# Maximum and minimum voltage for sensor?

Hello everyone
i have an ultrasonic sensor HCSR-04 ,
i read that it operate on 5v for 'vcc' pin put i don't know how much voltage need for the trigger pin !, however , i was working on Arduino UNO using digital pins which it is ~5v if this pins is 'HIGH'.
my question is :
if i want to use PWM pins and apply analogWirte(100) ,does the ultrasonic will operate same if i am using digital pin that goes only HIGH or LOW ? ?

if i want to use PWM pins and apply analogWirte(100) ,does the ultrasonic will operate same if i am using digital pin that goes only HIGH or LOW ?

It makes no sense to use PWM to operate an ultrasonic distance sensor.
You might be confused by the term analogWrite(). The output is not an analog signal but a PWM signal. So the voltage will always be 5V (on the UNO), itâ€™s just turned on and off for different periods of time in a fast repetition.

You might be right ,it make no sense but i run into a situation that the I/O pins provide only2.3v?

TheNoneP:
You might be right ,it make no sense but i run into a situation that the I/O pins provide only2.3v?

An average voltage (which a multimeter is going to read) of about 2.3V is what you'd expect to see from an analogWrite(100). The pin will be high (5V) a bit less than half the time and low (0V) for the rest.

Steve

So PWM will not modify the voltage value ?
What is the voltage required for trigger pin in ultrasonic?

The data sheet for the devices shows:

"(1) Using IO trigger for at least 10us high level signal,".

High level means 5 volts in this case.

Paul

You might be right ,it make no sense but i run into a situation that the I/O pins provide only2.3v?

Which I/O pins? Are you trying to replace another board by an Arduino? What are you trying to achieve?

What is the voltage required for trigger pin in ultrasonic?

That depends on the board used, in your case it's 5V as Paul_KD7HB already mentioned.