app_uart_init() function error:

Question

Hello, 
 I wanted to add uart in ble_custom_template project. I have added UART and FIFO Libraries in User include Libraries. Also i set the bits for uart in sdk_config.h. Still I get following error. 
 Linking xyz.elf Output/Release/Obj/smart_cap_v1/modbus_handle.o: in function `uart_init': undefined reference to `app_uart_init' Build failed 
 I read other Q and A also as lot of people have this error. But didnt get promisable answer. Please guide me for the same. 
 
 Thank you in advance. 
 Regards.

chinmaydixit · Answer

Hello, I solved the problem by adding some macro definations from uart example to my project which are not in my project. It solved my error. But right now, I have a problem with app_uart_get function though I can see the data on RX pin. Also it seems NRF_DRV_UART_EVT_RX_DONE is generated. void data_send_uart(uint8_t slaveaddress,uint8_t fn_code,uint16_t start_address,uint16_t number_of_pts) { char crc_data[2]={0}; uint8_t data_write[8]; uint8_t len,Index=0; unsigned char CRCLo = 0xff; unsigned char CRCHi = 0xff; unsigned char *puchMsg; uint16_t crc; data_write[0]=slaveaddress; data_write[1]=fn_code; data_write[2]=start_address/256; data_write[3]=start_address%256; data_write[4]=number_of_pts/256; data_write[5]=number_of_pts%256; len=sizeof(data_write)-2; puchMsg= data_write; while(len--) { Index = CRCLo ^ *puchMsg; puchMsg++; CRCLo = CRCHi ^ auchCRCHi[Index]; CRCHi = auchCRCLo[Index]; } data_write[6]=CRCLo; data_write[7]=CRCHi; printf("CRC Low Byte : %x ",data_write[6]); printf("CRC High Byte : %x ",data_write[7]); printf("data sent : "); for(int i=0;ievt.gatts_evt.params.authorize_request; data_send_uart(21,4,0,1); nrf_delay_ms(500); //while(uart_received_flag==0); uart_received_flag=0; //err_code=app_uart_get(rx_data[0]); for(int i=0;i<8;i++) { err_code=app_uart_get(&rx_data[i]); printf("error code %d",err_code); APP_ERROR_CHECK(err_code); } printf("Rx data :%s",rx_data); if(req.type == BLE_GATTS_AUTHORIZE_TYPE_READ){ ble_gatts_rw_authorize_reply_params_t response; response.params.read.gatt_status = BLE_GATT_STATUS_SUCCESS; response.type = BLE_GATTS_AUTHORIZE_TYPE_READ; response.params.read.update = 1; response.params.read.offset = 0; response.params.read.len =strlen(data); response.params.read.p_data = (uint8_t *)data; err_code=sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.gatts_evt.conn_handle, &response); APP_ERROR_CHECK(err_code); //NRF_LOG_INFO("Reply function responded with: %d", err_code); } } This is my OnRead Function when there is a read Command and on which we respond to that command sd_ble_gatts_rw_authorize_reply function. In this function I am sending some MODBUS Data to my controller (right now i am just shorting TX and RX for testing) and trying to get the data which will be present in RX_FIFO and for that, i am using app_uart_get. But everytime I get ERROR CODE 5 which is NRF_ERROR_NOT_FOUND. Please guide me. Thank you so much. Regards.