Hello, Board!

You're now ready to do a consistency check!

✅ Connect the USB-C port of the board to your computer and enter the hardware-check directory in the workshop repository:

cd intro/hardware-check

To test Wi-Fi connectivity, you will have to provide your network name (SSID) and password (PSK). These credentials are stored in a dedicated cfg.toml file (which is .gitignored) to prevent accidental disclosure by sharing source code or doing pull requests. An example is provided.

✅ Copy cfg.toml.example to cfg.toml (in the same directory) and edit it to reflect your actual credentials:

⚠️The 5 GHz band isn't supported in ESP32-C3, you need to ensure you are using a Wi-Fi with active 2.4 GHz band.

$ cp cfg.toml.example cfg.toml
$ $EDITOR cfg.toml
$ cat cfg.toml

[hardware-check]
wifi_ssid = "Your Wifi name"
wifi_psk = "Your Wifi password"

✅ Build, flash and monitor the project:

$ cargo run

Serial port: /dev/SERIAL_DEVICE
Connecting...

Chip type:         ESP32-C3 (revision 3)
(...)
Compiling hardware-check v0.1.0
Finished release [optimized] target(s) in 1.78s

[00:00:45] ########################################     418/418     segment 0x10000

Flashing has completed!
(...)
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
(...)
(...)
(...)
I (4427) wifi::wifi: Wifi connected!

🔎 If cargo run has been successful, you can exit with ctrl+C.

🔎 cargo run is configured to use espflash as custom runner. The same output can be achieved via:

  • Using cargo-espflash: cargo espflash flash --release --monitor
  • Building your project and flashing it with espflash: cargo build --release && espflash target/riscv32imc-esp-espidf/release/hardware-check This modification is applied to all the projects in the training for convenience.

The board LED should turn yellow on startup, and then, depending on whether a Wi-Fi connection could be established, either turn red (error) or blink, alternating green and blue, in case of succeeding. In case of a Wi-Fi error, a diagnostic message will also show up at the bottom, e.g.:

Error: could not connect to Wi-Fi network: ESP_ERR_TIMEOUT

⚠️ You will get an ESP_ERR_TIMEOUT error also in case your network name or password are incorrect, so double-check those.

Extra Information About Building, Flashing and Monitoring

If you want to try to build without flashing, you can run:

cargo build

You can also monitor the device without flashing it with the following command:

espflash monitor

Simulation

This project is available for simulation through two methods:

  • Wokwi project
  • Wokwi VS Code extension:
    1. Press F1, select Wokwi: Select Config File, and choose intro/hardware-check/wokwi.toml.
    2. Build your project.
    3. Press F1 again and select Wokwi: Start Simulator.

Troubleshooting

Build Errors

error[E0463]: can't find crate for `core`
= note: the `riscv32imc-esp-espidf` target may not be installed

You're trying to build with a stable Rust - you need to use nightly. this error message is slightly misleading - this target cannot be installed. It needs to be built from source, using build-std, which is a feature available on nightly only.

error: cannot find macro `llvm_asm` in this scope

You're using an incompatible version of nightly - configure a suitable one using rust-toolchain.toml or cargo override.

CMake Error at .../Modules/CMakeDetermineSystem.cmake:129 (message):

Your Espressif toolchain installation might be damaged. Delete it and rerun the build to trigger a fresh download:

rm -rf ~/.espressif

On Windows, delete %USERPROFILE%\.espressif folder.

Serial port: /dev/tty.usbserial-110
Connecting...

Unable to connect, retrying with extra delay...
Unable to connect, retrying with default delay...
Unable to connect, retrying with extra delay...
Error: espflash::connection_failed

× Error while connecting to device
╰─▶ Failed to connect to the device
help: Ensure that the device is connected and the reset and boot pins are not being held down

The board isn't accessible with a USB-C cable. A typical connection error looks like this:

Workarounds:

  1. Press and hold boot button on the board, start flash command, release boot button after flashing process starts
  2. Use a hub.

Source.