Problem with Serial

[Tectu]

@skute: I must have misunderstood something then. I thought this one works:

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chprintf(....);
while(1);

while this doesn't:

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while(1)
    chprintf(.....);

Edit: I just read back your first post where you mentioned that the //while(TRUE) causes the problem, skute. I totally meant you mean that the while(TRUE) does cause the problem, but you obviously tell that the problem is that it's commented-out. I'm sorry for the trouble!
I have missed the // part. I completely agree with you at all your points, skute ^^


~ Tectu

[M.H.Roohi]

hi ALL
@Giovanni: I don't know witch stack i should check? and where is it?
the problem is not from USART timing.
@Skute: your right that it takes 1ms for data to come out but when i use following format there is no problem:

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while(1)
   print(....);

but following format has problem:

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while(1) {
    print(.....);
    wait();
}

[M.H.Roohi]

hi
i have another problem that is more important for me
the following code is OK except in one situation:

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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "ch.h"
#include "hal.h"
#include "chprintf.h"

/* Total number of channels to be sampled by a single ADC operation.*/
#define ADC_GRP1_NUM_CHANNELS   2

/* Depth of the conversion buffer, channels are sampled four times each.*/
#define ADC_GRP1_BUF_DEPTH      1
static WORKING_AREA(Sampler, 128);
static WORKING_AREA(SampleSender, 128);
/*
 * ADC samples buffer.
 */
static adcsample_t samples[ADC_GRP1_NUM_CHANNELS * ADC_GRP1_BUF_DEPTH];

/*
 * ADC conversion group.
 * Mode:        Linear buffer, 4 samples of 2 channels, SW triggered.
 * Channels:    IN11   (480 cycles sample time)
 */
static const ADCConversionGroup adcgrpcfg = {
  FALSE,
  ADC_GRP1_NUM_CHANNELS,
  NULL,
  NULL,
  /* HW dependent part.*/
  0,
  ADC_CR2_SWSTART,
  ADC_SMPR1_SMP_AN11(ADC_SAMPLE_480)|ADC_SMPR1_SMP_AN10(ADC_SAMPLE_480),
  0,
  ADC_SQR1_NUM_CH(ADC_GRP1_NUM_CHANNELS),
  0,
  ADC_SQR3_SQ1_N(ADC_CHANNEL_IN11)|ADC_SQR3_SQ2_N(ADC_CHANNEL_IN10)
};
static msg_t ADCSampler(void *arg){
   systime_t time = chTimeNow();
   while(TRUE){
      time += MS2ST(10);
      chSysLockFromIsr();
    adcStartConversionI(&ADCD1, &adcgrpcfg, samples, ADC_GRP1_BUF_DEPTH);
    chSysUnlockFromIsr();
      chThdSleepUntil(time);
   }
}
static msg_t USARTSampleSender(void *arg){
   systime_t time = chTimeNow();
   while(TRUE){
      time += MS2ST(10);
      chprintf((BaseChannel *)&SD2, "%D\r\n",samples[1]);
      chThdSleepUntil(time);
   }
}
int main(void){
  /*
   * Shell thread
   */
  halInit();
  chSysInit();
    /*
   * Initializes the ADC driver 1 and enable the thermal sensor.
   */
  adcStart(&ADCD1, NULL);
  palSetGroupMode(GPIOC,PAL_PORT_BIT(1) | PAL_PORT_BIT(0),0,PAL_MODE_INPUT_ANALOG);
   
   sdStart(&SD2, NULL);
  palSetPadMode(GPIOA, 2, PAL_MODE_ALTERNATE(7));
  palSetPadMode(GPIOA, 3, PAL_MODE_ALTERNATE(7));
   (void)chThdCreateStatic(Sampler, sizeof(Sampler), NORMALPRIO, ADCSampler, NULL);
   (void)chThdCreateStatic(SampleSender, sizeof(SampleSender), NORMALPRIO, USARTSampleSender, NULL);
while(1){
  //chprintf((BaseChannel *)&SD2, "%CH2: %D\r\n",(samples[0]));

}
}

in the following part of code if i decrease the delay in (time += US2ST(10);) the program will not work. i red (Reliable timings using Threads) article and i know that for this code to work the program time should be less than the delay but with the rate of 921600 it takes about 0.026 (ms) for USART to send out the data!

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static msg_t USARTSampleSender(void *arg){
   systime_t time = chTimeNow();
   while(TRUE){
      time += MS2ST(10);
      chprintf((BaseChannel *)&SD2, "%D\r\n",samples[1]);
      chThdSleepUntil(time);
   }
}

[Giovanni]

You can't have delays of 10uS that way, the system counter resolution is 1mS. The result of the US2ST() macro is approximated to the next system tick, 1mS in you case.

Giovanni

[M.H.Roohi]

You can't have delays of 10uS that way, the system counter resolution is 1mS. The result of the US2ST() macro is approximated to the next system tick, 1mS in you case.

Giovanni

excuse me i change the delay to US just for fun (test!) now i correct the above POST Mr Giovanni