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IO Pi plus as switch

1191 Views - Created 19/06/2017

19/06/2017

Posted by:
Battos

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Hi,

I bought an IO Pi plus extension for my Raspberry pi 3 Model B.

I have an output +2.5v on an other device and i would like to use the IO Pi Plus to act as a switch in order to closing and opening the circuit between the +2.5v and the ground of the other board.

Currently, i haven't found a way to doing this with the IO Pi plus.

My question is, is there a way of programming the IO Pi Plus extension board to act like i want ? 

Thank you in advance.

19/06/2017

Posted by:
andrew

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Location:
United Kingdom

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Hi

The IO Pi Plus will not be able to switch the +2.5V directly as it can only output 5V from its pins.  What you will need is an external transistor to act as a switch.  

The circuit below shows what need to use.  An NPN transistor is connected between the +2.5V and GND acting as the switch.  A 500R resistor is connected between the IO Pi output and the transistor gate to limit the current to 10mA so that when the IO Pi output goes high it will turn on the transistor allowing current to flow.  The 10K resistor is there to pull the gate low when the IO Pi output goes low ensuring the transistor fully switches off.

You will need to connect the ground on your other device to the ground on the Raspberry Pi to ensure they both have a common ground.

Post image

AB Electronics UK Tech Support

19/06/2017

Posted by:
Battos

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Hi,


Thank you very much for your explanation. I was afraid to be obligated to add a component. 
I will do what you explained.


Thank you again !

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