Networking and communications

Group assignment:
Send a message between two projects
Document your work to the group work page and reflect on your individual page what you learned

Individual assignment: Design, build and connect wired or wireless node(s) with network or bus addresses and a local input and/or output devices

This project is part of our networking and communication assignment. It demonstrates how multiple microcontrollers can share data using serial communication while also providing user feedback from the Serial and visual output. The network is built on wired serial communication.
The connecting wire are Switched on the breadboard to allow multiple devices to connect on the network.

Programming Approach

Each component was tested separately before integrating into the final sketch. The code performs the following tasks:

Reads the commands from other micro-controller serial
Displays message on I2C LCD if it is a display command
Listens for RGB command from other micro-controller
Updates NeoPixel color based on received command

Addressing Method

Each board is given a unique ID (int id = 2;). to ensure only the intended recipient processes a message.
Messages follow the format COMMAND:R,G,B@ID (e.g., COLOR:255,0,0@2).
If the incoming ID matches the board’s ID, it processes the message based on the command to perform (COLOR to sets the NeoPixel color accordingly, DISPLAY to show message on LCD).

Challenges & Fixes

OLED compatibility issues – 1. OLED display not working – Switched to a 1602 I2C LCD after discovering OLED library compatibility issues with the XIAO RP2040.
Serial1 miswiring – corrected TX/RX pins
Sensor noise – added delays to stabilize readings and manually calibrated thresholds for rain detection.
I2C not displaying – Ensured correct wiring (TX/RX), used Serial1.begin(115200); and tested with basic echo script (Hello world)
downloaded from Randomnerdtutorials

Test display script

/*********
          Test display script
          *********/
          
          #include 
          
          // set the LCD number of columns and rows
          int lcdColumns = 16;
          int lcdRows = 2;
          
          // set LCD address, number of columns and rows
          // if you don't know your display address, run an I2C scanner sketch
          LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  
          
          void setup(){
            // initialize LCD
            lcd.init();
            // turn on LCD backlight                      
            lcd.backlight();
          }
          
          void loop(){
            // set cursor to first column, first row
            lcd.setCursor(0, 0);
            // print message
            lcd.print("Hello, World!");
            delay(1000);
            // clears the display to print new message
            lcd.clear();
            // set cursor to first column, second row
            lcd.setCursor(0,1);
            lcd.print("Hello, World!");
            delay(1000);
            lcd.clear(); 
          }

LCD (16x2) display

Below are the results from the serial commands.
Before commands

LCD display message

LED display color based on the command.

Serial message

Code file to test
Networking code