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Unread 28-12-2013, 08:34
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Re: 3V3 digital signal to the cRIO

Quote:
Originally Posted by yash101 View Post
An opto-isolator is a splendid idea that will almost always work. Why did someone not already bring it up?!?! Kudos to you .

Using an analog signal would be getting a little off from what we want here. For something like the raspberry pi or propeller would be hard to interface with a DAC/ADC couple. On the RPi, I don't know if you'd even have enough GPIO!
I think the idea behind the analog inputs is to use the analog module on the cRIO because it doesn't have a pull up resistor like the digital ones do. You can make the analog input behave like a digital input and return true if the voltage is above 2v, and false if it is below, without having to worry about the pullup resistor to 5v.