Are pullup resistors required when using the ind.i/o board?

Hello,

Does the ind.io board require pullup resistors on the digital pins?  If so, can I access the internal resistors using pinmode(INPUT_PULLUP)?  

 

 

 

 

Michael Mesford
Michael Mesford
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Asked on 8/23/16, 3:19 PM
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Thanks!

Michael Mesford
on 8/23/16, 10:01 PM

No, they're not needed. If you're powering Ind.io e.g. with 24 VDC, then 24VDC on input pin is HIGH, 0 VDC or disconnected pin is LOW.

Richard Fela
Richard Fela
32
| 3 1 2
Answered on 8/25/16, 7:27 AM
1
vote

Today I run in a problem regarding pullups, so I had to examine this matter completely.

The fact is that I had a switch which connects an input to ground, so I needed a pull-up to get the desired input change.

The only method to activate an input pull-up is the following:

#define MANAUT 4                                     //deviatore manuale/automatico

Indio.digitalMode(MANAUT,INPUT);   //set as input

Indio.digitalWrite(MANAUT,HIGH);    //switch on pull-up

The keyword INPUT_PULLUP has no effect in the Indio library.

Hope this helps

Stefano Giuseppe Bonvini
Stefano Giuseppe Bonvini
577
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Answered on 10/4/16, 2:29 PM
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Have you tested this in a circuit? I'm not sure the Indio board has pull-up resistors. It seems like your code will set the pin to Output and you'll get a short between 24v and ground. Be careful testing this!

Michael Mesford
on 10/5/16, 8:07 PM

Hello, more on this subject. After having used this solution on several machines, all of a sudden it doesn't work anymore. The very same code does the wrong thing, which is turning the input to output. Has anything changed in I/O design or libraries?

Stefano Giuseppe Bonvini
on 7/9/17, 12:00 PM

Hello,

I did yesterday for a project of mine and it is also documented in the datasheet for the I2C I/O chip PCA9555.

Stefano Giuseppe Bonvini
Stefano Giuseppe Bonvini
107
| 4 1 3
Answered on 10/5/16, 8:22 PM
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Asked: 8/23/16, 3:19 PM
Seen: 3494 times
Last updated: 10/5/16, 8:22 PM