PicoSDKandFreeRtos

Minimal Raspberry Pi Pico 2 (RP2350) project running FreeRTOS, plus a small .NET host tool to measure USB-CDC round-trip latency.

Firmware

The firmware exposes a simple ping protocol over USB-CDC. The host sends:

<id>:ping\n

and the Pico replies:

<id>:PONG!\n

Build & flash

Open the folder in VS Code with the Raspberry Pi Pico extension, then:

1. If not prompted directly: Command Palette -> Raspberry Pi Pico: Import Pico Project
2. Command Palette -> Raspberry Pi Pico: Run Pico Project (USB)

Required tooling (auto-installed by the extension):

• Pico SDK 2.2.0
• ARM GCC toolchain 14_2_Rel1
• picotool 2.2.0-a4
• Ninja, CMake

Host tool: response_tester.cs

A .NET 10 file-based app that bursts ping commands over the serial port and prints per-command and average round-trip latency.

Run

Requires .NET 10 SDK.

dotnet response_tester.cs

Adjust portName (default COM30) inside the file if needed.

Troubleshooting

Raspberry Pi Pico: Run Pico Project (USB) not working

• try Raspberry Pi Pico: Compile Pico Project
• hold BOOTSEL while connecting the Pico
• a new drive should be mountable
• move the *.uf2 file from ./build onto the new drive

COM-Port

• On Windows the Pico typically appears as COMx (check Device Manager).
• On Linux it appears as /dev/ttyACM0 (or ACM1, ...).
• On macOS it appears as /dev/tty.usbmodem* or /dev/cu.usbmodem*.
• Update portName in response_tester.cs accordingly.