Question about pins 0 and 1

Hi there,

I'm finishing a project on an Arduino UNO. Everything works very well but to completely nail it, I would need an additional digital output pin to control a TIP120 transistor. Can one use either PIN 0 or PIN 1? I haven't used them so far since they are RX/TX pins.

I know I could also use the analog PINS as digital, but I run out of them as well.

Thanks in advance!

Just make sure to disconnect what you put on pins 0 and 1 before doing any Uploading.

[quote author=Runaway Pancake link=topic=204657.msg1506810#msg1506810 date=1387031683] Just make sure to disconnect what you put on pins 0 and 1 before doing any Uploading. [/quote]

Ok, should be no problem... but why? :astonished:

Hi, if you leave the transistor connected to pin 1 or 2 while you load a sketch, the signal will turn on and off what ever the transistor is driving.

So to prevent this disconnect them to allow safe program loading.

Tom..... :)

Hope it makes sense, just got home after 3 1/2 hour round trip to pick daughter up from Taylor Swift concert.( 2:05am local)

TomGeorge: Hi, if you leave the transistor connected to pin 1 or 2 while you load a sketch, the signal will turn on and off what ever the transistor is driving.

So to prevent this disconnect them to allow safe program loading.

Tom..... :)

Hope it makes sense, just got home after 3 1/2 hour round trip to pick daughter up from Taylor Swift concert.( 2:05am local)

Yeah, I think I understand. Thanks a lot.

PS: Sorry about the concert bro!

marcalcc:
Ok, should be no problem… but why?

TomGeorge:
Hi, if you leave the transistor connected to pin 1 or 2 while you load a sketch, the signal will turn on and off what ever the transistor is driving.
So to prevent this disconnect them to allow safe program loading.

Right, you don’t want the Uploading to run the circuit, too.
And what you hang on 0 or 1 can negatively affect “Uploadability”.

Right, you don't want the Uploading to run the circuit, too. And what you hang on 0 or 1 can negatively affect "Uploadability".

Great. It should be no problem in my case. I'm using it to manage some solenoid valves, but at the time of programming and testing I'm in my office on dry dock.

Thanks again!

Now that I think of, if I were to use the pins 0 & 1 as a input, I could just add a diode in between and be done with it, right?

marcalcc: Now that I think of, if I were to use the pins 0 & 1 as a input, I could just add a diode in between and be done with it, right?

I'm not sure how you mean. Sometimes, I don't get the deal with you "Question Guys"...

Howbeit, see how that works for you. So long as machinery isn't involved, give it a go, I say. Maybe experience will prove a better teacher than I. . Make sure that you can Upload, too.