/* @brief This is a simple application for testing IIC communication on a RedPitaya
 * @Author Luka Golinar <luka.golinar@redpitaya.com>
 * 
 * (c) Red Pitaya  http://www.redpitaya.com
 *
 * This part of code is written in C programming language.
 * Please visit http://en.wikipedia.org/wiki/C_(programming_language)
 * for more details on the language used herein.
 */

 
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/ioctl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
 #include <math.h>
#define I2C_SLAVE_FORCE            0x0706
#define EXPANDER_ADDR                  0x20
 

int main(int argc, char *argv[])
{
//int main(){
//int k;

//for (k=0;k<=5;k++)
//{
 
sleep(3);
//printf("%i\n", k );
    
    int  dat;
    int  fd; 
    int  status;
    char str [1+2*11];

    //parse input arguments
    dat = (int)strtol(argv[1], NULL, 0);

    dat = (1<<dat);

    // Open the device.
    fd = open("/dev/i2c-0", O_RDWR);
    if (fd < 0) {
        printf("Cannot open the IIC device\n");
        return 1;
    }

    // set slave address
    status = ioctl(fd, I2C_SLAVE_FORCE, EXPANDER_ADDR);
    if (status < 0) {
        printf("Unable to set the I2C address\n");
        return -1;
    }

    // Write to expander
    str [0] = 0; // set address to 0
    str [1+0x00] = 0x00; // IODIRA - set all to output
    str [1+0x01] = 0x00; // IODIRB - set all to output
    str [1+0x02] = 0x00; // IPOLA
    str [1+0x03] = 0x00; // IPOLB
    str [1+0x04] = 0x00; // GPINTENA
    str [1+0x05] = 0x00; // GPINTENB
    str [1+0x06] = 0x00; // DEFVALA
    str [1+0x07] = 0x00; // DEFVALB
    str [1+0x08] = 0x00; // INTCONA
    str [1+0x09] = 0x00; // INTCONB
    str [1+0x0A] = 0x00; // IOCON
    str [1+0x0B] = 0x00; // IOCON
    str [1+0x0C] = 0x00; // GPPUA
    str [1+0x0D] = 0x00; // GPPUB
    str [1+0x0E] = 0x00; // INTFA
    str [1+0x0F] = 0x00; // INTFB
    str [1+0x10] = 0x00; // INTCAPA
    str [1+0x11] = 0x00; // INTCAPB
    str [1+0x12] = (dat >> 0) & 0xff; // GPIOA
    str [1+0x13] = (dat >> 8) & 0xff; // GPIOB
    str [1+0x14] = (dat >> 0) & 0xff; // OLATA
    str [1+0x15] = (dat >> 8) & 0xff; // OLATB
    status = write(fd, str, 1+2*11);

    //printf("Resistor data write = 0x%04x.\n", dat);
   // if (status)  printf("Resistor write => %.1f\n", powf(10.0,(float)k+1));
    //else         
     //   printf("Error write\n");
    

    close(fd);

//}
    return 0;

}