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/* Simple example for Teensy USB Development Board
* http://www.pjrc.com/teensy/
* Copyright (c) 2008 PJRC.COM, LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <stdint.h>
#include <util/delay.h>
#include "usb_serial.h"
#define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
void send_str(const char *s);
void send_int(unsigned int val);
uint8_t recv_str(char *buf, uint8_t size);
volatile unsigned int system_timer = 0;
int main(void)
{
int changed = 0, val;
int port = 'B' - 'A';
int pin = 1 << ('0' - '0');
unsigned int timer_prev = 1;
system_timer = 100;
CPU_PRESCALE(0x00); // 16 MHz
usb_init();
while (!usb_configured()) /* wait */ ;
_delay_ms(1000);
CPU_PRESCALE(0x04); // 1 MHz
TCCR1B |= (1 << CS10); // Set timer1 to 1 microsecond steps
TIMSK1 |= (1 << TOIE1); // enabled timer overflow interrupt;
sei();
while (1) {
if (system_timer != timer_prev) {
timer_prev++;
// send_int((int)system_timer);
usb_serial_putchar('\n');
continue;
}
}
}
ISR(TIMER1_OVF_vect)
{
system_timer++;
}
// Send a string to the USB serial port. The string must be in
// flash memory, using PSTR
//
void send_str(const char *s)
{
char c;
while (1) {
c = pgm_read_byte(s++);
if (!c) break;
usb_serial_putchar(c);
}
}
/* Write a decimal integer to the serial port
*/
void send_int(unsigned int val)
{
char c_out[10];
int ptr;
c_out[ptr++] = '\0';
if (val < 0) {
c_out[ptr++] = '-';
val = -val;
}
while (val > 0) {
c_out[ptr++] = (val % 10) + '0';
val /= 10;
}
ptr--;
while (ptr) {
usb_serial_putchar(c_out[ptr--]);
}
}
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