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)?
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.
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
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!
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?
Hello,
I did yesterday for a project of mine and it is also documented in the datasheet for the I2C I/O chip PCA9555.
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| Asked: 8/23/16, 3:19 PM |
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| Last updated: 10/5/16, 8:22 PM |
Thanks!