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External connections when using internal pullup/down resistor

jnich3
New Contributor I
1,004 Views

Is this the way to wire up the edison if using internal pullup resistors?

(this is a sparkfun gpio block, one side of switch is connected to a gpio pin, other side of switch is connected to gnd)

Are there any schematics of what is going on internally with the edison pullups? Shouldn't I also be connecting vcc in somewhere? Or not?

Sorry if this is a very naive question.

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1 Solution
idata
Community Manager
145 Views

Hi Jayls,

Thanks for contacting us! Don't worry, we are happy to help you with any questions you have.

 

Regarding your first question, yes, it is the way to wire if you are using an internal pull-up resistor. As a reminder, you should set up the internal pull-up previously, if need help with this let me know please.

The following image is an example of how the internal pull-up works, when the pushbutton is open (unpressed) there is no connection between the two legs of the pushbutton. Because the internal pull-up is active and connected to 5V, we read HIGH when the button is open. When the button is closed, we read LOW because a connection to ground is completed. For that reason it's not necessary to connect an external VCC.

 

Hope this information helps, let me know if you have any questions.

Regards,

 

-Yermi.

 

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1 Reply
idata
Community Manager
146 Views

Hi Jayls,

Thanks for contacting us! Don't worry, we are happy to help you with any questions you have.

 

Regarding your first question, yes, it is the way to wire if you are using an internal pull-up resistor. As a reminder, you should set up the internal pull-up previously, if need help with this let me know please.

The following image is an example of how the internal pull-up works, when the pushbutton is open (unpressed) there is no connection between the two legs of the pushbutton. Because the internal pull-up is active and connected to 5V, we read HIGH when the button is open. When the button is closed, we read LOW because a connection to ground is completed. For that reason it's not necessary to connect an external VCC.

 

Hope this information helps, let me know if you have any questions.

Regards,

 

-Yermi.

 

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