encoder.cpp

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <iostream>
#include <string.h>
#include <math.h>
#include <wiringPi.h>
#include <wiringPiSPI.h>

using namespace std;

const int BYTE_len=4;
const int SPI_CHANNEL=1;
unsigned char rawData[BYTE_len];
unsigned char rawData_delayed[BYTE_len];
float count;
float clock_count;
float count_delayed;
float speed;
int freq=500000;
int res = 2048;
int main(int argc, char const *argv[])
{   
    
    rawData_delayed[0]=0x00;
    rawData_delayed[1]=0x00;
    rawData_delayed[2]=0x00;
    rawData_delayed[3]=0x00;

    if (wiringPiSetup() == -1) {
        printf("WiringPiSetup failed\n");
        exit(EXIT_FAILURE);
    }

    //memset(rawData,0x01,BYTE_len);
    //rawData[0]=0x0F;
    rawData[3]=0x00;
    rawData[2]=0x00;
    rawData[1]=0x00;
    rawData[0]=0x00;
    int fd = wiringPiSPISetup(SPI_CHANNEL, 500000);

    //for (int i=0; i<4; i++){
           //printf("%02X \n", rawData[i]); 
        //}

   while(1) { 
        int result = wiringPiSPIDataRW(SPI_CHANNEL, rawData, BYTE_len);
        printf("\r%d %d %d %d", rawData[0], rawData[1], rawData[2], rawData[3]); 
        fflush(stdout);
        //printf("\n");
        count=(rawData[0]*pow(16, 4))+(rawData[1]*pow(16, 2))+(rawData[2]*pow(16, 0));
        
        speed=freq*(2*3.1415/res)*(count-count_delayed);
        //printf("\r%lf", count); 
        //fflush(stdout);
        count_delayed=count;
        //printf("\n");
        //sleep(0.5);
    }
       
    return 0;
    
}