Raspberry Pi Pico WiFi Hotspot Web Server

This MicroPython project creates a WiFi hotspot on the Raspberry Pi Pico and serves a web interface that allows you to control the built-in LED and read analog values.

Features

• WiFi Hotspot: Creates an access point named "PicoHotspot"
• Web Interface: Modern, responsive web interface accessible from any device
• LED Control: Toggle the built-in LED on/off via web interface
• Analog Reading: Read analog values from ADC pin and display on website
• Real-time Updates: See current LED status and latest ADC reading

Hardware Requirements

• Raspberry Pi Pico (or Pico W for WiFi capability)
• Micro USB cable for power and programming
• Optional: Analog sensor (potentiometer, light sensor, etc.) connected to GP26

Pin Connections

• Built-in LED: GP25 (automatically configured)
• ADC Input: GP26 (ADC0) - for analog readings

Setup Instructions

1. Install MicroPython on Pico

1. Download the latest MicroPython firmware for Raspberry Pi Pico from micropython.org
2. Hold the BOOTSEL button on the Pico while connecting it to your computer
3. The Pico will appear as a USB mass storage device
4. Copy the .uf2 firmware file to the Pico
5. The Pico will restart and run MicroPython

2. Upload the Code

1. Connect the Pico to your computer
2. Copy main.py to the Pico's file system
3. The Pico will automatically run main.py on boot

3. Connect to the Hotspot

1. Power on the Pico
2. Look for a WiFi network named "PicoHotspot"
3. Connect to it using password: 12345678
4. Open a web browser and navigate to: http://192.168.4.1

Usage

Web Interface

The web interface provides:

1. LED Control Button: Click to toggle the built-in LED on/off
2. Read Analog Button: Click to read the current analog value from GP26
3. Status Display: Shows current LED state and latest ADC reading

LED Control

• The LED button changes color based on current state (green = off, red = on)
• Click the button to toggle between ON and OFF states
• The built-in LED on the Pico will physically turn on/off

Analog Reading

• Connect an analog sensor (like a potentiometer) to GP26
• Click "Read Analog Value" to get the current reading
• Values range from 0 to 65535 (16-bit ADC)
• The reading is displayed prominently on the webpage

Code Structure

• main.py: Main program file containing all functionality
• WiFi hotspot creation and configuration
• Web server implementation
• HTML generation with embedded CSS
• HTTP request handling
• Hardware control (LED and ADC)

Customization

Change WiFi Settings

Edit these lines in main.py:

ap.config(essid='YourNetworkName', password='YourPassword', authmode=network.AUTH_WPA_WPA2_PSK)

Change ADC Pin

To use a different ADC pin, modify:

adc = ADC(26)  # Change 26 to your desired pin (26, 27, or 28)

Modify Web Interface

The HTML and CSS are embedded in the generate_html() function. You can customize the appearance by modifying the HTML string.

Troubleshooting

Pico Not Creating Hotspot

• Ensure you're using a Pico W (has WiFi capability)
• Check that MicroPython is properly installed
• Verify the code is uploaded as main.py

Can't Connect to Hotspot

• Make sure the Pico is powered on
• Check that the SSID "PicoHotspot" appears in your WiFi list
• Try the password: 12345678
• Some devices may take a moment to connect

Web Interface Not Loading

• Ensure you're connected to the PicoHotspot WiFi
• Try accessing http://192.168.4.1 in your browser
• Check the Pico's serial output for error messages

ADC Readings Not Working

• Verify your analog sensor is connected to GP26
• Check wiring connections
• Ensure the sensor is powered if required

Technical Details

• WiFi Mode: Access Point (AP) mode
• IP Address: 192.168.4.1 (default AP address)
• Port: 80 (HTTP)
• ADC Resolution: 16-bit (0-65535)
• Memory Management: Includes garbage collection to prevent memory issues

Security Notes

• The default WiFi password is simple for testing
• Change the password for production use
• The web interface has no authentication
• Consider adding security measures for sensitive applications

License

This project is open source and available under the MIT License.