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[on:]

Hello,

Hello,

I am new to this forum and signed up because I have some questions on the HC-SR04 sonar sensors and the connection of multiple HC-SR04 to one board.

I am working on bin level sensing with the HC-SR04 on a 2560 board.

All works well with one sensor. Now my question: I need up to 22 HC-SR04 sensors to monitor my storage bin fill level.

Can I run multiple HC-SR04 sensors on one board?

The sensing time only needs to be every 5 minutes. Is it possible to have multiple sensors on the same wires?

Does each sensor have its one identity?

Next step would be to change the numerical info into a graphical form.

Thank you for any help.

Biermann

[Reply #1 on:]

Do need to use sonar sensors or can you just you IR sensors? 22, why so many?
That many sensors will require either a shift register(s) or an arduino mega. And even then you won't be able to run all the sensors at once, so your probably better off using 1 or 2 and point the sensor into the bin. If you point the sensor inwards, you can take a reading of how close the objects are to the sensor.
Empty bin = larger number
Full bin = very small number.

[Reply #2 on:]

How far apart are they? I'd be a bit worried about long cable runs picking up noise.

You might decentralize a bit by having groups of (say) 10 sensors hooked up to an Arduino, and using serial comms to send the results to somewhere else.

[Reply #3 on:]

Hello Nick @ HazardsMind,

Thank you for your replies.

We have about 22 grain bins were I would like to do a level sensing, 8 bins are within 40' of each other, 14 are in a cluster about 150' from the plc control system.

My thought was to read each bin perhaps only once every 2 or 3 minutes (i don't know if it is possible to increase sensing time when the reading changes) and have the board go to call each sensor for data?

Is this possible, who can write a program to do this? I am willing to pay!

Best regards,

Joerg

[Reply #4 on:]

Why is this thread locked?

150 feet is a long way for logic level signals. I suggest maybe radio-based system using Xbee or similar.

I'll move this thread to Gigs and Collaborations, since you seem to want to pay. And I'll unlock it.

[Reply #5 on:]

These sonar sensors don't use a serial protocol or any kind of addressing. Just a high pulse on one pin and a return pulse on the other. If you want to use multiples, you'll need a pair of pins for each sensor, or a driver board for each sensor that will let you use a serial protocol.

[Reply #6 on:]

Okay Carl,

This clears my head of one possibility, but gives two others.

At the moment, echo and trigger go to 12 & 13, can I use other locations on the board, too? That way I would have more sensors on the same board.

Can I than ask in long intervals for the input from 12 & 13, 10 seconds later 14 & 15, and so on?

You see, I have not much knowledge of this stuff, probably the reason I ask thus questions, otherwise I would just do it.

Thanks, Joerg