I have a PCB (let's call it remote PCB) on which I have 4 LEDs and 4 buttons mounted. The remote PCB is far away from my desk (about 12 feet away). The LEDs are used to indicate the status and the buttons are for various state inputs.

All of them are connected to UNO directly.

  1. I am planning to use a 10 pin IDC connector and IDC ribbon cable for the same.
  2. THe LEDs' current is about 2 mA each (white LEDs)
  3. The push buttons will make a ground connection when pressed, else the internal pull-up of the UNO will keep the GPIO at a high level.
  4. I have put a capacitor of 10 nF across the switch to address denounce.
  5. I have a series resistor of 1-kilo ohm for all four Switches on the remote PCB

I would like to know if this is okay? Will there be any problem due to the length. The LEDs are for indication and won't blink faster than 200 ms at any point in time. They will be used to indicate status which is very slow signals. Thanks in Advance!

  • This might work. I would occasionally expect there will be "unexpected" events. If this is for security or safety defiantly consider an alternative. If this is for fun, go for it. If it works as expected great. If not try something else.
    – st2000
    May 22, 2021 at 16:17

1 Answer 1


That is a big no-no. You are adding extremely long antennas to the Arduino asking for problems. At a minimum on the inputs add a 10K series resistor at the Arduino pins. My preference would be to put the capacitors at the arduino pins to help decouple noise etc as well as the pull up resistors on the wire side of the 10K resistors. Use a buffer of some type for the LEDs, a transistor would work. This may work but for how long and how many processors can you destroy over time.

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