Raspberry Pi / Arduino question

[Mike1983]

Hello

Not sure if this is the correct forum, sorry if not...

I've got a project in mind but haven't a clue where to start researching. I was basically wondering if the below is possible using a PI, Arduino or other "device"

1) receive a voltage input from a relay contact
2) energise an "output" relay when the above input is received
3) connect to an IP network with other PIs / Arduino / other "devices" doing the same job in another location but on the same network.
4) an input received on "device" 1 could also trigger an output on other "devices" on the network

So can this be do done? If so, what's the most efficient solution and how difficult would this be to learn myself? I'm tech savvy, electrically minded etc.

Thank you for your time.

Mike

 

[touch]

Yes, a Pi or Arduino could do that. It would be massively overkill though - it could probably be done with a simple electronic circuit (using a wire to pass a voltage signal between nodes rather than an IP network

 

[Mike1983]

Excellent, thanks. So out of a PI or Arduino, which would you recommend and do you have a pointer as to a good starting place for research / forums etc?

And yes, you're right, this could be done using cables however the expense / hassle involved in running them would cost too much. Part of the potential cable run would go outdoors so would need ground excavation hence my preference to use an IP network to link the "devices" / nodes / zones. The IP network already exists in all areas btw.

Plus a little part of this is me wanting to try / learn something new.

Thank you

Mike

 

[touch]

Fair enough. In that case i'd go for a Pi. It has network connectivity out of the box whereas you need extra parts to do that with an arduino.

The Raspberry Pi website has tonnes of info and a good support forum too.

 

[m3csl2004]

Bare in mind, you will likely need to opto-isloate/buffer the I/O on either the Arduino or RPi to protect the board from the relay. RPi is 3.3v logic with low current limits, and I think Arduinos are 5v or 3.3v dependent upon model. This applies to the input and output.

A BeagleBone Black would also do this job easily.

 

[Mike1983]

Thanks for your responses. I shall be going with an RPi solution.

Can't find anywhere that immediately describes how to get RPi 1 triggering an output on RPi 2 but I'm going to look at the RPi website and forum. Looking forward to figuring this out.

Thanks again

Mike

 

[visibleman]

Can't find anywhere that immediately describes how to get RPi 1 triggering an output on RPi 2.....

Look at GPIO and TCP client server type code examples; plenty around, especially for Python.

 

[K1LaW8tt5]

If i have read what you are trying to do correct I would try to use an arduino with ethernet/wireless shield at each location(monitoring Your input) and one central pi as the brains monitoring the input status and controlling the output at each arduino on the network.
You could do it all with pi's but they depend on os and sd card to run code( i could be wrong with that)
On top of the raspberry pi website there is the arduino forums and also instructables have a good database of projects and you may find some similar for ideas and help.

The arduino is very easy to get started on. You can download the software to your pc and check out some of the sample code. There is also a lot of libraries available to make things easier.

Best of luck with the project

 

[visibleman]

.....with ethernet/wireless shield...

The Ethernet shield for an Arduino alone is about the cost of a RPi so using Ardunio's will be a more costly solution.

Plus it might be a little easier to pick up Python (or a similar high-level language) than C but there's more than one way to skin a cat on this project, so it comes down to preference.

 

[K1LaW8tt5]

The Ethernet shield for an Arduino alone is about the cost of a RPi so using Ardunio's will be a more costly solution.

Plus it might be a little easier to pick up Python (or a similar high-level language) than C but there's more than one way to skin a cat on this project, so it comes down to preference.

If you buy the official one yes but you can get different ones made to the exact same spec for a lot less. An uno with ethernet shield can be got for about £20-25.

 

[touch]

If you buy the official one yes but you can get different ones made to the exact same spec for a lot less. An uno with ethernet shield can be got for about £20-25.

Yep, an arduino could be done for a lot less.
An Attiny85 chip + ESP8266 wifi module could be built for <£5 per node.

I still think the raspberry pi is a better solution for a beginner though. It handles all of the ethernet traffic, etc so all you need to worry about is getting the input/output working. It's much easier to debug on a "real" computer like the Pi as you can wire it up to a monitor and see whats going on in a way that will be more familiar. Using a serial terminal with an Arduino is just adding more confusion.

Having said that, the OP did say he wants to use this as an excuse to learn something new, so maybe the Arduino might appeal to him?

 

[Makhaira]

I think the computing aspect has been thoroughly covered above, the other thing to account for is making sure you pick a suitable relay and protection for hooking it up to the RPi.

Have fun!