DE10/DE15に使用されるMC45A主幹制御器などからノッチを読み取るやつ(PIC16F1579向け)

mascon_read.c

// PIC16F1579 Configuration Bit Settings

// CONFIG1
#pragma config FOSC = INTOSC    // Oscillator Selection Bits (INTOSC oscillator; I/O function on CLKIN pin)
#pragma config WDTE = OFF       // Watchdog Timer Enable (WDT disabled)
#pragma config PWRTE = ON       // Power-up Timer Enable (PWRT enabled)
#pragma config MCLRE = OFF      // MCLR Pin Function Select (MCLR/VPP pin function is digital input)
#pragma config CP = OFF         // Flash Program Memory Code Protection (Program memory code protection is disabled)
#pragma config BOREN = ON       // Brown-out Reset Enable (Brown-out Reset enabled)
#pragma config CLKOUTEN = OFF   // Clock Out Enable (CLKOUT function is disabled. I/O or oscillator function on the CLKOUT pin)

// CONFIG2
#pragma config WRT = OFF        // Flash Memory Self-Write Protection (Write protection off)
#pragma config PPS1WAY = ON     // PPSLOCK bit One-Way Set Enable bit (PPSLOCKED Bit Can Be Cleared & Set Once)
#pragma config PLLEN = OFF       // PLL Disabled
#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will cause a Reset)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.)
#pragma config LPBOREN = OFF    // Low Power Brown-out Reset enable bit (LPBOR is disabled)

#define _XTAL_FREQ 16000000

#include <xc.h>
#include <stdio.h>

void putch(char write_char)
{
    while(!TXSTAbits.TRMT);
    TXREG = write_char;
}

void main(void)
{
    OSCCON = 0b01111011; // 16MHz
    
    ANSELC = 0b00000000; // All digital
    TRISC = 0b11111111; // PORTC all input
    PORTC = 0b00000000; // PORTC init
    
    ANSELB = 0b00000000;
    TRISB = 0b00010000; // RB4 input
    PORTB = 0b00000000;
    
    TRISA = 0b00000000;
    RA0PPS = 0b00001001; // RA0 UART TX
    TXSTA = 0b00100000; // 8bit UART
    RCSTA = 0b10010000;
    SPBRG = 25; // 16MHz 9600bps
    INTCONbits.GIE = 1; // accept interrupt
    PIE1bits.TXIE = 1; // accept TX interrupt
    
    unsigned char mascon = 0;
    unsigned char txbyte;
    
    while (1) {
        if (PORTCbits.RC3 == 1 && (PORTC & 0b00010111)) { // 18????ON
            mascon = (PORTCbits.RC4 << 3) + (PORTC & 0b00000111) - 1;
        } else {
            mascon = 0;
        }
        
        txbyte = (PORTC & 0b11100000) + (PORTBbits.RB4 << 4) + mascon;
        
        putch("%c", txbyte);
        while(!TXSTAbits.TRMT);
        __delay_ms(100);
    }
    
    return;
}