Uart_echo problem

Please could you let me know:

1. Which board are you running this application on?

2. Have you successfully run the uart_echo example binaries that are included in the TivaWare release for the board?

Looking at your code, the only obvious problem I see is that the UARTSend function will throw data away if you try to send more data than can fit in the UART FIFO. Assuming you only send a short string, though, this will be fine.

Hi Dave ,

thanks for your quick response..... 

1. I am using TM4c123GXL bord(tm4c123gh6pm on chip),

2. yes, the give uart echo example was complied and load successfully but no data on hyper terminal.

and please rectify my problem.

The TIvaWare package for your board includes binaries for each example application. We have tested these and know that they work. Please could you run one of these (flash it to the board using the LM Flash Programmer tool. You will find the binaries in directories named after each toolchain under examples/boards/ek-tm4c123gxl/uart_echo.) and make sure that it works.

If it works, then we are looking for something that you have changed in the example source or in the toolchain setup that is causing the problem. If it doesn't work then either your board has a problem or there is something wrong in the configuration of your PC, either in Hyperterminal or with the device drivers for the board.

A couple of other things to check:

1. Make sure you are connecting your board to the PC using the Debug USB connector and not the Device USB connector. UART0 is supported via the debug connection.

2. Does Hyperterminal work with other serial devices attached to your PC?

3. Make sure your Hyperterminal serial port is configured to operate at 115,200bps, 8 bit data, 1 stop bit, no parity.

If all these things are fine then you will need to use the debugger to determine whether data is being received by the uart_echo application when you type on the PC. Put a breakpoint in the UART interrupt handler (UARTIntHandler) and, if the debugger stops there, step through it to see what is happening. If the debugger doesn't stop there when you type on Hyperterminal then no data is arriving from the PC and you may need to use a logic analyzer or oscilloscope to look at the UART0RX line to see if there is any signal there.

Hi Dave,

Thanks for your information..I overcome that problem with your reference . Now I am getting a problem to read the Uart data . i.e. I simply send one string to UART1 and then I read that string in WHILE loop. here my problem is ..I was send data with out any  problem but at reading time no data is available. please go through code and suggest me. Thanking you.

#include <stdbool.h>
#include <stdint.h>

#include "inc/hw_ints.h"
#include "inc/hw_gpio.h"
#include "inc/hw_memmap.h"
#include "inc/hw_sysctl.h"
#include "inc/hw_types.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/interrupt.h"
#include "driverlib/timer.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"

void init_uart(){
SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART1);


//UARTEnable(SYSCTL_PERIPH_UART1);
GPIOPinConfigure(GPIO_PB0_U1RX);
GPIOPinConfigure(GPIO_PB1_U1TX);
GPIOPinTypeUART(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1);
UARTConfigSetExpClk(UART1_BASE, SysCtlClockGet(), 9600,UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART7);
// Set up I/O pins for chosen port
GPIOPinTypeUART(GPIO_PORTE_BASE, GPIO_PIN_0 | GPIO_PIN_1);
UARTConfigSetExpClk(UART7_BASE, SysCtlClockGet(), 9600,UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE);
//UARTFIFOLevelSet(UART7_BASE, UART_FIFO_TX1_8, UART_FIFO_RX1_8);







}

}

int main(void){

init_uart();

int i= 0;
char name[20] = "hi world\n\r";
while(name[i] != '\0'){
SysCtlDelay(100000);
UARTCharPutNonBlocking(UART1_BASE,name[i]);
i++;
SysCtlDelay(100000);
}


while (1) {

while(UARTCharsAvail(UART1_BASE)){

UARTCharPutNonBlocking(UART1_BASE, UARTCharGetNonBlocking(UART1_BASE));
SysCtlDelay(10000000);
}

}

Please let me ask one of my original questions again. Have you successfully run one of the pre-compiled versions of uart_echo that is included in TivaWare? I am asking about the uart_echo.bin files that we provide, not a version that you have rebuilt yourself. If this works, we can be sure that your PC Hyperterminal is set up correctly and that the virtual COM port is working.

Looking at your code, I have a few questions:

1. Why are you configuring both UART1 and UART7?

2. The main part of the code uses UART1. This is not connected to the USB virtual COM port so you must be using an external circuit to connect this to your PC somehow. Are you sure this circuit is correct and that the voltage levels you are using are correct for whatever serial port connection you are using?

3. Your initial UARTCharPutNonBlocking() loop will only work if the string you are sending contains less characters than the transmit FIFO depth. To make it work regardless of the string length, use UARTCharPut() instead. This function will wait for space in the FIFO before writing a character.

HI Dave,

1.  I am working on Keil UV4 compiler . I was download the file directly into the launch pad and i am not using LM flash player hear.  in this case virtual COM port was not working. please guide me in this problem.

and coming to our questions.

1.  firstly I planed that send data on UART7 th port and then read that data on UART1 . for that i am using 7th port.

2. yes, i designed external MAX232 circuit  to read the uart1 data .

I'm a but confused over exactly what you are now trying to do but, looking at the last code you post, I don't see any calls to GPIOPinConfigure for the UART7 pins you intend using. Make sure you add these and see if that helps.

If you are using UART1 and UART7, the virtual COM port our virtual COM port driver will not be involved. Only COM0 is wired to the debug interface which supports the PC virtual COM port. If you are using some other UART, you will either have to modify your LauchPad to connect that UART to the debug interface (and break the connections to UART0) or use some other serial port on your PC (or a USB serial adapter and your MAX232 board). Note, also, that the UART pins on the TM4C232 part are 3.3V pins.

Have you made sure that your MAX232 circuit is working correctly? Use an oscilloscope to check that characters sent from UART7 appear on the relevant input and output pins of the MAX232 and also make sure that characters sent from the PC are also correctly handled. Are the serial RX signals correct at the TM4C232 pins?

You originally mentioned that you tried the uart_echo binary from the TivaWare release and that this didn't work for you. That suggests either that you have a problem with the serial port driver on the PC, your Hyperterminal is not configured to talk to the correct COM port, or there is a hardware problem with your LaunchPad. You need to investigate these three and make sure that the hardware and PC-side software is correct.

Hi Dave,

I have a similar problem with the EK-TM4C1294. I searched C:\ti\TivaWare_C_Series-2.1.1.71\examples\boards\ek-tm4c1294xl\uart_echo and C:\ti\TivaWare_C_Series-2.1.0.12573\examples\boards\ek-tm4c1294xl\uart_echo but found no uart_echo.bin. Please advise.

@Otto and (other) "Dave fans"

Dave - along w/many others - has, "Left the building."

Interestingly - there had been two, "Dave Wilsons" @ this vendor.   ( that head count now stands @ 1.)

Vendor's current expert - Amit Ashara - is superb  (and remains, "In the building"...)