• Expander
  • Intermediate
  • 5 min
  • Expansion link

Recipe · Intermediate · Expander

How to connect the ESP32-C5 Expander

Expander mode selects its RX/TX pins, performs a handshake, then bridges your terminal to the expansion module. You do not need to configure UART mode first.

Terminal shell showing a command prompt.
Use this when the expansion board should answer the Bit Pirate handshake.

Wiring View

Expander BP TXBP RX GPIORXBP TX GPIOGNDGNDVCCsupported supply
Generated from the wiring summary: Expander to BP.
Step 1

Commands

Entering Expander mode asks for RX and TX GPIOs, configures UART at 115200 8N1, sends the handshake, then opens the bridge.

Result

What it means

The host and expander agree on wiring and UART settings. Commands typed after this point are sent to the expander until exit.

Troubleshooting

  • RX and TX not crossed.
  • Expander not powered or held in reset.
  • Wrong GPIOs selected during setup.
  • Old expander firmware that does not answer the handshake string.

Next steps

  • Record the working RX/TX GPIO pair.
  • Use exit to return to ESP32 Bit Pirate.
  • Update the expander firmware if the wiring is correct but handshake never appears.

ESP32-C5 expander bridge FAQ

What does the ESP32-C5 expander add?

The expander acts as a radio coprocessor for the main ESP32 Bit Pirate device, notably for 5 GHz Wi-Fi workflows that the main ESP32-S3 cannot handle alone.

When is the ESP32-C5 expander the right choice?

Use the expander when the recipe needs the C5 side of the project, such as extra radio capability or the documented S3-to-C5 bridge workflow. Normal local UART, I2C, SPI and GPIO recipes do not require it.

Is the expander required for normal Bit Pirate recipes?

No. Most protocol recipes run directly on the main board. The expander is only needed for workflows that depend on the extra radio coprocessor features.

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