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### Topic: Simple question about the demo projects with the Uno (Read 1 time)previous topic - next topic

#### DJRikki

##### Sep 20, 2011, 03:43 pm
Hi there, just got my first Arduino to play with and already built the first two projects to get a feel for things.

My simple question (that is probably very silly) is, why do the tutorials ask me to write up a positive feed to the breadboard when nothing appears to connect to it?

eg:

This type of thing appears in the blinking LED demo from my Sparkfun kit and also the second demo with 8 LEDs.

Many thanks,

Rik

#### johnwasser

#1
##### Sep 20, 2011, 03:48 pm
Probably just easier to start with a diagram that has power hooked to the breadboard.  You can ignore the unused power connection.
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#### BAXX

#2
##### Sep 20, 2011, 03:49 pm
You dont have to connect positive(red) wire to board. It just there for future use, so far its useless.

#3
##### Sep 20, 2011, 10:59 pm
Quote
My simple question (that is probably very silly) is, why do the tutorials ask me to write up a positive feed to the breadboard when nothing appears to connect to it?

I am glad you asked that question because I was wondering too.

Here are a couple of other newbie questions I hope people will not mind me grafting on here;

• How did you get the circuit diagram to insert into the post?

• If I put a continuity meter between the 5V and the GND in your diagram I get a "bell" i.e. short. That is not what I was expecting, but there is probably a very good reason for it which I hope somebody can (simply) explain.

#### AndyCC

#4
##### Sep 21, 2011, 12:43 amLast Edit: Sep 21, 2011, 12:46 am by AndyCC Reason: 1
The circuit picture appears to be from Fritzing (fritzing.org).

Measuring continuity (or resistance) when there's power in a circuit is not going to be accurate. The voltage in the circuit can interfere with the voltage the meter sends down the line to check continuity. It's also a good way to fry your meter. Hope this hasn't happened to you!

If you get continuity between +5 and Ground with no power applied... I can't explain that one.

#### DJRikki

#5
##### Sep 21, 2011, 02:38 am

Quote
My simple question (that is probably very silly) is, why do the tutorials ask me to write up a positive feed to the breadboard when nothing appears to connect to it?

I am glad you asked that question because I was wondering too.

Here are a couple of other newbie questions I hope people will not mind me grafting on here;

• How did you get the circuit diagram to insert into the post?

• If I put a continuity meter between the 5V and the GND in your diagram I get a "bell" i.e. short. That is not what I was expecting, but there is probably a very good reason for it which I hope somebody can (simply) explain.

To put a picture into your post just get its URL and then do this :

Code: [Select]
`[img]http://www.aaaaaa.com/picture.jpg[/img]`

#### Texy

#6
##### Sep 21, 2011, 11:21 am
...to expand further, you need to upload your photo to your choosen online photo storage site,eg photobucket, etc, then put a link to that photo in your post.

Texy

#7
##### Sep 21, 2011, 08:37 pm
This has been a really helpful topic for me.

Quote
The circuit picture appears to be from Fritzing (fritzing.org).

Fritzing looks like a great way to generate pictures and schematics of sketches, it even shows connectivity and highlights things that are not connected.

Quote

Quote
To put a picture into your post just get its URL and then do this :
Code: [Select]
`[img]http://www.aaaaaa.com/picture.jpg[/img]`

I'll be generating some images with fritzing, putting them on photobucket and embedding them in topics very soon

Quote
If you get continuity between +5 and Ground with no power applied... I can't explain that one.

I did get continuity without power applied but I was using a very cheap tester. I have borrowed a proper meter and it shows a resistance of about 0.9kohms between +5 and GND. So yes there was continuity but I guess the resistance means its not a short and it represents the power supply circuitry.

Thanks everyone.

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