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how to do UART transmission from keyfob to pc

aaji
Prodigy 70 points
Other Parts Discussed in Thread: CC2540

I want to transmit data from keyfob to pc..

i have attached my code here..

i modified keyfob demo example with uart application ..

can u tell me how to transmit data to PC..?...

i set the port1.4 &1.5 for tx and rx enable to connect pc using rs232 to usb cable 

 

 

 

  P1SEL = 0x30; // Configure Port 1 as GPIO, except P1.4 and 1.5for peripheral function for UART

  P1DIR = 0xFF; // All port 1 pins (P1.0-P1.7) as output

 

  P1 = 0;   // All pins on port 1 to low

 

  // initialize the ADC for battery reads

 

  HalUARTInit();

 

 

  //Initialize ADC with internal 1.25V set as reference

  HalAdcSetReference( HAL_ADC_REF_125V );

 

  // Read the ADC

  adc_read = HalAdcRead( HAL_ADC_CHANNEL_VDD, HAL_ADC_RESOLUTION_10 );

 

  /*****************************************************************************  

   *

   *  the ADC takes in one-third of VDD as its input and has a 1.25V reference

   *  An adc_read value of 0 corresponds to 0V at the ADC input, and a value

   *  of 511 corresponds to 1.25V at the ADC input (with 10 bit resolution).

   * 

   *  The CC2540 requires 2.0V at VDD to operate according to the specification.

   *  Therefore, we will define 2.0V as 0% battery level, and 3.0V as 100% battery

   *  level. Therefore the simple formula for battery percentage is:

   * 

   * (Battery Percentage) = ((Battery Voltage) - 2.0) * 100

   *

   * From a software standpoint, the following calculation can be used to get the

   *  battery percentage:

   *  

   * With a 3V battery, we can approximate percentage by multiplying the ADC result

   * by 375, dividing by 511, and subtracting that result by 200. The value will not

   * be exact, due to the rounding of integer values, but should be within one percent.

   *

   * For example, if the battery voltage is 2.7V, the battery percentage should

   * be 70% ((2.7-2.0)*100 = 70). The ADC input will be one-third of the input (0.9V).

   * This will result in an adc_read value of 367 (0.9/1.25 * 511 = 367). If we apply

   * the calculation used by the software:

   *

   * ( (367 * 375) / 511 ) - 200 = 69

   *

   * This is within one percent of the actual value of 70%.

   *

   */

 

  adc_read_times_375 = (uint32)adc_read * (uint32)(375);

  batteryLevel_current_read = (uint8) ( (adc_read_times_375 / (uint32)(511)) - (uint32)(200) );

 

  /*****************************************************************************

   *

   * in a discharging battery state, the battery level can still fluctuate up

   * and down slightly over time, so we only want to change the battery level attribute

   * if it has dropped.

   *

   */

 

  if( batteryLevel_current_read < batteryLevel )

    batteryLevel = batteryLevel_current_read;

 

  if( batteryLevel < BATTERY_LEVEL_CRITICAL_PCT )

    batteryState = BATTERY_STATE_CRITICAL_REPLACE_NOW;

  else

    batteryState = BATTERY_STATE_DISCHARGING;

    HalUARTWrite(1,&batteryLevel,1);

 

   osal_msg_send( HR_TaskID, &batteryLevel);

 

  // Update the Battery Profile

 // Battery_SetParameter( BATTERY_ATTR_LEVEL, sizeof ( uint8 ), &batteryLevel );

 // Battery_SetParameter( BATTERY_ATTR_STATE

 

 

 

  • 0
    TI__Guru 57865 points

    In order to to use P1.4 and P1.5 for UART you will need to use Usart 0 alternative 2 by adding register set: 

    PERCFG |= 0x01;

    Also try

    P1DIR = 0xEF; //Set P1.4 to input, others to output 

    Note that P1.5 is TX and P1.4 is RX. See http:// www.ti.com/lit/swru191 for more information.

  • 0 in reply to J Lindh
    Prodigy 70 points

    thanks for reply 

    i enable  p1.4 as i/p and p1.5 o/p ..

    if i connect p1.5 to serial cable to hyperterminal..

    i didn't get no data..

    can u send me the sample code for uart...

     

     

  • 0 in reply to aaji
    TI__Guru 57865 points

    Based on the code you attached above, I believe you should also open the port before you write to the UART. This is done by the HalUARTOpen() function.

    For example, 

     

    halUARTCfg_t = config;

    config.configured = true;

    config.baudRate = HAL_UART_BR_38400;

    config.flowControl = false;

    config.flowControlThreshold = 64;

    config.idleTimeout = 6;

    config.rx.maxBufSize = 128;

    config.tx.maxBufSize = 128;

    config.intEnable = false;

    config.callBackFunc = NULL;


    HalUARTOpen(HAL_UART_PORT_1, &config);

     

    You can read more about this in the Hal Driver API, found in you BLE installation folder (..\Texas Instruments\BLE-CC2540\Documents\hal).

  • 0 in reply to J Lindh
    Intellectual 340 points

    I have been trying to get the CC2540 mini DK key fob to communicate to a PC and ran into a lot of road blocks.  But I was finally able to get it running.  I am very new to embedded development so this might be obvious to everyone else but this is what I got stumped on.

    The CC2540 uses TTL to signal, you need to convert it to a rs232 signal using a chip like a MAX-232.

    The sample projects are missing the following preprocessor definitions

    HAL_UART
    
HAL_UART_ISR=2
    
HAL_UART_ISR_RX_MAX=250
    
There is some confusion as to what HAL_UART_ISR should be set to...

    The HAL layer in the sample projects don't deal well with the UART.  
    The HAL set UART1 to ALT 2 which outputs to P1_6. P1_6 is connected the send to the speaker. Every time I wrote to the UART it beeped at me. :)
    I had to make about 10-20 changes in the HAL code to get the UART to work correctly. Maybe I have an old copy? I can give a more detailed description of the changes if people like.

    It took me forever to find the key fob layout schematic.  I had no idea which pins had which gpio on it.  the schematic is in swrr071a.zip.
  • 0 in reply to Andrew Shaw
    Intellectual 340 points

    I also had to disable power management.  I could write out to the serial port but reading from the serial port was spotty at best, until I turned off power management.  works great now.  There is probably a bad interupt mask somewhere in the code.

  • 0 in reply to J Lindh
    Prodigy 10 points

    Nick L said:

    config.callBackFunc = NULL;

    Hi Nick,

    I am having trouble understanding how callBackFunc is set to a specific function, what is the syntax for doing so?

    Thanks,
    Alex

  • 0 in reply to Alex Forward1
    TI__Genius 12900 points

    config.callBackFunc is a function pointer (taking 2 arguments?) if I remember correctly.

    So, if your callback function is

    void myCallBackFunction(uint8 a, uint8 b) { ... }

    , you map your callback function to the UART configuration like this:

    config.callBackFunc = &myCallBackFunction;

    The value of config.callBackFunc is the address where myCallBackFunction is stored.

    Br,
    ABO 

  • 0 in reply to Andrew Shaw
    Prodigy 10 points

    hi andrew , i am very interested in your solution to the problem
    above could share your solution with me, since ja thank