Send command over UART

Question

I have a laser distance sensor module. I want to connect this module with my nRF52 DK(PCA10040). The module communicates over UART: 
 
 
 Supply (2.8V-3.2V VDC) connected to VDD on the nRF52DK 
 
 
 Ground connected to GND on the nRF52DK 
 
 
 Tx connected to P0.06(Tx on DK) 
 
 
 Rx connected to P0.08(Rx on DK) 
 
 
 Communication from module: 
 
 UART: 19200, 8N1 
 Send command of "O":turn on the laser 
 Send command of "C":turn off the laser 
 Send command of "D":measure distance and return results 
 Send command of "S":return module supply voltage 
 
 Here my Uart init: 
 static void uart_init(void)
{
 uint32_t err_code;
 const app_uart_comm_params_t comm_params =
 {
 RX_PIN_NUMBER,
 TX_PIN_NUMBER,
 RTS_PIN_NUMBER,
 CTS_PIN_NUMBER,
 APP_UART_FLOW_CONTROL_ENABLED,
 false,
 UART_BAUDRATE_BAUDRATE_Baud19200 
 };

 APP_UART_FIFO_INIT( &comm_params,
 UART_RX_BUF_SIZE,
 UART_TX_BUF_SIZE,
 uart_event_handle,
 APP_IRQ_PRIORITY_LOW,
 err_code);
 APP_ERROR_CHECK(err_code);
}
 
 If I have understood the example for Uart correctly, printf is for sending and uart_event_handle is the function for recieving. 
 Now if I do this: 
 printf("
C
"); 
 On the Putty I will get a "C". 
 But when I measure the Tx(from nRF52DK to module) signals on the logic analyzer, I wont get 0x43(ASCII code for "C"). 
 
 There will be 5 Bytes: 
 
 
 0xB0 
 
 
 0x50 
 
 
 0x92 
 
 
 0xB0 
 
 
 0x50 
 
 
 Why are there 5 Bytes? And why is there no 0x43?

Jorge · Accepted Answer

I'm not sure how you getting the 5 bytes. You are getting 5 Bytes because you are sending 5 chars:
2 times "
", 2 times "" and one "C". 
 And you are getting the "C" on the middle one. You receive the LSB first, so from your image you get on the 3 Byte "11000010" that you need to reverse the order to "01000011" which is 0x43 and "C". 
 The others values are 0x0D for the carriage return and 0x0A for the line feed.