• UART
  • Intermediate
  • 3 min
  • Serial CLI

Recipe · Intermediate · UART

How to emulate a UART device

Use UART emulator mode to test how another board behaves when a serial peripheral sends expected data.

GPS receiver with serial signal.
Start with read-only checks, then move to write, replay or automation only when the setup is understood.
Step 1

Commands

Use the shortest command path that matches the documented firmware workflow. When a mode needs setup, follow the prompts shown on first entry.

Result

What it means

The command path is working when the target responds and the firmware prints the expected menu, status or captured data.

Troubleshooting

  • Re-enter the mode setup when pins or peripherals are not already initialized.
  • Check common ground and target voltage before blaming software.
  • Prefer Serial CLI for long captures or high-volume output.
  • Repeat the read or capture to confirm stability.

Next steps

  • Save the output in your project notes.
  • Compare the result with the full wiki page for mode-specific details.
  • Create a shorter alias if you repeat this workflow often.

UART device emulator FAQ

What is the UART emulator useful for?

It lets another board see predictable serial traffic without the real peripheral attached. That is useful for testing parser code, GPS-style input handling or boot-time serial expectations.

Does the emulator prove the real peripheral will work?

Not completely. It proves the host can receive expected UART text at the chosen baud rate, but the real module may still differ in timing, sentence format, voltage level or flow-control behavior.

What does GPS emulation send to the target?

It sends GPS-like serial sentences so a target that expects a receiver can be tested without satellites or a real GPS module. The value is repeatable input for firmware and UI validation.

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