only one byte i want to get all my rx values using this nrf_drv_uart_rx(&app_uart_inst, (uint8_t*)buf_r, 4);  my sensor will give maxium values of 4 bytes at a time

[Susheel Nuguru]

It is still unclear to me if your sensor is transmitting this 4 bytes and the nRF UART is not receiving them? 

If your sensor is still transmitting only 1 byte (similar to your use case of app_uart_put, then nrf_drv_uart_rx will not change that. And you will not get an event from uart unless you get those 4 bytes from the receiver. I would still like to see that the issue you are seeing is in fact in the Nordic side and not at the peer side. This I can only be sure if I can see that your peer is transmitting 4 bytes but nRF is not able to receive them. Can you please check if you can attach some pin sniffing logs so that I can see what the peer sent?