Hi guys!
I have a project about designing and implementing a range finder without using microcontroller, pic etc. The range which will be determined by sensor should be between 10 and 99 cm. However, i am not sure which sensor is the best for this situation. Does anyone can help me to determine sensor type? such as infrared, ultrasonic etc. or a different method to measure range...

 

What is required precision of the measurement?

 

Part of the project, whether explicitly stated or not, is probably you spending some time learning about the various different options for sensing technology and weighing pros and cons against the project requirements and then making a decision.

 

maximum 5% error is acceptable

 

maximum 5% error is acceptable

Let me rephrase.

Do you want the measurement to be a whole number? Or do you want to have decimal places?

If you want decimal places. How many decimal places?




Additionally.
Is there size requirement?
Is there mass requirement?
Is there power requirement?

All these things will help you determine which sensor to use. For example, you might find some really nice sensor, but it is too large, if you use this sensor, you will not meet size requirement, therefore this particular sensor is not acceptable.

 

This thread describes a discrete logic timer for a pinewood derby racetrack. The timing starts when a car rolls through one sensor and stops when it rolls through a second sensor.

For sonar, replace the track sensor logic with something that starts the timer when the ping is sent and stops it when the echo is received, calibrate the count frequency to correspond to the speed of sound (147.5uS/inch in std. conditions IIRC) and there you are.

As the others have said, you have to make some decisions before proceeding but hopefully that discussion will provide a point of reference and an idea of the complexity involved in a discrete approach.

Have fun.

 

Just Google Ultrasonic Distance Circuit. There are designs out there that don't use MCUs.