is it posible to use Uno as serial-usb for another atmega328?

Development Tools IDE 1.x
1

Hello I am a newbie to arduino and electronics in general

I have a Nano clon that I was using for like 2 months but now I can not read the serial output or uploads sketchs any more.

At first I thought the promblem was the cable or the atmega328 but now I suspect that the problem is in the ttl-usb chip on my board.

If I left my nano without toching it for a day or 2 then i can connect it to the pc and see the serial output for a few seconds before it starts to output garbage for a few seconds before it stops the comunication.

If i send serial from console I can see the RX led flashing but not the TX, the same happend when I try to upload a sketch.

So i was wandering is there a way to use my Arduino Uno between my computer and my nano to monitor nanos' serial output? I do not have an usb-serial converter and I am not able to get one for the next 2 weeks (I live in the midle of nowehre in a 3rd world country)

Thank you!
PS: Sorry for my terrible english, it is not my first language.
PS2: Is it bad if i connect a digital pin (output high) to an analog pin to read the voltage? i did that just before i started to have problems to sense soil humidity

2

So your Nano serial port has problems? Try disconnecting everything. Does the board show up under Tools>Port?

3

Thank you for your reply.

Yes the board shows up.

I found this, so i will try to use my uno board to comunicate with the nano

I will try to test it and report the reesult, if it works for me it could work for someone else.

4

The board shows up?
So here's your scenario as I understand it:
You have a clone Nano that you have been using, and now it is acting up? When you leave it for a few days, it works for a bit and then starts outputting garbage? And then it shuts off? Maybe it is the output buffer filling up. Does your board have a CH340g or a FT232? Try a different terminal program.

5

And yes, you can use a Uno as a USB-Serial converter. But then you might as well use it as a ISP as well.

6

Isaac96, thank you!

I removed the atmega from my UNO and connect the following

Arduino Nano
====== ====
gnd => gnd
5V => Vin
TX => TX
RX => RX

Now i can see the serial output with no issues but when I try to upload an sketch i get the following
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x98
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x66
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xe6
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x06
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x7e
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x66
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x86
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xf8

Thank for your help!

7

Actually I realized it did not worked, it only worked for a couple of minutes and stoped working.

So, i guess the problem is not just the usb-ttl chip.

Thank you anyway!!!

8

Connect things up like this:
Uno Nano
5V 5V
GND GND
TX TX
RX RX
Vin needs at least 7V to output 5V.
Actually, I'll bet you chose "Arduino Uno" in Tools>Board when you tried to upload. I do that a lot.