UART malfunction upon communication with SHT10 sensor

Hi Jose!

I've carried out another experiment with the SHT10 sensor and found out that when I read measurements off of it using the sht1x_update() function (from the libupm library I mentioned before), the 0-13 GPIO pins receive noise.

However, there is no noise on pins 14-19. There is NOTHING connected to the pins apart from the sensor itself.

In the test program below, the SHT10 sensor is connected to the 19th and 18th pins, but the results will not change if I connect it to other pins.

Here's a link to the SHT10 brick itself: Electronic Brick - SHT10 Temperature Humidity Sensor

unsigned int  SigStop = 1;

void* digit (void *val)

{

     unsigned int i;

     mraa_gpio_context gpio;

  gpio = mraa_gpio_init(2);

     mraa_gpio_dir(gpio, MRAA_GPIO_IN);

      while (SigStop) {

     i = mraa_gpio_read(gpio);

           if(i){fprintf(stdout, "\nGpio is %d", i);  }

           usleep(100000);

      }

      printf ("\nStop Signal in Thread\n");

      for(i=0; i<10; i++) {

          fprintf(stdout, "\nGpio is %d", mraa_gpio_read(gpio));

          usleep(100000);

      }

  i = mraa_gpio_close(gpio);

     printf ("\nThread Ended\n");

      pthread_exit(0);

}

int main()

{

     unsigned int i,er;

     pthread_t proc_hnd;

     if(pthread_create(&proc_hnd, 0, *digit, &i))

     {

          printf ("\nNO THREAD");

          return 0;

     }

     sht1x_context sensor = sht1x_init (19,18);

     if (!sensor){

          printf("sht1x_init() failed.\n");

          return 0;

     }

     for (i=0; i<3; i++){

          sleep(2);

          printf("\nBegin Update");

    er = sht1x_update(sensor);

          if(er != 0){printf("sht1x_update() failed, exiting.\n"); break;}

          printf ("\nTemperature: %.2f C\n", sensor->temperature);

          printf ("Humidity: %.2f RH\n", sensor->humidity);

          fflush(stdout);

     }

     sht1x_close(sensor);

     sleep(2);

     SigStop = 0;

     sleep(2);

     return 0;

}

Here are the results which it prints out:

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Begin Update

Gpio is 1

Gpio is 1

Gpio is 1

Temperature: 37.52 C

Humidity: 29.48 RH

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Begin Update

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Temperature: 26.43 C

Humidity: 28.82 RH

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Begin Update

Gpio is 1

Gpio is 1

Gpio is 1

Temperature: 24.50 C

Humidity: 31.47 RH

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Gpio is 1

Stop Signal in Thread

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Gpio is 0

Thread Ended

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