debounce - De-bounce circuit?

I have a laser sensor that randomly triggers on sunlight.The signal is fed to an opti-coupler to a FTDI chip.I am looking for advice for the easiest solution to take out these false positives which can be up to 250 ms.The problem appears to be the opto-coupler which is switching at less than 1 V DC and simple resistor / capacitor circuits take to long to discharge. :(I'm guessing it's going to be some sort of logic circuit.Any guidance given would be appreciated.EditCurrently under the winter sun where - worst case is 250ms / Second...Read more

debounce - minimal code for multiple buttons de-bouncing

i have 4 buttons attached to 4 pins configured as inputs with internal pull-up activated...is this function sufficient to get a debounced state of the pressed button?byte buttonPressed(){ byte btn = 0; if (digitalRead(30)==LOW) btn = 1; else if (digitalRead(9)==LOW) btn = 2; else if (digitalRead(31)==LOW) btn = 3; else if (digitalRead(8)==LOW) btn = 4; delay(20); return btn;}any strictly necessary improvements are welcome......Read more

Contact Bounce - Simple Debounce RC Circuit Question

I got this circuit from an example.simulate this circuit – Schematic created using CircuitLabWhat kind of circuit is this? I know its an RC circuit and I also know that its designed to be a simple switch debounce circuit. Is it also a kind of filter circuit? (low-pass/high-pass/etc.)The EXAMPLE stated that this is one simple version of a debounce circuit.How does this circuit help eliminate contact bounce?If it does eliminate contact bounce:How much bounce will this current setup eliminate? What will the voltage and current be at "A"?If I...Read more

Do we need to debounce the switch for key release

I understand that key debounce has to be considered either in Hardware (HW) or in software (SW) when we press a switch (to avoid make and breaks). Do we need to take care of key debounce even for key release? (make and break is possible even during release I guess). But since we are considering debounce for key press actions (I am considering in SW), anyway we won't get key pressed output even if "make" is detected when we release the key. If we go for hardware based key debounce (I am not hardware person), does it take care of both press and r...Read more

debounce - Non-TTL debouncing

This is probably simple, but I'm not an ee.A closet with 4 doors, each has a normally-closed pushbutton connected to 5V source on one end and (to the same) 5V relay which controls the 220V (AC) of the room lights. So the doors connected to the relay directly, not through a digital relay driver.The problem : when either door closed, the door physically bounces, regardless of the pushbutton's electrical bounce. And so I need to do around 0.75 second debouncing when the door gets closed (switch gets open), most circuits i see involves push-up/d...Read more

debounce - 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.EDITI would like to implement a hardware debounceMy primary problem is that I need to have my VCC on pin 5 and my ground on pin 3 in order to have my LEDs also work. And I don't know how to make the debounce work properly with that setup....Read more

debounce - RC debouncer circuit does not work

I tried two circuits below, none of them seems to be working (I used 74LS04 and 74LS00), the output doesn't change when I press the switch. I found that the voltage at point "A" doesn't drop below 0.8V (stays around 2V) when the switch is pressed. My guess the reason is that: when the switch is pressed, the capacitor starts to discharge, but there is a also a current flow out of the logic gate to ground thru R2, caused a voltage drop across R2, so that the voltage at A can not reach logic "0".Any other ways to make it work? Thanks much!...Read more

debounce - Manual Demonstration Circuit for 74HC595 Shift Register

I am trying to create a manual demonstration circuit for a 74HC595 shift register. Se my circuit below. The problem I am having is that I am only getting a +0.7V signal to the data, clock, and latch pins of the 74HC595 when one of the buttons are pushed. The S4 RESET switch works fine (normally high at 5V, press switch to bring down to 0V), however S1, S2, and S3 do not accomplish the reverse scenario (normally LOW, press switch for HIGH) correctly. You will note that I am also trying to debounce the switching with a capacity or resistor. I su...Read more