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Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 1:46 pm
by Keith Baxter
Advise please.

If i have 3 x Raspberry Pi running 3 separate monitors. How do I connect multiple Arduinos to each Pi ? Will using USB splitters work .

This is the configuration.
RPi _1 is running the the 17' NextGen instrument. this is not a touch screen monitor.
RPi_2 is running a 10.1" touch screen. This is going to to show the Caution Warning Advisory Panel and act as a keyboard to the FMS running on the RPi_1. So the input from the keyboard on RPi_2 needs to be connected/read by RPi_1 and RPi_3.
RPi_3 is running a 14" touch screen. This is going to be the MDU unit.

Arduino_1 is going to run the hardware for RPi_1 but also needs to talk to RPi_2 & RPi_3
Arduino_2 is going to run the hardware for RPi_3 but also needs to talk to RPi_1 & RPi_2
Other Arduinos may need to talk directly to all the other RPi's

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 2:10 pm
by Corjan
You are really going all the way :)

USB splitters should work.

Arduino's can only talk to the Raspberry Pi they are connected to.

You can however communicate between instruments (running anywhere, PC, Pi etc.) with the following functions:
https://siminnovations.com/wiki/index.p ... munication


Corjan

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 2:15 pm
by Keith Baxter
Yes Corjan I want to do it the best I can. ;)

So you can see why my head is spinning. I don't want to create a instrument only to find I have to start from the beginning again.

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 3:25 pm
by Keith Baxter
Corjan,

Can I plug all the Arduino's into ONE powered USB splitter, then daisy chain the Raspberry Pi's together with USB cables?

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 5:58 pm
by Ralph
You can't connect Raspberry Pi's together through USB, but maybe you meant something else? You can connect multiple Arduino's to one Pi, but you would indeed need a powered USB hub.

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 7:11 pm
by Keith Baxter
Ralph wrote: Mon Apr 09, 2018 5:58 pm You can't connect Raspberry Pi's together through USB, but maybe you meant something else? You can connect multiple Arduino's to one Pi, but you would indeed need a powered USB hub.
Ralph,Perhaps I was unclear in my question. I did understand what Corjan said about inter instrument communication between the Raspberry Pi's.
I want to limit the number of cables and USB splitters.

SO this would be first prize
1) I want to connect up multiple Arduinos ( three or four) to one USB splitter. So that is one splitter and three USB cables.
2) Then I want to connect the splitter to one Raspberry Pi That is another USB cable.
3) Then I want to connect the three Raspberry Pi's together using two USB cables. This way the arduinos are connected to the other two Raspberry Pi's

I am hoping that this will work in connecting the arduinos to all the Raspberry Pi. If not then I would have to get another splitter and extra cables.

I just dont want to destroy Arduinos and Raspberry Pi's

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 7:59 pm
by Keith Baxter
Ralph, I think I found the answer.

"The RPi 3B uses a LAN9514 Chipset on the Single USB Bus to provide 4 x USB."

I did not know if the Pi used one or many buses. So i guess daisy chaining the RPi's will work.

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 8:14 pm
by Ralph
You can connect them to each individual RPi USB port, but I'm not sure if the RPi can deliver enough power to support all your Arduino's. It depends on how much output stuff you've connected to the Arduino's. With a decent power supply it should be 500mA per port.

You cannot connect an Arduino to multiple RPi's. If you want button presses to reach other RPi's then you'll need to use 'inter-instrument-communication', which goes through the flight simulator plugin. Or connect an Arduino to each RPi.

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Mon Apr 09, 2018 8:23 pm
by Keith Baxter
Ralph,

Thank you for clearing that up. Then the splitter idea is a waist of time in my case.

I will just connect the Arduino to the Pi it works mostly on and do inter communication on the other parts.

Or are you telling me that I should connect the arduinos to the PC USB and and use inter communication on all Pi's?

Keith

Re: Multiple Arduinos connected to Multiple Raspberry Pi

Posted: Tue Apr 10, 2018 7:19 am
by Ralph
You can either connect them to a RPi or the PC, doesn't matter much if you're using inter-instrument-communication (let's call it IIC ;)) But if the logic happens on the RPi, I guess it would make more sense to connect them to the RPi.