• UART
  • Beginner
  • 5 min
  • Serial CLI

Recipe · Beginner · UART

How to probe a UART device with ping

Use UART ping to send predefined probes and detect whether an unknown serial target answers.

UART autobaud signal traces.
A practical ESP32 Bit Pirate recipe based on documented firmware commands.
Step 1

Commands

Run this sequence from the CLI. Adjust pins, addresses or filenames to match your own setup.

Result

What it means

A reply tells you the serial direction and baudrate are plausible before entering bridge mode.

Troubleshooting

  • Re-enter the selected mode setup if pins changed.
  • Confirm the target shares ground with the ESP32 Bit Pirate.
  • Start with short commands before using longer capture or bridge sessions.

Next steps

  • Use bridge for interactive access.
  • Try raw if replies are binary.
  • Use swap if nothing answers and wiring may be reversed.

UART ping probe FAQ

Why use ping before bridge mode?

UART ping sends controlled probes and looks for replies, which is safer than immediately typing into an unknown serial console. It helps confirm baud rate and wiring first.

What does ping prove on a UART target?

A UART ping proves more than line speed: it checks whether the target understands the expected command or probe pattern and whether the reply can be parsed by the current workflow.

Should I use read or raw after ping?

Use read for printable ASCII consoles and AT-style modules. Use raw when replies contain binary bytes, framing markers or non-printable protocol data.

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