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Topic: Multiplexing Rotary Encoders (Read 1 time) previous topic - next topic


Feb 22, 2019, 02:08 pm Last Edit: Feb 22, 2019, 02:10 pm by PerryBebbington
I find this very useful for that kind of wiring on strip board and similar
Vero wiring tool

Today I borrowed a multimeter
You really should buy one. Even one costing £20 or so will make life so much easier. Not having one is like a joiner not having a hammer :)


Hey people,
Not sure if I have to ask in another thread but, because in this one, there's a "history" I'll ask here.

The encoders, as I said feature a push button each.
When I'm connecting them to either a multiplexer or in a matrix, do I have to use pull down resistors? And what determines the value of each resistor?
If I'm using a multiplexer,  do I have to have one on the ground pins of the ic, or do I need one for each button (I believe the latter).

Thank you


Feb 25, 2019, 11:59 pm Last Edit: Feb 26, 2019, 12:02 am by PaulRB
You only need one resistor per input pin. Wire your switches between the input pin and ground, and you can use the Arduino's internal pull-up resistors. The value of pull-up/pull-down down resistors is not critical. If using external resistors, anything between 4K7 and 47K should be fine. The internal pull-up resistors are around 30~40K.

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