# PicoSDKandFreeRtos

Minimal Raspberry Pi Pico 2 (RP2350) project running FreeRTOS to show task and queue creation / handling, task signaling, plus a small
.NET 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

## 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.

```bash
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.