How to change CC26xx/CC13xx UART baudrate dynamically in your application.

The following steps show you how to change CC26xx/CC13xx UART baudrate dynamically in your application.

1. In port pininterrupt example into your CCS.

2. Add the following header files for UART and task related stuffs.

    #include <ti/sysbios/knl/Task.h>
    #include <ti/drivers/UART.h>
    #include <stdint.h>

3. Add the following defines and global variables for UART and task related stuffs.

    #define TASKSTACKSIZE     768
    uint32_t baudrate=115200;
    bool baudrate_change=false;
    UART_Handle uart;
    UART_Params uartParams;

    Task_Struct task0Struct;
    Char task0Stack[TASKSTACKSIZE];

4. Add the following red codes into buttonCallbackFxn to change baudrate when BTN1 is pressed.

            case Board_BUTTON1:
                currVal =  PIN_getOutputValue(Board_LED1);
                PIN_setOutputValue(ledPinHandle, Board_LED1, !currVal);
                if(baudrate==115200){
                    const char echoBaudrateChange[] = "\fChange Baudrate to 9600:\r\n";
                    UART_write(uart, echoBaudrateChange, sizeof(echoBaudrateChange));
                    baudrate=9600;
                }else{
                    const char echoBaudrateChange[] = "\fChange Baudrate to 115200:\r\n";
                    UART_write(uart, echoBaudrateChange, sizeof(echoBaudrateChange));
                    baudrate=115200;
                }
                baudrate_change=true;                break;


5. Add the following function echoFxn()

Void echoFxn(UArg arg0, UArg arg1)
{
    char input;
    const char echoPrompt[] = "\fEchoing characters:\r\n";

    /* Create a UART with data processing off. */
    UART_Params_init(&uartParams);

RESTART_UART:
    uartParams.writeDataMode = UART_DATA_BINARY;
    uartParams.readDataMode = UART_DATA_BINARY;
    uartParams.readReturnMode = UART_RETURN_FULL;
    uartParams.readEcho = UART_ECHO_OFF;
    uartParams.baudRate = baudrate;
    uart = UART_open(Board_UART0, &uartParams);

    if (uart == NULL) {
        System_abort("Error opening the UART");
    }

    UART_write(uart, echoPrompt, sizeof(echoPrompt));

    /* Loop forever echoing */
    while (1) {
        if(baudrate_change){
            UART_close(uart);
            uart=NULL;
            baudrate_change=false;
            goto RESTART_UART;
        }
        UART_read(uart, &input, 1);
        UART_write(uart, &input, 1);
    }
}


6. Add the following red codes in main function to start UART task.

int main(void)
{
    Task_Params taskParams;
    /* Call board init functions */
    Board_initGeneral();
    Board_initUART();

    /* Construct BIOS objects */
    Task_Params_init(&taskParams);
    taskParams.stackSize = TASKSTACKSIZE;
    taskParams.stack = &task0Stack;
    Task_construct(&task0Struct, (Task_FuncPtr)echoFxn, &taskParams, NULL);...
}


7. Build and download firmware into LaunchPad to test it.

Using CC13xx/CC26xx running Contiki OS to toggle LED from UART.

The following example shows how to using CC13xx/CC26xx running Contiki OS to toggle LED from UART.

1. Replace the following code into hell-world.c

#include "contiki.h"
#include "dev/cc26xx-uart.h"
#include "dev/serial-line.h"
#include "dev/leds.h"

#include < stdio.h >/* For printf() */
#include  < string.h >

 PROCESS(test_serial, "Serial line test process");
 AUTOSTART_PROCESSES(&test_serial);

 PROCESS_THREAD(test_serial, ev, data)
 {
   PROCESS_BEGIN();
   cc26xx_uart_set_input(serial_line_input_byte);
  
   printf("Hello, world Serial line test\n");

   for(;;) {
     PROCESS_YIELD();
     if(ev == serial_line_event_message) {
       printf("received line: %s\n", (char *)data);
       if(strcmp(data,"ON")==0)
           leds_on(LEDS_GREEN);
       else if(strcmp(data,"OFF")==0)
           leds_off(LEDS_GREEN);
     }
   }
   PROCESS_END();
 }

2. Build hello-world.bin for LAUNCHXL-CC1310 using  "make TARGET=srf06-cc26xx BOARD=launchpad/cc1310 hello-world.bin"

3. Download hello-world.bin to LAUNCHXL-CC1310 using Flash Programmer 2.

4. Start a terminal tool like teraterm to connect to LAUNCHXL-CC1310 application virtual COM port..

5. Enter "ON" and "CTRL+Enter" to send ON command with end character "0x0A" to LAUNCHXL-CC1310 and you will see green led is turned on

6. Enter "OFF" and "CTRL+Enter" to send OFF command with end character "0x0A" to LAUNCHXL-CC1310 and you will see green led is turned on

How to use two UART ports in CC2530 Z-Stack

The following steps show how to use two UART ports in CC2530 Z-Stack

1. Define HAL_UART=TRUE, HAL_UART_ISR=1, and HAL_UART_DMA=2 in compile options.
2. Initialize and use UART0 (P0_2 as RX/P0_3 as TX)  as the followings:

void initUart0(halUARTCBack_t pf)
{
  halUARTCfg_t uartConfig;
  uartConfig.configured           = TRUE;
  uartConfig.baudRate             = HAL_UART_BR_115200;
  uartConfig.flowControl          = FALSE;
  uartConfig.flowControlThreshold = 48;
  uartConfig.rx.maxBufSize        = 128;
  uartConfig.tx.maxBufSize        = 128;
  uartConfig.idleTimeout          = 6; 
  uartConfig.intEnable            = TRUE;            
  uartConfig.callBackFunc         = pf;
  HalUARTOpen (HAL_UART_PORT_0, &uartConfig);
}

void uart0RxCb( uint8 port, uint8 event )
{
  uint8  ch;
  while (Hal_UART_RxBufLen(port))
  {
    // Read one byte from UART to ch
    HalUARTRead (port, &ch, 1);
  }
}

initUart0(uart0RxCb);

//Output "UART0 output test" to P0.3
HalUARTWrite( HAL_UART_PORT_0, "UART0 output test", (byte)osal_strlen("UART0 output test"));

3. Initialize and use UART1 (P1_6 as TX/P1_7 as RX) as the followings:

void initUart1(halUARTCBack_t pf)
{
  halUARTCfg_t uartConfig;
  uartConfig.configured           = TRUE;
  uartConfig.baudRate             = HAL_UART_BR_115200;
  uartConfig.flowControl          = FALSE;
  uartConfig.flowControlThreshold = 48;
  uartConfig.rx.maxBufSize        = 128;
  uartConfig.tx.maxBufSize        = 128;
  uartConfig.idleTimeout          = 6; 
  uartConfig.intEnable            = TRUE;            
  uartConfig.callBackFunc         = pf;
  HalUARTOpen (HAL_UART_PORT_1, &uartConfig);
}

void uart1RxCb( uint8 port, uint8 event )
{
  uint8  ch;
  while (Hal_UART_RxBufLen(port))
  {
    // Read one byte from UART to ch
    HalUARTRead (port, &ch, 1);
  }
}

initUart1(uart0RxCb);

//Output "UART1 output test" to P1.6
HalUARTWrite( HAL_UART_PORT_1, "UART1 output test", (byte)osal_strlen("UART1 output test"));