Turning on circuit if ultrasonic sensor detects an object

Hi there, I am developing a project with 2 stepper motors and 4 sensors including ultrasonic sensor. When ultrasonic sensor detects an object I want my circuit to be turned on and it should be off all other time without consuming energy. Please help me by telling how can I proceed.

Please help me by telling how can I proceed.

One of 2 ways: Use the examples on this web site, in the Arduino IDE and on the internet to learn the basics of coding. Then divide your project in to small steps and get each one working separately before combining them in to the larger project. Come here for help when you get stuck and make sure you follow the forum instructions to get helpful answers: General guidance And How to use this forum

Or, if you don't want to do that, click on 'report to moderator' and ask them to move this to 'gigs and collaborations' and ask someone to do your project for you, you will need to give some idea of how much you are willing to pay.

OK, the point here is that the Arduino is part of the ultrasonic rangefinder, so it will be operating - and drawing power - in order to determine whether the rest of your system is enabled.

To reduce the power draw somewhat in the rangefinder, you need to determine how often it is necessary to detect the presence of an object and to turn on the Arduino and rangefinder at that regular interval and if no object is detected, to put it to "sleep" until the next check.

An ultrasound sensor can not make measurements without using any power.

A sensor can not normally control any outside circuits by itself; it relies on a microcontroller of sorts to do just that. Most MCUs can go in deep sleep mode using very little power, but they still do consume some.

Yep can’t think of any way of running sensors without consuming power.

Ultrasonics - needs power IR - needs power laser rangefinder - needs power Capacitive - needs power

How about a trip line that activates a switch?

wolframore: Yep can’t think of any way of running sensors without consuming power.

The Thing comes close...

Nice find, even that needs an “illuminating” radiation to power it... invented by Thermamin... haha he had some interesting ideas about heterodyne.

Some problems with that Wikipedia article. It refers to picking up harmonics of the illuminating frequency but “The Thing” (unlike later variants) had no non-linear element to generate harmonics. :astonished:

I read it as antenna picked up the frequency and modulated a capacitive pickup and then transmitted at a harmonic of the illuminating frequency (using the cavity resonator).