Which pin on the 555 timer IC is the timer pin?

555 Timer Pinout

Pin Number	Pin Name
1	Ground
2	Trigger
3	Output
4	Reset

What are the pins of a 555 timer?

The 555 timer IC consist of 8-pins where each pin has some function. The pin configuration of this IC is shown below. Pin-1 is a GND pin which is used to supply a zero voltage to the IC. Pin-2 is a trigger pin which is used to convert the FF from set to RST (reset).

What is pin 4 on a 555 timer?

)\n \n Reset: Pin 4 is the reset pin, which can be used to restart the 555’s timing operation. Like the trigger input, reset is an active low input. Thus, pin 4 must be connected to the supply voltage for the 555 timer to operate.

What is the name of pin 8 in 555 timer?

Pin	Name	Description
6	threshold	Detects when the voltage on the timing capacitor rises above 0.66 Vcc and resets the output when this happens.
7	discharge	Provides a discharge path from the timing capacitor to ground when the output is low.
8	Vcc	Positive power supply voltage.

Can you use pin 13 on Arduino?

You could use pin 13 as an input of you desolder the LED connected to that pin. You should also be able to use pin 1 as an input, but you may have to disconnect the phototransistor (or at least keep it in the dark) when uploading sketches.

What does digitalWrite mean in Arduino?

The digitalWrite() function is used to write a HIGH or a LOW value to a digital pin. If the pin has been configured as an OUTPUT with pinMode(), its voltage will be set to the corresponding value: 5V (or 3.3V on 3.3V boards) for HIGH, 0V (ground) for LOW.

Is XTAL1 connected to XTAL2?

A Quartz Crystal Oscillator is connected across XTAL1 and XTAL2 pins i.e. Pins 19 and 18. The capacitors C1 and C2 can be selected in the range of 20pF to 40pF.