I need to simulate realistic button presses that include bounce patterns..but digitally with something like an FPGA to test my debouncing code. How do I generate those noises?
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2\$\begingroup\$ Why not test it by pressing a button? \$\endgroup\$– HearthJun 3, 2021 at 3:27
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\$\begingroup\$ I need to test it for a lot of buttons..something that I can do by running a script \$\endgroup\$– Baba YagaJun 3, 2021 at 3:32
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2\$\begingroup\$ How about a relay? \$\endgroup\$– HearthJun 3, 2021 at 3:55
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\$\begingroup\$ I suppose you could use a DAC. But seems like more trouble than its worth. \$\endgroup\$– DKNguyenJun 3, 2021 at 4:07
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\$\begingroup\$ On board? Use a real button. \$\endgroup\$– Mitu RajJun 3, 2021 at 4:46
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The press of a button is not really noise, they are mostly at the logic level of either 0V and VDD.
When bounce occurs, it would bounce a few times between VDD and GND, but there is not really much transient noise, or they appear because of the acquisition speed of the oscillo.
You can take a button and record a few presses on an oscilloscope, and then program the pattern in your FPGA.
If you really want to make transient peaks, you can add a small cap on the line and generate very short pulses.
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\$\begingroup\$ currently I'm able to generate very small pulses of periods in the range of microseconds but the pulses that don't go up to VDD are the ones I can't generate and the noise around the edges \$\endgroup\$ Jun 3, 2021 at 11:09
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\$\begingroup\$ Damien - Hi, That image seems to have come from somewhere else, so in order to comply with this site rule, can you edit your answer and add a link back to the original source web page, please? Thanks :-) \$\endgroup\$– SamGibson ♦Jun 3, 2021 at 13:01
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\$\begingroup\$ @BabaYaga you can add a simple RC filter on the pin and with short pulses you can do the ones that don't go to VDD. \$\endgroup\$– DamienJun 4, 2021 at 4:14