• DIO
  • Beginner
  • 5 min
  • Microsecond pulse

Recipe · Beginner · DIO

How to pulse a GPIO in microseconds

DIO mode gives direct manual GPIO control. The wiki documents set, pulse <gpio> <us>, toggle, measure and reset.

Digital GPIO pins with logic signals.
A microsecond pulse is useful for reset, trigger, enable and timing experiments.

Wiring View

input BP DIO inputGPIOGNDBP GND
Generated from the wiring summary: input to BP DIO.
Step 1

Commands

Set the pin as output, pulse it, then reset the GPIO to a neutral input state when finished.

Result

What success looks like

The target reacts to the pulse, or a logic analyzer shows a short transition on the selected pin.

Troubleshooting

  • No shared ground between target and ESP32 Bit Pirate.
  • Target expects 5V logic while the ESP32 GPIO is 3.3V.
  • Wrong GPIO number or protected GPIO selected.
  • Pulse too short for the target input or too hard to see without a logic analyzer.

Next steps

  • Use toggle <gpio> <ms> for a repeated square wave.
  • Use measure <gpio> [ms] to check a returning signal.
  • Use the logic analyzer recipe if you need to verify timing visually.

Microsecond GPIO pulse FAQ

What can a short GPIO pulse be used for?

A short pulse can trigger a reset pin, enable input, latch, interrupt line or timing experiment when the target expects a simple digital transition.

How should I choose a pulse width?

Choose the pulse width from the target datasheet, a known reset requirement, or a logic-analyzer observation. The value should match the event you want the target to recognize.

Why reset the GPIO after the pulse?

Resetting the pin returns it to a neutral state and reduces the chance of leaving the target held high, low or actively driven after the test.

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