Tutorial 4 - Further explanation of 10K ohm resistor

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dannymosquito
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Tutorial 4 - Further explanation of 10K ohm resistor

Post by dannymosquito » Fri Aug 13, 2010 1:16 am

Hi Everyone and thanks for everyones replies to my last posts.... Fixed my soldering wows by running out and purchasing a bread board... :D
I was hoping someone might be able to expand on the explanation of the need of the 10K resistor. In the explanation there is talk of an in-between state of the switch. I don't understand this.... The button can either be ON (shorting) or OFF no connectivity...Isn't that right... Is the in-between state when it is just barely making contact before its released?

One other things thats been bugging me is the connection on the PickIT 2 how does everyone hook this thing to their circuit... are you just shoving wires straight into it. I see pictures of sockets that seem to be made for the PickIT 2. Anyone know what these are called so I can order some?

Thanks again everyone.... :D :D :D
Danny
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bitfogav
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Post by bitfogav » Fri Aug 13, 2010 2:14 am

One other things thats been bugging me is the connection on the PickIT 2 how does everyone hook this thing to their circuit... are you just shoving wires straight into it. I see pictures of sockets that seem to be made for the PickIT 2. Anyone know what these are called so I can order some?
Hi Danny

So you got yourself a breadboard? that will come in handy! :)
So for the pickit2 and how I connect it to the breadboard is by 5-6 pin header, these can come in rows of 40 pins and you just cut them down to size, Or yes you could just shove wires into the pickit2 to your breadboard?

heres a picture to show you what the pin headers look like

Image

Ebay is a good souce for these :)

Maybe Brad can explain why we need the 10K resistor and the in-between state better?
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brad
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Post by brad » Fri Aug 13, 2010 6:19 am

Good question about the 10k pullup resistor :)

Something quite important to remember is that both a logic 1 and a logic 0 are actually SOMETHING. I guess we all understand that a logic 1 is 5volts, but a logic 0 is just not NOTHING - it is actually ground or the negative terminal of the battery.

An open circuit or in-between state of the switch is neither +5v OR ground it means that the input is connected to no-where and the internal circuits are pretty much controlling themselves which means they are susceptible to noise.

dannymosquito
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Post by dannymosquito » Fri Aug 13, 2010 3:22 pm

Thanks heaps Brad and Gav.... I will order the pin header right now. Brad I understand exactly what you mean now, excellent explanation. Now I just have to get my head around the assembly language which is slowly starting to sink in.

:D :D :D
Danny
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Post by brad » Fri Aug 13, 2010 9:27 pm

I'm glad I could help out :D

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