//
// hello.bluetooth.c
//
// 16E5 dac
//

#include <avr/io.h>
#include <util/delay.h>
#include <avr/pgmspace.h>

#define output(directions,pin) (directions |= pin) // set port direction for output
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin
#define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set
#define bit_delay_time 8.5 // bit delay for 115200 with overhead
#define bit_delay() _delay_us(bit_delay_time) // RS232 bit delay
#define half_bit_delay() _delay_us(bit_delay_time/2) // RS232 half bit delay
#define char_delay() _delay_ms(10) // char delay

#define VPORTA VPORT0 // pre-mapped virtual port A
#define VPORTC VPORT1 // pre-mapped virtual port C
#define VPORTD VPORT2 // pre-mapped virtual port D
#define VPORTR VPORT3 // pre-mapped virtual port R


#define serial_port VPORT2.OUT
#define serial_direction VPORT2.DIR
#define serial_pins VPORT2.IN
#define serial_pin_in PIN6_bm //RX
#define serial_pin_out PIN7_bm //TX


#define blue_port VPORT1.OUT
#define blue_direction VPORT1.DIR
#define blue_pins VPORT1.IN
#define blue_pin_in PIN2_bm //RX
#define blue_pin_out PIN3_bm //TX

#define max_buffer 25


void get_char(volatile unsigned char *pins, unsigned char pin, char *rxbyte) {
    //
    // read character into rxbyte on pins pin
    //    assumes line driver (inverts bits)
    //
    *rxbyte = 0;
    while (pin_test(*pins,pin))
    //
    // wait for start bit
    //
    ;
    //
    // delay to middle of first data bit
    //
    half_bit_delay();
    bit_delay();
    //
    // unrolled loop to read data bits
    //
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 0);
    else
    *rxbyte |= (0 << 0);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 1);
    else
    *rxbyte |= (0 << 1);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 2);
    else
    *rxbyte |= (0 << 2);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 3);
    else
    *rxbyte |= (0 << 3);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 4);
    else
    *rxbyte |= (0 << 4);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 5);
    else
    *rxbyte |= (0 << 5);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 6);
    else
    *rxbyte |= (0 << 6);
    bit_delay();
    if pin_test(*pins,pin)
    *rxbyte |= (1 << 7);
    else
    *rxbyte |= (0 << 7);
    //
    // wait for stop bit
    //
    bit_delay();
    half_bit_delay();
}

void put_char(volatile unsigned char *port, unsigned char pin, char txchar) {
    //
    // send character in txchar on port pin
    //    assumes line driver (inverts bits)
    //
    // start bit
    //
    clear(*port,pin);
    bit_delay();
    //
    // unrolled loop to write data bits
    //
    if bit_test(txchar,0)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,1)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,2)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,3)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,4)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,5)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,6)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    if bit_test(txchar,7)
    set(*port,pin);
    else
    clear(*port,pin);
    bit_delay();
    //
    // stop bit
    //
    set(*port,pin);
    bit_delay();
    //
    // char delay
    //
    bit_delay();
}

void put_string(volatile unsigned char *port, unsigned char pin, char *str) {
    //
    // print a null-terminated string
    //
    static int index;
    index = 0;
    do {
        put_char(port, pin, str[index]);
        ++index;
    } while (str[index] != 0);
}

int get_string(volatile unsigned char *port, unsigned char pin, unsigned char *string, unsigned int length)
{
    int count=0;
    unsigned char chr;
    do{
        get_char(&serial_pins, serial_pin_in, string);
    }while(*string++!=13 && count++<length);
    *string=0;
    return count;
}


int main(void) {
    //
    // main
    //
    static char chr;
    static char buffer[max_buffer] = {0};
    uint8_t btconnect=0;
    //
    //
    // set up clock
    //
    OSC.CTRL = OSC_RC32MEN_bm; // enable 32MHz clock
    while (!(OSC.STATUS & OSC_RC32MRDY_bm)); // wait for clock to be ready
    CCP = CCP_IOREG_gc; // enable protected register change
    CLK.CTRL = CLK_SCLKSEL_RC32M_gc; // switch to 32MHz clock
    //
    // initialize output pins
    //
    set(serial_port, serial_pin_out);
    output(serial_direction, serial_pin_out);
    
    // initialize bluetooth pins
    set(blue_port, blue_pin_out);
    output(blue_direction, blue_pin_out);
    
    //wait for bluetooth connection
 //   do{
   //     put_string(&blue_port, blue_pin_out,"$$$\r");
     //   char_delay();
       // get_string(&blue_port, blue_pin_out,buffer, max_buffer);
    //}while (btconnect==0);
  //  put_string(&blue_port, blue_pin_out,"$$$\r");
 //   char_delay();

    
    
    //get_string(&serial_pins, serial_pin_in, &chr);
    while (1) {
       // put_string(&serial_port, serial_pin_out, "LISTENING:>\r");
        get_char(&serial_pins, serial_pin_in, &chr);
        if (chr=='a') {
            put_string(&blue_port, blue_pin_out,"$$$");
        //    char_delay();
         //   get_char(&blue_pins, blue_pin_in, &chr);
        //    put_char(&serial_port, serial_pin_out, chr);
            put_string(&serial_port, serial_pin_out, "LISTENING:>\r");
            char_delay();
            //get_char(&blue_pins, blue_pin_in, chr);
            //get_string(&blue_pins, blue_pin_in,buffer, max_buffer);
            //    put_string(&serial_port, serial_pin_out, buffer);
//put_string(&serial_port, serial_pin_out, "\r");
        }
        
        
     
        //get_string(&blue_pins, blue_pin_in,buffer, max_buffer);
        //char_delay();
        //put_string(&serial_port, serial_pin_out, buffer);
        //char_delay();
        
       // get_string(&blue_pins, serial_pin_in, &chr);
    }
}