/* ATtiny85 IR Remote Control Receiver
David Johnson-Davies - www.technoblogy.com -
3rd April 2015
ATtiny85 @ 1 MHz (internal oscillator; BOD
disabled)
CC BY 4.0
Licensed under a Creative Commons Attribution
4.0 International license:
http://creativecommons.org/licenses/by/4.0/
http://www.technoblogy.com/show?V6F
*/
volatile int NextBit;
volatile unsigned long RecdData;
int Brightness;
// Demo routine
void ReceivedCode(boolean Repeat) {
// char buff[64];
// sprintf(buff,"%d,%x",Repeat,RecdData);
// mySerial.println(buff);
Serial.print(Repeat);
Serial.print(",");
Serial.println(RecdData,HEX);
}
// Interrupt service routine - called on every falling
edge of PB2
ISR(INT0_vect) {
int Time = TCNT0;
int Overflow = TIFR & 1<<TOV0;
// Keep looking for AGC pulse and gap
if (NextBit == 32) {
if ((Time >= 194) && (Time
<= 228) && (Overflow == 0)) {
RecdData = 0; NextBit = 0;
} else if ((Time >= 159) &&
(Time <= 193) && (Overflow == 0))
ReceivedCode(1);
// Data bit
} else {
if ((Time > 44) || (Overflow != 0))
NextBit = 32; // Invalid - restart
else {
if (Time > 26) RecdData
= RecdData | ((unsigned long) 1<<NextBit);
if (NextBit == 31)
ReceivedCode(0);
NextBit++;
}
}
TCNT0 =
0;
// Clear counter
TIFR = TIFR |
1<<TOV0; // Clear
overflow
GIFR = GIFR |
1<<INTF0; // Clear INT0 flag
}
// Setup **********************************************
void setup() {
// Set up Timer/Counter0 (assumes 1MHz clock)
TCCR0A =
0;
// No compare matches
TCCR0B =
3<<CS00;
// Prescaler /64
// Set up INT0 interrupt on PB2
MCUCR = MCUCR | 2<<ISC00; //
Interrupt on falling edge
GIMSK = GIMSK | 1<<INT0; //
Enable INT0
NextBit =
32;
// Wait for AGC start pulse
Serial.begin(9600);
Serial.println("ATtiny 85 IR Receive demo start");
}
void loop() {
} |
