using one of the pins as the power of another device

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Anonymous
Not applicable

Hi,

   

I have a problem with using GPIO pins. If I have nothing connected to the pin that I want to use, then it works well (it changes its value from 0 to 1 and from 1 to 0 if I want to), but when I connected VCC pin from another device to that pin, then I can't change port's value from 0 to 1. The idea is to make this external device run once in a while, so I want to let's say set the pin to which the VCC is connected to 1 every 10 seconds, and after that change it to 0 so that this external device will not be working more. Could anyone help me with this? I set the pin to digital output with the Strong Drive mode and Initial state drive to 0. And I'm using Port 1.5 which is pin 42.

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8 Replies
Bob_Marlowe
Level 10
Level 10
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How much current is your external device drawing from the PSoC pin?

   

Which board are you using? CY8CKIT-0??

   

 

   

Bob

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Anonymous
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I'm using CY8CKIT - 049 and the external device is ESP8266 module when I connect it to the VCC pin then it works just fine, the problem is when I'm trying to change from VCC pin to that 1.5 Port 

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Anonymous
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The GPIO pins have a current limit (25 mA iirc), and the device you are wanting to power is 56 mA of typical draw (up to 150 if active radio...)

   

http://espressif.com/sites/default/files/documentation/0a-esp8266ex_datasheet_en.pdf

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Anonymous
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Thanks for reply, so is there any way to do that as I described? or it has to be connected to the VCC pin?

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Bob_Marlowe
Level 10
Level 10
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Consider using 3 pins in parallel,

   

 

   

Bob

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HeLi_263931
Level 8
Level 8
100 solutions authored 50 solutions authored 25 solutions authored

Or just use a PNP-transistor to turn your device on and off.

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Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hi Mario,

To increase the total source or sink capabilities of the circuit, GPIO pins can be ganged.  Please refer section 6.11(page 57) in this document.

http://www.cypress.com/file/127101/download

Best Regardss,
VSRS

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Anonymous
Not applicable

Thanks for Your replies, I think I will try with the transistor

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