pull-up or pull-down resistors?

Design Concepts
1

hi can any one tell me if i still need to connect the resistors to the inputs of the din module if im using normally open buttons?

and can i use this link http://www.ucapps.de/mbhp/mbhp_dinx4_32buttons.pdf as my guide line?

10x

2

Yes, you need the Pull-ups

These pull-up resistors are required if buttons are connected to the digital inputs. They ensure that the pins are supplied by defined voltage levels when a button is not closed (pressed). If you are using the DIN module with a MIDIO128, you maybe want to drive the pins “high-active” (which means: +5V = on, 0V = off). In this case please solder the two red isolated cables not to 5V, but to 0V (Vss), so that the resistors act as pull-downs.

Your MIDIbox will send a lot of random MIDI traffic without these pull-ups, so don’t miss them!

Source: http://www.ucapps.de/mbhp_din.html

Greets, Roger

3

hi can any one tell me if i still need to connect the resistors to the inputs of the din module if im using normally open buttons?

This is not a special case.

Normally-open switches (NO) are the standard.

For the record, if you were using normally-closed switches (NC), you would still need the pull up/pull down resistors.

4

cheers