Using a switch to "unplug" Arduino Uno

Other Hardware 3rd Party Boards
1

I want to use a switch to simulate unplugging and replugging an Arduino Uno USB connection. I read somewhere that a simple switch between two pins can do this, but I can't remember which two pins it is. Anyone know?

Thanks for the help.

2

Well, lets see. There are 4 pins in the connector. Two are for data, one is ground and one is + 5 volts. Do you really think it is a good idea to SHORT any of the 4 pins to another?
Paul

3

You could use a 3 pole switch, circuit wise it should work on a DC level but in the real world is it capable of the speeds and isolation the USB requires. You would not open the ground. Not opening the data lines will cause problems. This is definitely not recommended and it is possible to generate a transient that may damage your computer and or Arduino.

4

Hi, @videosonix

Why?

Tom... :smiley: :+1: :coffee: :australia:

5

I don't want to short anything. I thought there was a way to basically switch the arduino on/off. That's all.

6

Hi,
Is your project going to be permanently connected to a PC, or will you have a separate power supply for it?

What is your application?

Thanks.. Tom.. :smiley: :+1: :coffee: :australia:

7

I'm building a MIDI controller. If the Arduino is connected to the MIDI OUT while you are updating the program, it causes glitching and spurious noises.

And typing this answer out has actually given me the answer to my own question! I think I have to put the switch in-line with the MIDI out, not the USB. Doh! Should be easy now.

8

You can connect a switch between Reset and GND. That will pull down the reset pin, holding the microcontroller in its reset state. It won't do anything in that state. The board will of course still be powered.

Since it's not clear what you want to achieve, I can't tell if the above answers to your needs. So let's hear about those needs - if not, the answer will remain "yes, no, maybe".

9

I think that would do the job as well. Thanks.

10

This is what is called a "short".

11

Well in that case, I do want to create a short! Between the GND and Reset pin.

12

Reset will just reboot your Arduino, how is this helpful with upload noises?

13

Then you need a double pole switch to disconnect the MIDI circuits from the TX & RX connectors during upload of code.
This is what I used here :-
MIDI Shield

14

Hi Grumpy_Mike. Yes, this is exactly what I need. Thanks.

15

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