Questions tagged [debounce]

When a mechanical switch closes it's contacts typically do not close "cleanly" and tend to bounce or chatter. This rapidly switching signal could be misread in certain situations so it is usual to attempt to reduce this bouncing to ensure a clean switch detection. the danger is that if the switch is not de-bounced you can detect multiple events from one opening or closing. Can be accomplished using analog circuits or digital circuits.

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1answer
129 views

Relays for Logic - Current and debouncing?

Im just doing a little project for fun using relays to build logic circuits, and just have a few "thinking outloud" type questions... 1) Any contacts that can make a loop back to the power supply ...
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1answer
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Choosing transistor for a raspberry pi switch

I'm trying to design a circuit that will control the power to a raspberry pi with a button. The basic usage is: first button press-> rasp powers up. second button press-> rasp continues with power ...
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How can a shift register be used to debounce a switch?

This is the problem: This is the proposed solution: What I don't understand: The button bounces in the setup/hold time of the input of the circuit, making the FF go into a metastable state whereby ...
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1answer
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Is it possible to use just a capacitor to debounce a button?

I have been wondering: why cannot you just hook up a capacitor to a button to debounce it? I have been figuring out how to reduce the work my microprocessor has to do, but I have very limited space on ...
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2answers
442 views

Adding switch debounce to discharge circuit

We use the attached circuit for some diagnostic timing prior to doing experiments. Basically when the momentary switch is closed, from a location away from the generator box, the left side of C2 is ...
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3answers
9k views

AVR Button Interfacing

I am a beginner of the micro-controller and I have the kit for AVR. I am currently using an ATMega16 to learn the basics. I have tried a few simple experiments with this micro-controller using LED's. ...
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3answers
224 views

Capacitor and ISP issue

If I remove C5 I am able to use ISP. However, with C5 on board ISP programming fails... Capacitor is for button debouncing. What is the quick workaround to have ...
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1k views

Physics behind switch bounce when opening?

I was surprised to learn that a mechanical switch (SPST) bounces when it is opened. What causes the contact to temporarily return to touching? Does this phenomenon only happen with certain types of ...
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2answers
1k views

How to eliminate the forbidden state in an SR latch?

I'd like a latch where the output only changes when both inputs have changed. If only one input has changed, the latch output should stay constant. Here's the state table I want: ...
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2answers
188 views

Time parameters of pressing a tact button by people

Sorry for bad English. How fast people can press a tact button? I.e. what is minimal time of holding a button pressed people can get? What is typical bouncing time when people press tact button? I ...
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1k views

Does a switch need to be debounced when opened?

Suppose that an input on a microcontroller has a pullup resistor to 5V and a switch to ground (normally open) connected to it. I know that a switch should be debounced (in my case, in software) when ...
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1answer
2k views

How is this Pushbutton Debounce code?

I am monitoring a pushbutton with a microcontroller where I am trying to take care of four things together: 50-msec debounce upon push-begin and 25-msec debounce upon push-release identify a short-...
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Checking for short vs long press with debounce

I'm a complete beginner with Arduino but have done quite a bit of searching and can't seem to fix this problem. I'm trying to create a procedure that is repeatedly called in the main ...
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2answers
10k views

VHDL debouncer circuit

I'm working in a digital engineering lab and I'm trying to figure out how this debouncing circuit works. It's provided as-is by Xilinx but I'm not quite sure why it does what it does. Any pointers, ...
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3answers
3k views

Debouncing this Rotary Encoder Switch

I have this rotary encoder and I am not quite sure how to debounce the internal push button switch (shown in the SW02 diagram). Any help would be appreciated, I'm a noob with this stuff. EDIT I ...
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7answers
21k views

Debouncing buttons

I recently read an article about button debouncing and was wondering if I should keep this in mind when working with, for example, an Arduino (ATMega mC)? I assume it is an issue, especially when ...
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1answer
504 views

Spartan-3E to PIC16f887

I am a beginner wanting to know how to interface the spartan 3e board with the pickit2- PIC16F887. I have so far connected j2- pin a6(spartan) to port a Pin1 on the PIC, the ground Pins and j2 pin e7 ...