Can one computer operate two Arduino Uno?

Using Arduino IDE 1.x
1

I want to make a CNC router so is it necessary to get another computer for operating Arduino Uno or can I use same computer which I already use to run my first Arduino based CNC router. is it possible. If yes, please tell me how can I do that

2

Dropside:
can I use same computer which I already use to run my first Arduino based CNC router.

Almost certainly, yes.

Dropside:
please tell me how can I do that

We'd probably need more information to give any specific advice on this. My guess is the CNC software on your computer that sends the G-code is using the serial port of your Uno for communication. When you plug multiple Unos into your computer, each will get its own serial port. So you just need to select the correct serial port in the CNC software for each Uno.

3

The complication is that if you want to use the IDE with two Arduinos then if you have only one instance of it running then if you do file/new or open an existing program then all of the programs using the single IDE instance will use the same COM port. Change the port in one and they all change

The way round this is to open two (or more) instances of the IDE then each can use a different COM port

4

So that means there is no problem to do that???

5

Dropside:
So that means there is no problem to do that???

If that question refers to reply #2, then there is no problem having two instances of the IDE open at the same time, each with an Arduino with a different COM port

6

Dropside:
So that means there is no problem to do that???

Yup, lots of us do it all the time.

As far as the computer itself is concerned, an Arduino (with some exceptions for less common boards) just looks like a serial port, and you can have as many of those connected as you want and have USB ports/hubs to connect them to.

I think my personal record is like 5-6 serial ports, 3 of them for an Arduino itself, and the others connected to one of those devices, but not to the port used for programming.

As UKHeliBob noted, if you have multiple sketches open with one "instance", they will all share the same board/port/etc options. If you open a second "instance" (by opening Arduino again, while it is already running), that will be a second "instance" and will not share settings with the first. Note that it is not particularly clear which windows are associated with what instance. Whenever the last window associated with an instance is closed, any changes made to preferences, as well as currently open sketch, will be saved. But these caveats are generally nuisances at worst.

7

Over 14 live boards here and up to 3 CNC machines too, so I can give this a most definite YES.

Bob.

8

Thank you 2 all

9

Step 1: Basic Connections. First, you have to connect both Arduinos to each other. ...
Step 2: Add LED to the Secondary Arduino. Connect one of the Arduinos to a breadboard and connect an LED to that breadboard. ...
Step 3: Adding the Potentiometer. ...
Step 4: Master Arduino Code. ...
Step 5: Slave Arduino Code. ...
2 Discussions.
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10

henuzm:
Step 1: Basic Connections. First, you have to connect both Arduinos to each other. ...

I don't think that that is what OP asked for. I think that the question is about using on PC to operate the CNC and at the same time do programming or use a second Arduino for other purposes on the same PC.