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Topic: Simple question about the demo projects with the Uno (Read 846 times) previous topic - next topic

DJRikki

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

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

You dont have to connect positive(red) wire to board. It just there for future use, so far its useless.

radman

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 am Last 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


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

...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

radman

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
you need to upload your photo to your choosen online photo storage site,eg photobucket


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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