CC2642R: Display_printf vs UART_write

Gokul Krishna Krishnakumar

Part Number: CC2642R

I want to log data from the board to my linux machine, when i use Display_printf (initalized with Display_Type_UART) to transmit serial data I can see all the data correctly on my linux machine with minicom.

But when I use UART_write to transmit serial data from the board I am seeing random gibberish getting printed on the machine.

1. What is the different between Display_printf and UART_write?

2. When I use Display_printf, it takes almost 3ms to transmit 1 byte of data, why is this so- can i reduce this value?

over 6 years ago

0 TER over 6 years ago

TI__Guru**** 317180 points

1) If you look at the driver (C:\ti\<SDK path>\source\ti\display), the display driver uses UART_write. Have you checked that the baudrate is set correctly? If you get gibberish this is typically the issue.

2) 1 byte as one letter (char)? The default baud rate is 115200 meaning that a char should be printed out in the scale of us and not ms.

0 Gokul Krishna Krishnakumar over 6 years ago in reply to TER

Intellectual 260 points

Yes the Baudrate is set correctly- its at 115200

It should be in microseconds but each time i call a Display_printf it takes around 3ms- no matter what the size of array that i give to print, be it 1 char or 5 chars.

0 TER over 6 years ago in reply to Gokul Krishna Krishnakumar

TI__Guru**** 317180 points

How do you measure the time it takes to print? I find it a bit strange that the time is independent on the length of what you want to print.

0 Gokul Krishna Krishnakumar over 6 years ago in reply to TER

Intellectual 260 points

static void Print_thread()

{

static uint32_t time1, time2,dt;

dispHandle = Display_open(Display_Type_UART, NULL);

for (;;)
{

time2 = Clock_getTicks();
dt = time2 - time1;
Display_printf(dispHandle, MR_ROW_CUR_CONN+line_no, 0, "%d\n\r",dt);// this always gives an output of 3xx, which is 3ms
line_no++;
time1 = Clock_getTicks();

}