/*This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/.*/
// OCR2 values for available Transmit frequencies: OCR2A/B = 8000/Ft[Khz] - 1
#define F_8MHZ 0
#define F_4MHZ 1
#define F_2666 2
#define F_2000 3
#define F_1600 4
#define F_1333 5
#define F_1143 6
#define F_1000 7
#define F_880 8
#define F_800 9
#define F_727 10
#define F_666 11
#define F_615 12
#define F_571 13
#define F_533 14
#define F_500 15
#define FRQ F_1600 //Replace OCR2 value for frequency here, if necessary
#define ANTENNA_1 PD3 //Arduino Nano/Uno Pin D3
#define ANTENNA_2 PB3 //Arduino Nano/Uno Pin D11
void setup() {
//Timer 2: Carrier Frequency generation
TCCR2A = bit(COM2A0) + bit(COM2B0); // Toggle OC0A (Pin 11) and OC0B (Pin 3) on Compare Match
bitSet(TCCR2A, WGM21); // CTC Mode
TCCR2B = bit(CS20); // No clock Prescaling
OCR2A = FRQ;
OCR2B = FRQ;
bitSet(TCCR2B, FOC2B); // Force Output Compare B; Toggle inverted
//Timer 1: PWM
pinMode(9, OUTPUT);
TCCR1A = bit(WGM11) + bit(WGM10); //Fast PWM, 10 Bit
TCCR1B = bit(WGM12) + bit(CS10); // No Prescaling
TIMSK1 = bit(OCIE1A) + bit(TOIE1);// Output Compare A Match and overflow Interrupt Enable
//TCCR1A += bit(COM1A0) + bit(COM1A1); //Toggle Pin 9 on compare match
//ADC Settings
ADMUX = bit(REFS1) + bit(REFS0); //Reference internal 1.1V
ADCSRA = bit(ADEN) + bit(ADSC) + bit(ADATE); //Auto Trigger enable, free running
ADCSRA += bit(ADPS2) + bit(ADPS1); //Divide by 64 -> 18.5k Sample rate
DIDR0 = bit(ADC0D);
}
/* Overflow Interrupt*/
ISR(TIMER1_OVF_vect) {
uint16_t adc = ADC;
OCR1A = adc;
bitSet(DDRD, ANTENNA_1); // timer 2 outputs on
bitSet(DDRB, ANTENNA_2);
}
/* Output Compare A Match Interrupt */
ISR(TIMER1_COMPA_vect) {
bitClear(DDRD, ANTENNA_1); // timer 2 outputs off
bitClear(DDRB, ANTENNA_2);
}
void loop()
{
}