Pico W Blink Example

This is a simple example project for the Raspberry Pi Pico W that demonstrates:

• Basic GPIO control
• WiFi connectivity
• LED blinking
• USB serial output
• Interactive CLI interface

Prerequisites

• Docker or Podman installed on your system
• ARM GCC toolchain installed on your system
• picotool installed on your host system (not in container)

Building the Project

1. Build, create and start the container (only needed first time):

   ./p.sh bootstrap

   Replace /absolute/path/to/your/project with the full path to your project directory.

2. To access the container's shell:

   ./p.sh shell

3. To build the app inside the container

   ./p.sh build
   ./build.sh

Managing the Container

• To stop the container:

  podman stop pico-w-builder

• To start the container again:

  podman start pico-w-builder

• To remove the container (if you need to recreate it):

  podman rm pico-w-builder

Programming the Pico W

The build process creates a UF2 file in the build directory. To program your Pico W:

1. Make sure picotool is installed on your host system (not in the container)
2. Connect your Pico W to your computer via USB
3. Run the following command from your project directory:

   picotool load build/picowbase.elf

If you need to reboot the Pico W into bootloader mode:

picotool reboot -f -u

Using the CLI Interface

After programming, the Pico W will provide a command-line interface over USB serial. To access it:

On macOS:

1. Find the correct serial port:

   ls /dev/tty.usbmodem*
   ls /dev/cu.usbmodem*

2. Connect using one of these methods:

   a. Using screen:

   screen /dev/tty.usbmodem* 115200

   To exit screen: Press Ctrl-A followed by Ctrl-\ and confirm with y

   b. Using Serial (Mac App Store):

   • Open Serial
   • Select the port from the dropdown
   • Set baud rate to 115200
   • Click "Open"

   c. Using CoolTerm:

   • Download from http://freeware.the-meiers.org/
   • Open CoolTerm
   • Click "Options" and select the port
   • Set baud rate to 115200
   • Click "Connect"

On Linux:

1. Connect using screen:

   screen /dev/ttyACM0 115200

   To exit screen: Press Ctrl-A followed by Ctrl-\ and confirm with y

On Windows:

1. Use a terminal program like PuTTY or MobaXterm
2. Select the COM port assigned to the Pico W
3. Set baud rate to 115200

Available commands:

• help - Show available commands
• led on - Turn the LED on
• led off - Turn the LED off
• status - Show system status
• clear - Clear the screen
• exit - Enter bootloader mode for programming

Project Structure

• main.cpp - Main application code
• CMakeLists.txt - CMake build configuration
• build.sh - Build script
• lwipopts.h - lwIP configuration for WiFi
• Dockerfile - Container build configuration

Features

• Blinks the onboard LED
• Connects to WiFi
• Outputs status messages via USB serial
• Uses C++20 standard
• Supports programming without disconnecting USB cable
• Interactive CLI interface over USB serial

Troubleshooting

If you encounter any issues:

1. Make sure your Pico W is properly connected
2. Verify that picotool is installed and accessible from your host system
3. Check that the container has access to your project directory
4. Ensure you have the correct permissions to access the USB device
5. If the container isn't working properly, try removing and recreating it:

   podman rm pico-w-builder
   # Then follow the "Building the Project" steps again

6. If you can't access the CLI:
   • Check that the USB serial port is available
   • Try a different USB cable
   • Verify the baud rate is set to 115200
   • Try resetting the Pico W
   • On macOS, make sure you're using the correct port name (tty.usbmodem*)
   • Try a different terminal program if screen doesn't work

License

This project is licensed under the MIT License - see the LICENSE file for details.