[SOLVED] Reading Serial from a Breadboard 'Arduino' with an Uno

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1

Good afternoon,

Sorry if this is a re-post, I couldn't find a relevant post. I currently have an arduino running on a breadboard, and am satisfied with the code but would like to be able to see the serial output. I know I can get a breakout board to allow me to read and program the board with usb. My question is: is there any way to read the serial output of my project using an Uno which is connected to a PC?

I don't want to hook the Uno up into my circuit but want to be able to monitor the serial output. Is there anyway to have the Uno read a pin on the breadboard?

Sorry if this is confusing, and thanks in advance for the help.
Hainsy

2

Hainsy:
Good afternoon,

Sorry if this is a re-post, I couldn't find a relevant post. I currently have an arduino running on a breadboard, and am satisfied with the code but would like to be able to see the serial output. I know I can get a breakout board to allow me to read and program the board with usb. My question is: is there any way to read the serial output of my project using an Uno which is connected to a PC?

I don't want to hook the Uno up into my circuit but want to be able to monitor the serial output. Is there anyway to have the Uno read a pin on the breadboard?

Sorry if this is confusing, and thanks in advance for the help.
Hainsy

Sure there is. On the Uno place a jumper wire between reset and a ground pin (this will keep the Uno's 328P chip inactive). Then wire the serial output pin from your breadboard chip to Uno's pin 1 and also a wire from the serial input pin from your breadboard chip to Uno's pin 0. Finally you will need a ground wire between the Uno and your breadboard's ground.

Lefty

3

Thanks Lefty,

Complete dummy questions: which are the serial input and output pins?
Less of a dummy question (I hope): If I removed the atmega chip completely would this still work or does the signal go through the microcontroller?

Thanks again!

4

The tx/rx pins are pin 3 and pin 2, take a look at this:

If I removed the atmega chip completely would this still work

Yes it will still work (although personaly I think the other solution is easyer)

It is also a good idea to connect small resistors in series with the rx/tx ines from your standalone to the Arduino (330-1000 ohm)

5

Thanks! You guys just saved me a headache.

6

I don't know if anyone will see this, since I marked it as solved, but will connecting to the serial in and out ports also allow me to flash the Atmega with scripts from the PC based IDE? I didn't realize this was possible and have been pulling the chip from my breadboard and putting the chip into my Uno to program it (quite annoying considering all the revisions I've been doing). :stuck_out_tongue:

It's amazing the things you can learn when you ask a simple question...

7

If your Atmega on the breadboard has a bootloader, you can upload sketches through the serial lines.
But you have to make a manual reset, when uploading.

Another possibility is to use your Arduino as ISP

Nick Gammon has a tutorial: