69 lines
2.0 KiB
C
69 lines
2.0 KiB
C
/*
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Press the button as quickly as you can after the LEDs light up.
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Your time is printed out over the serial port.
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*/
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// ------- Preamble -------- //
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#include <avr/io.h>
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#include <util/delay.h>
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#include <avr/interrupt.h>
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#include "pinDefines.h"
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#include "USART.h"
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#include "support.h"
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static inline void initTimer1(void) {
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/* Normal mode (default), just counting */
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TCCR1B |= (1 << CS11) | (1 << CS10);
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/* Clock speed: 1 MHz / 64,
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each tick is 64 microseconds ~= 15.6 per ms */
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/* No special output modes */
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}
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int main(void) {
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uint16_t timerValue;
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// -------- Inits --------- //
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initUSART();
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initTimer1();
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LED_DDR = 0xff; /* all LEDs for output */
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BUTTON_PORT |= (1 << BUTTON); /* enable internal pull-up */
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printString("\r\nReaction Timer:\r\n");
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printString("---------------\r\n");
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printString("Press any key to start.\r\n");
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// ------ Event loop ------ //
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while (1) {
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receiveByte(); /* press any key */
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printString("\r\nGet ready...");
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randomDelay();
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printString("\r\nGo!\r\n");
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LED_PORT = 0xff; /* light LEDs */
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TCNT1 = 0; /* reset counter */
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if (bit_is_clear(BUTTON_PIN, BUTTON)) {
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/* Button pressed _exactly_ as LEDs light up. Suspicious. */
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printString("You're only cheating yourself.\r\n");
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}
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else {
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// Wait until button pressed, save timer value.
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loop_until_bit_is_clear(BUTTON_PIN, BUTTON);
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timerValue = TCNT1 >> 4;
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/* each tick is approx 1/16 milliseconds, so we bit-shift divide */
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printMilliseconds(timerValue);
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printComments(timerValue);
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}
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// Clear LEDs and start again.
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LED_PORT = 0x00;
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printString("Press any key to try again.\r\n");
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} /* End event loop */
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return 0; /* This line is never reached */
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}
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