Objective
This project aims to create a device using a Raspberry Pi Pico W and a 16x2 LCD with RGB backlight. The device will receive 16-byte messages via UDP, scrolling up the LCD to add each new message on the bottom line.
Equipment
- Raspberry Pi Pico W - Adafruit Product ID 5526
- 16x2 LCD with RGB backlight - Adafruit Product ID 398
- Jumper wires
- Breadboard (optional for prototyping)
- Wi-Fi network access
Construction
Wiring the LCD to the Raspberry Pi Pico W
-
LCD Power and Ground:
- Connect the VSS pin of the LCD to GND on the Pico W.
- Connect the VDD or VCC to 3.3V or 5V on the Pico W (as per LCD's specification).
-
LCD Data Pins:
- Connect RS (Register Select) to GP17, E (Enable) to GP22, and D4 to D7 to GP18, GP19, GP20, and GP21 respectively on the Pico W.
-
Backlight:
- ...
Setting Up the Raspberry Pi Pico W
- Install CircuitPython on your Raspberry Pi Pico W.
- Add the necessary libraries (
wifi
,socketpool
,adafruit_character_lcd
) to the Pico W.
pico ... lcd GP17 -- 4 RS (Register Select) GP22 -- 6 E (Enable) GP18 -- 11 D4 GP19 -- 12 D5 GP20 -- 13 D6 GP21 -- 14 D7 5V -- 2 VDD GND -- 1 VSS GND -- 5 RW (Read/Write, Grounded for Write)
Code
Receiving UDP packets.
Testing
-
Initial Power-Up and LCD Check:
- After completing the wiring, power up your Raspberry Pi Pico W.
- Check if the LCD lights up and displays the initial message ("!!! Pico W !!!"). This confirms that the LCD is correctly powered and initialized.
-
Wi-Fi Connection Verification:
- Ensure that the Pico W successfully connects to your Wi-Fi network.
- The LCD should display the IP address of the Pico W, confirming successful network connection.
-
Sending Test UDP Packets:
- Use a computer or a mobile device on the same Wi-Fi network to send UDP packets to the Pico W.
- You can use network tools or scripting languages (like Python with the
socket
module) to send packets to the Pico W's IP address at the specified port (default 5000).
-
Observing LCD Updates:
- When the Pico W receives a UDP packet, observe the LCD to check if the message scrolls and displays correctly.
- The new message should appear at the bottom of the display, and the previous message should move up.
-
Debugging:
- If messages are not displayed as expected, check your network settings and confirm that UDP packets are being sent to the correct IP address and port.
- Revisit your code to ensure that the logic for receiving UDP packets and updating the LCD is correctly implemented.
-
Continuous Operation Test:
- To test the stability and continuous operation, send messages at regular intervals and observe the LCD over a longer period.
Conclusions
Upon completing this project, you have successfully built a device using a Raspberry Pi Pico W and a 16x2 LCD, capable of displaying messages received via UDP. This project not only demonstrates your ability to integrate various components - a microcontroller, LCD display, and networking - but also highlights your skills in software development with CircuitPython.
Achievements
- Hardware Integration: Successfully interfaced a Raspberry Pi Pico W with an LCD.
- Networking: Implemented UDP communication to receive real-time data.
- Software Development: Developed and debugged a CircuitPython program to control hardware based on network inputs.
Learnings
- Gained experience in handling LCD displays and understanding their communication protocols.
- Learned about network programming in CircuitPython, particularly working with UDP sockets.
- Improved problem-solving skills, especially in debugging hardware-software interactions.
Potential Enhancements
- Dynamic Backlight Control: If desired, implement PWM control for the LCD’s backlight to enable dynamic color changes.
- Advanced Message Handling: Implement features like message queuing, filtering, or formatting for better display management.
- Integration with IoT Platforms: Consider integrating with IoT platforms for more complex applications or remote message sending.