Generate single pulse from timer 1 in arduino nano

Question

i have a code that shot a single pulse from pin D5 timer 0 (based on josh levine code), it works fine. the code is below

#define OSP_SET_WIDTH(cycles) (OCR0B = 0xff-(cycles-1))
void osp_setup(uint8_t cycles) {
 TCCR0B = 0;
 TCNT0 = 0x00;
 OCR0A = 0;
 OSP_SET_WIDTH(cycles);
 TCCR0A = _BV(COM0B0) | _BV(COM0B1) | _BV(WGM00) | _BV(WGM01);
 TCCR0B = _BV(WGM02) | _BV(CS00);
 DDRD |= _BV(5);
}
void osp_setup() {
 osp_setup(1);
}
#define OSP_FIRE() (TCNT0 = OCR0B - 1)
#define OSP_INPROGRESS() (TCNT0>0)
#define OSP_SET_AND_FIRE(cycles) {uint8_t m=0xff-(cycles-1); OCR0B=m;TCNT0 =m-1;}
void setup()
{
 osp_setup();
}
void loop()
{
 OSP_SET_AND_FIRE(4);
 delayMicroseconds(20); 
}

however, i want to generate the same pulse in pin 10 or 9 which is timer 1, so a change the code a bit just like this

#define OSP_SET_WIDTH(cycles) (OCR1B = 0xff-(cycles-1))
void osp_setup(uint8_t cycles) {
 TCCR1B = 0;
 TCNT1 = 0x00;
 OCR1A = 0;
 OSP_SET_WIDTH(cycles);
 TCCR1A = _BV(COM1B0) | _BV(COM1B1) | _BV(WGM10) | _BV(WGM11);
 TCCR1B = _BV(WGM12) | _BV(CS10);
 DDRD |= _BV(10);
}
void osp_setup() {
 osp_setup(1);
}
#define OSP_FIRE() (TCNT1 = OCR1B - 1)
#define OSP_INPROGRESS() (TCNT1>0)
#define OSP_SET_AND_FIRE(cycles) {uint8_t m=0xff-(cycles-1); OCR1B=m;TCNT1 =m-1;}
void setup()
{
 osp_setup();
}
void loop()
{
 OSP_SET_AND_FIRE(4);
 delayMicroseconds(20); 
}

but it doesn't work, and i am stuck, any help? i use arduino nano

Thank you

• jsotola: what does this mean? ... it doesn't work
• Gerben: Did you just change the 0s with 1s? You can’t do that as the registers for timer1 are a bit different from timer 0. Check the datasheet to see what the original code does. The look in the datasheet and see which bits need to be set in which registers to get the same functionality.
• Zahi Azmi: @jsotola it didn't generate the desired signal
• Zahi Azmi: @Gerben that is because when i change the 0s with 2 and use pin D3, it works fine
• jsotola: @ZahiAzmi, it didn't generate the desired signal that is almost the same as it doesn't work .... what did it generate?

Answer 1

Timer1 has a few extra features, so you need to set the registers slightly differently from timer0 (or timer2). You need to also set the WGM13 bit in the TCCR1B register.

Since timer1 is a 16 bit timer, you need to change OSP_SET_AND_FIRE to also use 16 bits.

Lastly; Arduino pin 10 is port B, not port D.

#define OSP_SET_WIDTH(cycles) (OCR1B = 0xff-(cycles-1))
void osp_setup(uint8_t cycles) {
 TCCR1A = 0;
 TCCR1B = 0;
 TCNT1 = 0x00;
 OCR1A = 0;
 OSP_SET_WIDTH(cycles);
 TCCR1A = _BV(COM1B0) | _BV(COM1B1) | _BV(WGM10) | _BV(WGM11);
 TCCR1B = _BV(WGM12) | _BV(WGM13) | _BV(CS10);
 DDRB |= _BV(DDB2);//pin 10; PB2
}
void osp_setup() {
 osp_setup(1);
}
#define OSP_FIRE() (TCNT1 = OCR1B - 1)
#define OSP_INPROGRESS() (TCNT1>0)
#define OSP_SET_AND_FIRE(cycles) {uint16_t m=0xffff-(cycles-1); OCR1B=m;TCNT1 =m-1;}
void setup()
{
 osp_setup();
}
void loop()
{
 OSP_SET_AND_FIRE(4);
 delayMicroseconds(20); 
}