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Does anybody know what is the shortest pulse width that the Raspberry Pi (any model) GPIO interrupt pins can detect? I have a project in mind, but the pulses would be between 5 & 17ns wide.

3

The GPIO peripheral is identical on all Pi models. The only difference is in the number of GPIO routed to the expansion header.

The Pi has a GPIO Asynchronous rising/falling Edge Detect mode.

See pages 99/100 of BCM2835 ARM Peripherals.

"Asynchronous means the incoming signal is not sampled by the system clock. As such rising/falling edges of very short duration can be detected."

I'm fairly sure that 4ns will be detected.

I don't know if this mode is the Pi default. You will have to experiment.

0

As joan has said this should be possible. 5ns corresponds to 100MHz and should be within the Pi capabilities. Your problem will be delivering the signal. A terminated transmission line would be required.

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