No subject

93.2ms not 100ms now.


Why is it incorrectly operate?
Our project must integrate sensor value with time. Thus exact conversion
period is important.


implementation
{


   const msp430adc12_channel_config_t config = {

    INPUT_CHANNEL_A0, REFERENCE_AVcc_AVss, REFVOLT_LEVEL_NONE,
    SHT_SOURCE_SMCLK, SHT_CLOCK_DIV_1, SAMPLE_HOLD_64_CYCLES,
    SAMPCON_SOURCE_SMCLK, SAMPCON_CLOCK_DIV_1

   };

  event void Boot.booted()
  {
    call Resource.request(); //from adc test

  }
    ///////////////////////////////////////////////////
  adc12memctl_t memctl[16];
  uint8_t numMemctl;
  #define ADCNUMS 5
  #define NUM_SAMPLES 50
  uint16_t buffer[NUM_SAMPLES];

  event void Resource.granted()
  {
    error_t result;
    uint8_t i;

    for(i=0; i<ADCNUMS-1; i++){
     memctl[i].inch=i+1; //List of additional channels
     memctl[i].sref=REFERENCE_AVcc_AVss;
    }

    numMemctl = ADCNUMS - 1;//chs - 1

    //1000000 MCLK / 500 sample per sec for all chs = 2000.
    result = call MultiChannel.configure(&config, memctl, numMemctl, buffer,
NUM_SAMPLES, 2000);

    if (result == SUCCESS){
      call MultiChannel.getData();
    }
    else{

    }

  }


//This must be called every 100ms. 10hz.
       //But now it is called 93.2ms every.!!! Why?
  async event void MultiChannel.dataReady(uint16_t *buf, uint16_t
numSamples)
  {
call Leds.led1Toggle(); //check by oscilloscope LED1 pin.

call MultiChannel.getData(); //call next conversion sequence...

  }

best regards,
K.S.Lee

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<p>Hi all,</p>
<p><br>I am working with Msp430Adc12MultiChannel interface.<br>But it has p=
roblem about conversion period.</p>
<p><br>It has 5 sensors which is assigned to from A0 to A4. Conversion peri=
od for each channel is <br>100hz and all channels have same configuration.<=
br>Thus a ADC into MSP430 will convert 500 per second.<br>To check ADC conv=
ersion complete timing I have used oscilloscope and LED1 pin.<br>