Dear All, I'm new to Arduino and hope you can help. My setup is simple: (Arduino GND) -- resistor -- LED -- manually connecting/disconnecting wire -- (Arduino PIN set to HIGH 5 V) When I now cut the wire to the LED, will the command digitalRead read LOW? Will this work? void loop() { digitalWr…

If need be, you can use an Arduino i/o pin as both an output and an input pin. [image] Share tips you have come across General Electronics Per image #3 in post 331. Made some of these boards a few weeks back. They greatly speed up wiring and in checking out that code wi…

Post a schematic showing the arrangement of the components and connection to the Arduino. What Arduino?

Thanks for your answer. I plan to use Arduino Uno. Here is a similar schematic [cut_wire] Is there a way to detect, if the LEDs are one without using any other component? Probably not, because the pins to the LEDs can either set to input or output. Not both at the same time.

Think about what you just wrote. The LED was powered and had light. You cut the wire and there is no power to the LED. You can use your program to change the pin from output to input and read the status of that same pin. But what is there to be read? Nothing. Actually is will be undefined because it…

What’s your necessity of removing GND from the LED string ? If you want the LEDs OFF, just turn them OFF.

In that scenario, if you remove an LED, the associated pin will be floating so its state is indeterminate. This page may be of interest.

Thanks, I want the switch to replace by an iron ball. This ball is released manually and starts a stopwatch. Another sensor is detecting falling the ball on a plate and stops the time. It will take about 500 ms. I don't want to use another pins, because I will need them for further sensors and a di…

@christoph1706 , your topic has been moved to a more suitable location on the forum. Introductory Tutorials is for tutorials that e.g. you write, not for questions. Feel free to write a tutorial once you have solved your problem :wink:

Addressing your original enquiry, can you tell if the LED is disconnected? Indeed you can, at least for red LEDs (or any) whose threshold voltage is less than 2 V. You have the LED connected to ground with a resistor to the I/O pin. Set as OUTPUT, if you write it LOW, the LED is off and if you w…

Simplest way to detect, if LED i manually disconnected

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LarryD September 27, 2021, 4:27pm 8

If need be, you can use an Arduino i/o pin as both an output and an input pin.

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Simplest way to detect, if LED i manually disconnected

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