/*
 * Introduction to Atmel microcontrollers demo program.
 *
 * This program demonstrates simple I/O (input-output) using switches and LEDs,
 * as well as how to do character output through the UART to HyperTerminal on a
 * PC.
 *
 * Last modified 2010-09-02 22:26
 */
#include <avr/io.h>    // for PORTx, PINx, DDRx, etc.
#include <stdio.h>     // for printf()
#include "uart.h"      // for uart_init() (implementation(s) in uart.c)

/* forward declarations (functions used before they are defined) */
void printf_example(void);

/*
 * All one-time initializatons should be put here in init() to keep main()
 * manageable/readable.
 */
void init(void)
{
    DDRA  = 0x00;  // configure all 8 bits of PORTA as inputs
    DDRB  = 0xFF;  // configure all 8 bits of PORTD as outputs

    uart_init();
}

int main(void)
{
    init();   // do the one-time initializations

    printf_example();

    while (1)
    {
        PORTB = PINA; // have PORTB outputs reflect PINA inputs
    }

    return 0;  // never executed...
}

/*
 * The statements in this function provide a few examples on how to use printf() for output
 * formatting with various data types.  For more information about how to use avr-libc's
 * version of printf(), see:
 *   http://www.nongnu.org/avr-libc/user-manual/group__avr__stdio.html
 *
 * In short, for each datum to be displayed, a format specifier (a %<something> element)
 * must be provided in the format string (the first parameter), along with the datum
 * itself in the parameter list.
 */
void printf_example(void)
{
    char     aChar = 'Z', aCharInASCII=65;
    char     aString[] = "Mr. String.";
    uint8_t  the_answer = 42;
    uint16_t days_in_year = 365;
    uint32_t jenny = 8675309;
    double   pi = 3.14159265358979323846;

    printf("The character '%c' occurs two times in the string \"%s\",\r\nwhereas '%c' doesn't.\r\n",
           aChar , aString, aCharInASCII);
    printf("An 8bit unsigned int in decimal format: %u\r\n", the_answer);
    printf("An 8bit unsigned int in hexadecimal format: %X\r\n", the_answer);
    printf("A 16bit unsigned int: %u\r\n", days_in_year);
    printf("A 32bit unsigned int: %lu\r\n", jenny);
    printf("A 32bit floating point number: %f, and less accurately: +%6.2f: \r\n", pi, pi);
}