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Topic: Ir sensors (Read 3478 times) previous topic - next topic

Grumpy_Mike

The way the parts are physically arranged has no bearing on the way they are electrically connected.

PaulRB

#16
Jun 18, 2017, 11:05 am Last Edit: Jun 18, 2017, 11:16 am by PaulRB
Question: you want the led to light when the ir sensor in that node senses an object? Is that the only mode of operating?

If so, perhaps no Arduino is needed. If you use suitable photo-transistors in place of photodiodes, or an ordinary transistor connected to the photodiode, perhaps they could drive the led directly. Each node would operate independently. The ir illuminators would be constantly on, so you would have to take physical measures to prevent nearby nodes from being triggered accidentally.

My suggestion would be to start small, since this is your first project. Get one node working on a breadboard. Then ask for advice on a multiplexing circuit (if that is even needed).

INTP

No Arduino necessary if it's a simple table that lights up under objects. But if you're going to build such a thing, might as well throw in an MCU so you can play patterns and animations. Ripples out from the object and other such fanciness.

But yeah, I'm assuming you saw this done on some Youtube vid or something, care to share which project you're imitating?

Kal22378

I have made a circuit on a breadboard without using a microcontroller. I am confused as how to make multiplexing work though. Any suggestions on code and literature to learn about multiplexing would be much appreciated. I like the idea of multiplexing as there would be less chips involved.

Kal22378

INTP..
I am unsure which youtube video I watched sorry.

Smajdalf

#20
Jun 26, 2017, 09:39 am Last Edit: Jun 26, 2017, 12:14 pm by Smajdalf
I am unsure which youtube video I watched sorry.
Hi thinks you saw somewhere something and want to create something similar. If you are able to show us existing thing you want to copy/make cheaper/better it would help us understand what you need and give you better advice. This way we can provide only very general help.

Try to look at Step 1 of this, it is nice explanation of multiplexing with pictures.

EDIT: fixed broken link
How to insert images: https://forum.arduino.cc/index.php?topic=519037.0

PaulRB

I have made a circuit on a breadboard without using a microcontroller.
Can you post a schematic for that? Hand drawn is ok, but please remember all the component codes and values.

PaulRB


Kal22378

https://youtu.be/fxkEPKGgv8o

This is the link to the video I seen.

Kal22378

This is what I am aiming for as far as design. Something along these lines.

Kal22378


INTP

So what is your problem?

Grumpy_Mike

Apart from the total lack of decoupling capacitors on those chips, I can't see what you are asking.

Smajdalf

https://youtu.be/fxkEPKGgv8o

This is the link to the video I seen.
I looks nice. But I am afraid it is quite complicated to make - you will need experience with soldering, electronics and probably woodcrafting. I think it will be better to start with something smaller. If you are very lucky you may be able to get it work somehow with good guidance but if anything go wrong you will have little chance to find what is wrong and how to fix it. Start with small project to prevent investing lot of effort into something that is impossible due to beginner mistakes in design. Try to make one node working (possibly following the video) and if you run into troubles ask here posting what you have done and what went wrong.
How to insert images: https://forum.arduino.cc/index.php?topic=519037.0

Kal22378

Not really if you look at the response time of your specific IR sensor.

However your idea of a matrix is a lot better than a bunch of shift registers. All though with a matrix for the display LEDs you would have to keep up the multiplex rate.

I recon the best bet is a multiplexed IR LED and IR sensor and use a WS2812b strip of LEDs for the visual display.
I have a question about multiplexing the sensors. Can you explain how I would go about doing that? I know I have columns and rows but i have +5v, Gnd, and output for the sensors. Thanks

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