// Lab 4 - RS-232 Serial Interface Waveform
// Troy Dowling, A00817082
// 2015-10-05

#include <stdio.h>
#include <stdbool.h>
#include <inttypes.h>

#define BAUD_RATE_HZ        9600
#define SAMPLE_RATE_HZ      38400
#define SAMPLES_PER_PULSE   (SAMPLE_RATE_HZ / BAUD_RATE_HZ)

#define MARKL           0x00
#define MARKH           0x00
#define SPACEL          0xFF
#define SPACEH          0x3F

void tputw(bool input)
{
        if(input)
        {
            // Mark
            for(int i = SAMPLES_PER_PULSE; i; i--)
            {
                putc(MARKL, stdout);
                putc(MARKH, stdout);
            }
        }
        else
        {
            // Space
            for(int i = SAMPLES_PER_PULSE; i; i--)
            {
                putc(SPACEL, stdout);
                putc(SPACEH, stdout);
            }
        }
}

int main(void)
{
    // This is the string to pipe out over UART
    char str[] = "Troy Dowling A00817082\r\n";

    // For each character in the string
    for(int i = 0; i < sizeof(str)/sizeof(str[0]); i++)
    {
        // Output start bit
        tputw(false);

        // Output each bit in the character
        uint8_t mask = 0x01;
        for(int i = 0; i < 8; i++)
        {
            if(str[i] & mask)
                tputw(true);
            else
                tputw(false);
            mask <<= 1;
        }

        // Output the stop bit
        tputw(true);
    }

    return 0;
}