Object detector using ultrasonic sensor with 555 timer

[engnrshyckh]

TL;DR Summary

I am doing a simple project in which i want to detect object using 555 timer and ultrasonic sensor.

See the attached figure.
I used 220uF with buzzer and also tried 10uF capacitor but buzzer isn't loud enough. I don't have any 3.3pf capacitor. I used 1.1 pF instead. I also tried changing the resistance of potentiometer but still buzzer isn't sound loud enough.

 

[Baluncore]

The 3.3 pF capacitor is much too small for a 555 oscillator.
frequency = 1.46 / ( (R1 + 2*R2) * C )
C = 1.46 / ( 5kHz * ( 10k + 2*1k) ) = 24 nF

 

[engnrshyckh]

The 3.3 pF capacitor is much too small for a 555 oscillator.
frequency = 1.46 / ( (R1 + 2*R2) * C )
C = 1.46 / ( 5kHz * ( 10k + 2*1k) ) = 24 nF

I don't have such values of capacitance can i change the value of R2 FOR fixed value of C i. I 3.3pF

 

[Baluncore]

I don't have such values of capacitance can i change the value of R2 FOR fixed value of C i. I 3.3pF

I have no idea what you are suggesting there.

If I remember correctly, the 555 needs a timing capacitor of 470pF minimum.
The 3.3pF is not useful anywhere in the circuit. I do not know why the website showed that value on the schematic. If you look in the parts list, you will see it specifies a 3.3nF capacitor. That is a better choice.

I computed a timing capacitor value of about 24nF. The closest available value will probably be 22nF. Try any value of capacitance you can find between (1nF = 0.001uF) and (100nF = 0.1uF).

https://en.wikipedia.org/wiki/555_timer_IC#Astable

 

[Windadct]

Asside from the 555 issues - the sensor in your image looks like a Ultrasonic DISTANCE sensor -

https://www.sparkfun.com/products/15569

This needs more then a timer.

 

[Baluncore]

- the sensor in your image looks like a Ultrasonic DISTANCE sensor -

If there is no reflector within range in the 15° beam, then it does not produce a detection pulse, so it may be used as a detector without range.

 

[engnrshyckh]

Asside from the 555 issues - the sensor in your image looks like a Ultrasonic DISTANCE sensor -

https://www.sparkfun.com/products/15569

This needs more then a timer.

Yes it is so may be a commarotor will work

 

[Tom.G]

Yes, a comparator will likely work.

Although likely needed only for the maximum range of 4 meters, please note the comment on page 3 of the datasheet:
(bold added)

When tested objects, the range of area is not less than 0.5 square meters and the plane requests as smooth as possible, otherwise, it will affect the
results of measuring.

Cheers,
Tom