Author Topic: What type of output pin can I share on a single GPIO  (Read 539 times)

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Offline drakejestTopic starter

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What type of output pin can I share on a single GPIO
« on: August 31, 2020, 03:09:07 pm »
So i am very limited on my GPIO with only 4 remaining, and using a portexpander seems to be unecessary. I have used 2 of this IC and 2 of this IC  And i need to read their status pins.

On the first IC i only need to read there are in total of 4 status pins, i do not need to know which one triggered the status so i would like to read it only using one pin, the pins seems to be an open drain type, so is it possible to share this? hopefully they can also have only one pull up the schematic kinda looking like this

On the second IC is a bit tricky since it takes 2 GPIO to read, 1 for selecting either channel and 1 for the actual reading, I could not identify what type of pins they though, this is my planned circuit

In total i have used 3 pins which leaves me 1 extra for whatever i might use it for.
 

Offline bson

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Re: What type of output pin can I share on a single GPIO
« Reply #1 on: August 31, 2020, 09:30:55 pm »
Drive channel select directly using the GPIO output, no need for a pull-up since they're inputs.
 


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