UNO R3 card maintenance

Do folks clean pin-holes (breadboards) and connection ports on the UNO-R3 card? I find inadvertent (“HIGH” (“1”) values with no action on the board such clicking a push-button or connecting jumper from pin hole to connection port.

Tom Kane / Canada



edit: I should say the 3 ways with Arduino. I believe there are some devices with internal pulldowns

Although it was never documented in the Arduino Language Reference, both the Arduino SAMD Boards and Arduino Nano 33 BLE's pins can be set to an INPUT_PULLDOWN mode using pinMode().

Do folks clean pin-holes (breadboards) and connection ports on the UNO-R3 card?

Never. Not even sure how I could do that. The sliding action of inserting and removing pins should keep the contacts clean.

I do keep my Arduinos away from chocolate cake.


Breadboards are prone to noise that could also cause those types of issue.

Along with wire jumpers not connected to anything, high humidity related static, extreme cold based static (yes that's a thing), badly routed wiring especially where higher than board level voltages are concerned.

It is also one of the reasons we often ask for pictures.

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