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.
To ROBIN2 Good idea (no chocolate cake) Fortunately (I guess) I am diabetic, so the chocolate cake danger is not a threat to my UNO R3.
Thanks for the PULLDOWN suggestion. However, I am already using that practice; I learned it from another forum. Adding that feature (the actual resistor and the MODE) did not change the issue.
My next test will be disconnecting the wire from the Pin to see if that helps. If it does I have to suspect that the pin "socket" is damaged (hence, my thought about cleaning the connectin holes)..
I did have one odd occurrence with a different project; A jumper wire had excessive resistance (total about 3 ohms). WEIRD. After checking code and wiring I just guessed at the possible of a bad jumper. Replacing the jumper cured THAT problem. However, measuring resistance on my jumpers in this project did NOT show any excessive resistance; replacing jumpers did not correct the problem.
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.
Could you also take a few moments to Learn How To Use The Forum (https://forum.arduino.cc/index.php?topic=148850.0).
It will help you get the best out of the forum in the future.
Other general help and troubleshooting advice can be found here. (https://forum.arduino.cc/index.php?topic=52113.0)
"My next test will be disconnecting the wire from the Pin to see if that helps. If it does I have to suspect that the pin "socket" is damaged (hence, my thought about cleaning the connectin holes).."
Removing the write from the pin did not help. I also tried rebuilding the hardware on a new UNO R3; the same problem occurred!
BUT, I "tore down" the board and UNO wiring and re-built it. I also stripped down the sketch; thus far, the problem has not re-occurred!. SO, this might be solved. More to come after I add more of the steps I want in a now stripped-down" sketch.
Well, I tried to chose this "general discussion" forum, obviously misunderstanding the term "general." Please consider this item closed through user incompetence.
Simply EDIT your first post and add (SOLVED) to the end of the subject.
That is all you need to do.