// PIC18 in C - Raspberry Pi code - Versione 0.1 - giugno 2016 
// Copyright (c) 2016, Vincenzo Villa
// Creative Commons | Attribuzione - Condividi allo stesso modo 4.0 Internazionale (CC BY-SA 4.0)
// Creative Commons | Attribution-Share Alike 4.0 Unported
// https://www.vincenzov.net/tutorial/PIC18/UART-MCC.htm    
// Raspberry Pi code - Serial comunication 

// Note:
//   Compile: gcc -Wall -std=c99 -o pic pic.c -lwiringPi
//   Remember: export WIRINGPI_GPIOMEM=1
//   Remember: enable UART in /boot/config.txt
//   Remember: disable serial terminal with raspi-config

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

#include <wiringPi.h>
#include <wiringSerial.h>

#define MAGIC 0xAA
#define PACK_SIZE 4

int main(void) {
    int fd;
    unsigned char dataToSend[PACK_SIZE];

    wiringPiSetup();

    dataToSend[0] = MAGIC;
    dataToSend[1] = 0x11;
    dataToSend[2] = 0x22;

    if ((fd = serialOpen("/dev/ttyAMA0", 115200)) < 0) {
        printf("Unable to open serial device: %s\n", strerror(errno));
        return 1;
    }

    while (1) {
        for (int j = 0; j < 6; j++) {
            dataToSend[3] = j;
            for (int i = 0; i < PACK_SIZE; i++)
                serialPutchar(fd, dataToSend[i]);

            usleep(100);


            if (serialDataAvail(fd) >= 4) {
                for (int i = 0; i < PACK_SIZE; i++)
                    printf("0x%X ", serialGetchar(fd));
                printf("\n");
            }

            sleep(1);
        }
    }

    serialClose(fd);
    return 0;
}