34 lines
1.1 KiB
C
34 lines
1.1 KiB
C
// Slow-scope. A free-running AVR / ADC "oscilloscope"
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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 "pinDefines.h"
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#include "USART.h"
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#define SAMPLE_DELAY 20 /* ms, controls the scroll-speed of the scope */
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// -------- Functions --------- //
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static inline void initFreerunningADC(void) {
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ADMUX |= (1 << REFS0); /* reference voltage on AVCC */
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ADCSRA |= (1 << ADPS1) | (1 << ADPS0); /* ADC clock prescaler /8 */
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ADMUX |= (1 << ADLAR); /* left-adjust result, return only 8 bits */
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ADCSRA |= (1 << ADEN); /* enable ADC */
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ADCSRA |= (1 << ADATE); /* auto-trigger enable */
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ADCSRA |= (1 << ADSC); /* start first conversion */
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}
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int main(void) {
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// -------- Inits --------- //
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initUSART();
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initFreerunningADC();
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// ------ Event loop ------ //
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while (1) {
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transmitByte(ADCH); /* transmit the high byte, left-adjusted */
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_delay_ms(SAMPLE_DELAY);
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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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