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| Riadok 1: |
Riadok 1: |
| Tento program pouzije PortD.4 (arduino D4) ako pocitadlo.
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| Mozne pripojit tlacitko, alebo 555 a pocitat pocet impulzov.
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| Vstavany terminal Arduina nema formatovanie, takze treba pouzit
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| iny terminal aby sa to pekne vypisovalo:
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|
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| <source lang="c">
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| #define SWITCH 5 // select the pin for Switch
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|
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| void setup()
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| {
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| pinMode(SWITCH, INPUT); // this pin is an INPUT
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| TCNT1 = 0x00; // initialize (CLEAR)counter
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| TCCR1B = 0x07; // T1 clk = external clock source on pin T1, rising edge
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|
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| Serial.begin(9600);
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| Serial.println("Button test:");
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| }
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|
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| void loop() // endless loop
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| {
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| Serial.print("Input D5 = ");
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| Serial.print(digitalRead(SWITCH),BIN);
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| Serial.print(" TCNT1 = ");
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| Serial.print(TCNT1,DEC);
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| Serial.print('\r'); // this will not work with embedded Serial Monitor,
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| // but works fine with e.g. putty terminal
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|
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| delay(250); // wait 1/4s for another measurement
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| }
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|
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| </source>
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|
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| [[Obrázok:AVR Timer T1 Counter.png|center]]
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| [[Obrázok:AVR Timer TCNT1 Counter.png|center]]
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|
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|
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| Nasledovny kus programu nastavi pocitadlo na 5 impulzov pred pretecenim (0xFFFF - 5) a
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| potom sleduje v hlavnej slucke, kedy nastane pretecenie. Ako hodinky je pouzity externy
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| signal na T1, cize tlacitko alebo 555.
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|
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| <source lang="C">
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| /* Example 9.2. Timer counter 1 in timer mode - pooled version */
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|
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| #define SWITCH 5 // Arduino D5, ATmega328 PD.5
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| #define LED 13 // Arduino D13, ATmega328 PB.5
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|
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| int ledState = LOW; // variable used to store the last LED status, to toggle the light
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|
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| void setup() // run once, when the sketch starts
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| {
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| /* *********************** Init device ************************************ */
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|
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| pinMode(SWITCH, INPUT); // this pin is an INPUT
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| pinMode(LED, OUTPUT);
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|
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| Serial.begin(9600);
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| Serial.println("Timer T1 test:");
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|
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| TCCR1B = 0x07; // T1 clk = external clock source on pin T1, rising edge
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| TCCR1A = 0x00; // T1 in timer mode
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| TCNT1 = 0xFFFB; // initialize the counter (16-bit! Low+High bytes)
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| TIFR1 = 0x01; // (1<<TOV1); if a 1 is written to a TOV1 bit
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| // - the TOV1 bit will be cleared
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| }
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|
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| /* *********************** Main Loop ************************************** */
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|
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| void loop() // run over and over again
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| {
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| if ( (TIFR1 & 0x01) == 0x01) // If the overflow flag is set
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| {
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| ledState = !ledState; // toggle the status of the ledPin
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| digitalWrite(LED, ledState); // update the LED pin itself
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| TCNT1 = 0xFFFB; // Restart T1 - reload
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| TIFR1 = 0x01; // Clear the overflow flag
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| }
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| else
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| asm("nop"); // Do nothing
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|
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| Serial.print("Input D5 = ");
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| Serial.print(digitalRead(SWITCH),BIN);
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| Serial.print(" TCNT1 = ");
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| Serial.print(TCNT1,DEC);
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| Serial.print('\r'); // this will not work with embedded Serial Monitor,
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| // but works fine with e.g. putty terminal
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|
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| }
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|
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| </source>
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