On the DIN module there is a lot of 10k resistors.
My question is:
what is meant by a pull-up resistor? what is different with these compared to the other ones?`
I understand what they are for, but I’m writing an ordering list right now over the parts of the DIN board, so it would be nice to know what I have to order
A pull-up resistor holds an input pin high if the pin isn’t connected to anything (ie. connected to an open switch is the same thing). If the pin is brought low by a switch to ground or a low output pin, then current flows from the positive rail through the pull-up resistor to ground/low output pin.
Thus 10K is used because it’s low current (0.5 mA @ 5V).
The cheapest, ceramic 1/4 watt 5% tolerance ones are fine. And if you pay more than US$0.01 each for them, you’re getting ripped off. Best to order in bulk from Futurlec and get the chips for US$0.35 too.