Sensors: HX711

</nowiki> /*

gurov was here, use this code, or don't, whatever, I don't care. If you see a giant bug with a billion legs, please let me know so it can be squashed

gcc -o hx711wp hx711wp.c -lwiringPi

• /

1. include <stdint.h>
2. include <sys/types.h>

1. include <stdio.h>
2. include <sched.h>
3. include <string.h>
4. include <stdlib.h>
5. include <wiringPi.h>
6. include "locking.h"

1. define CLOCK_PIN 5
2. define DATA_PIN 4
3. define N_SAMPLES 64
4. define SPREAD 10

1. define SCK_ON (GPIO_SET0 = (1 << CLOCK_PIN))
2. define SCK_OFF (GPIO_CLR0 = (1 << CLOCK_PIN))
3. define DT_R (GPIO_IN0 & (1 << DATA_PIN))

void reset_converter(void); unsigned long read_cnt(long offset, int argc); void set_gain(int r); void setHighPri (void); int data_pin = DATA_PIN; int clock_pin = CLOCK_PIN;

void setHighPri (void) {

 struct sched_param sched ;

 memset (&sched, 0, sizeof(sched)) ;

 sched.sched_priority = 10 ;
 if (sched_setscheduler (0, SCHED_FIFO, &sched))
   printf ("Warning: Unable to set high priority\n") ;

}

static uint8_t sizecvt(const int read) {

   /* digitalRead() and friends from wiringpi are defined as returning a value
      < 256. However, they are returned as int() types. This is a safety function */

   if (read > 255 || read < 0)
   {
       printf("Invalid data from wiringPi library\n");
       exit(EXIT_FAILURE);
   }
   return (uint8_t)read;

}

void power_down_hx711() {

   digitalWrite(clock_pin, HIGH);

}

void setup_gpio() {

   pinMode(clock_pin, OUTPUT);
   pinMode(data_pin, INPUT);
   digitalWrite(clock_pin, LOW);

}

int main(int argc, char **argv) {

   int lockfd;
   int iPin = 0;
   int iErr = 0;
   char cMode = 'V';
   int iReturnCode = 0;

 int i, j;
 long tmp=0;
 long tmp_avg=0;
 long tmp_avg2;
 long offset=0;
 float filter_low, filter_high;
 float spread_percent = SPREAD / 100.0 /2.0;
 int b;
 int nsamples=N_SAMPLES;
 long samples[nsamples];

 if (argc == 2) {
  offset = atol(argv[1]);
 }
 if (argc == 4){
  clock_pin = atol(argv[1]);
  data_pin = atol(argv[2]);
  offset = atol(argv[3]);
 }

// lockfd = open_lockfile(LOCKFILE);

       iErr = wiringPiSetup ();
   if (iErr == -1)
       {
               if (cMode == 'V')
                       printf ("ERROR : Failed to init WiringPi %d\n", iErr);
       iReturnCode = -1;
       }

 setHighPri();
 setup_gpio();

// reset_converter();

 j=0;

 // get the dirty samples and average them
 for(i=0;i<nsamples;i++) {
// 	reset_converter();
//       reset_converter();
 	samples[i] = read_cnt(0, argc);
 	tmp_avg += samples[i];
 }

 tmp_avg = tmp_avg / nsamples;

 tmp_avg2 = 0;
 j=0;

 filter_low =  (float) tmp_avg * (1.0 - spread_percent);
 filter_high = (float) tmp_avg * (1.0 + spread_percent);

// printf("%d %d\n", (int) filter_low, (int) filter_high);

 for(i=0;i<nsamples;i++) {

if ((samples[i] < filter_high && samples[i] > filter_low) ||

           (samples[i] > filter_high && samples[i] < filter_low) ) {

tmp_avg2 += samples[i]; j++; }

 }

 if (j == 0) {
   printf("No data to consider\n");
   exit(255);

 }
 printf("%d\n", (tmp_avg2 / j) - offset);

// printf("average within %f percent: %d from %d samples, original: %d\n", spread_percent*100, (tmp_avg2 / j) - offset, j, tmp_avg - offset); // unpull_pins(); // restore_io(); // power_down_hx711(); }

void reset_converter(void) {

         digitalWrite(clock_pin, HIGH);
         delayMicroseconds(40);
         digitalWrite(clock_pin, LOW);
         delayMicroseconds(60);

}

void set_gain(int r) { int i;

// r = 0 - 128 gain ch a // r = 1 - 32 gain ch b // r = 2 - 63 gain ch a

       while( sizecvt(digitalRead(data_pin)) );

for (i=0;i<24+r;i++) {

         digitalWrite(clock_pin, HIGH);
         delayMicroseconds(1);
         digitalWrite(clock_pin, LOW);
         delayMicroseconds(1);

} }

unsigned long read_cnt(long offset, int argc) { long count; int i;

 count = 0;

 while( sizecvt(digitalRead(data_pin)) );
       digitalWrite(clock_pin, LOW);
       delayMicroseconds(.2);

 for(i=0;i<24	; i++) {
       digitalWrite(clock_pin, HIGH);
       delayMicroseconds(.2);
       count = count << 1;
       if ( sizecvt(digitalRead(data_pin)) > 0 )  { count++; }
       digitalWrite(clock_pin, LOW);
       delayMicroseconds(.2);
       }

       digitalWrite(clock_pin, HIGH);
       delayMicroseconds(.2);
       digitalWrite(clock_pin, LOW);
       delayMicroseconds(.2);

// count = ~0x1800000 & count; // count = ~0x800000 & count;

if (count & 0x800000) {

count |= (long) ~0xffffff;

}

// if things are broken this will show actual data

if (argc < 2 ) {

for (i=32;i;i--) {
  printf("%d ", ((count-offset) & ( 1 << i )) > 0 );
 }

 printf("n: %10d     -  ", count - offset);
 printf("\n"); 

}

 return (count - offset);

}

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