Week 11

Networking & Communications

• Group homework:
  • Send a message between two projects
  • Document your work on the group work page and reflect on what you learned on your individual page.
• Individual task:
  • Design, build, and connect wired or wireless nodes with network or bus addresses and local input and/or output devices.

Objective

Design and implement a communication system between two electronic nodes, integrating a self-developed board based on theXIAO ESP32-C3 microcontroller and an Arduino board, in order to establish data exchange through serial communication protocol.

The system seeks to transmit information from an input device, process it at the sending node and send it to a receiving node, which interprets the data and executes an action on an output device, thus validating a complete flow of communication in embedded systems.

GROUP ASSIGNMENT

Link:
https://fabacademy.org/2026/labs/lima/Weeks/Week11/Week11.html

Sending messages between two projects

During the group assignment, communication between two independent electronic systems was implemented, allowing the sending and receiving of data through serial communication protocol.

🔹Configuration:

• Sending Node (Microcontroller Board)
• Receiving Node (Microcontroller Board)
• Serial Communication (TX/RX)

🔹How it works:

1. A node generates a digital message (data)
2. The message is transmitted through the serial channel
3. The receiving node receives the information
4. The system interprets the message and executes an action (e.g. LED activation)

🔹Technical validation:

• Correct data transmission was verified
• Synchronization between sender and receiver was verified
• The integrity of the received message was validated

This exercise allowed us to understand:

• Real-time data synchronization
• Principles of serial transmission
• Importance of communication settings (baud rate, TX/RX pins)

Learning Achieved

Through the group assignment, I learned how communication between two electronic systems is established using serial protocols. I understood the importance of configuring communication parameters such as baud rate, TX/RX connections, and data synchronization to ensure reliable message transmission. This activity helped me understand how embedded devices exchange information in real time and how communication integrity is essential for coordinated system operation.

Cross-device communication

INDIVIDUAL ASSIGNMENT

WiFi Communication System with XIAO ESP32-C3

This week a basic wireless communication system was developed using the custom board based on theXIAO ESP32-C3 and an interface created withRemoteXY.

The main objective was to establish communication between a mobile device and the custom PCB using WiFi, managing to display a personalized image of a flower on the OLED screen.

For this activity, the PCB previously designed during the Electronic Production week was reused, demonstrating continuity and integration between assignments.

Objective of the Activity

Design and connect a wireless system using theXIAO ESP32-C3 microcontroller to communicate with a mobile device and display visual information on an OLED screen.

My Process:

System Architecture

The system is composed of:

Node 1 – Mobile Device

• RemoteXY App
• WiFi Communication Interface

Node 2 – Embedded System

• Custom PCB
• XIAO ESP32-C3
• OLED Display

Communication was done using the XIAO ESP32-C3's built-in WiFi connectivity.

Project Development

Platform used

The following platform was used:

RemoteXY Editor

This platform made it possible to:

• Create the mobile interface
  ✔ Set up the WiFi connection
  ✔ Automatically generate the communication code

RemoteXY Configuration

Configured parameters

Communication was established through the WiFi network created by the system.

Hardware Integration

Components used

System Connection

The OLED display was connected via I2C communication to the XIAO ESP32-C3.

Main connections

Programming

The programming was done inArduino IDE using:

• RemoteXY Bookcase
• Adafruit Bookstore SSD1306
• Adafruit GFX Bookcase

Official Repository:

RemoteXY Arduino Library

How the System Works

When the system establishes a WiFi connection:

• The XIAO ESP32-C3 processes communication
  ✔ The OLED screen is activated
  ✔ A custom image of a flower is displayed on the OLED

This shows:

• Wireless communication
• Hardware-software integration
• Real-time graphical display

Communication Protocols Used

• WiFi
  ✔ I2C Communication for OLED

Problems Encountered

Problem 1 – OLED Not Showing Image

Solution

• I2C Address Correction
• Adjusting Libraries

Problem 2 – Unstable WiFi connection

Solution

• Network parameter reconfiguration
• System reboot

📋 Check-off List

1. Linked to the group assignment page?

Yes. The link of the week of Networks and Communications was included.

2. Did you document your project and what you learned about communication protocols?

Yes. Serial communication and WiFi between nodes was explained using the PCB with XIAO ESP32-C3, RemoteXY and OLED screen via I2C.

3. Did you explain the programming process used?

Yes. The use of Arduino IDE, RemoteXY libraries, as well as WiFi configuration and I2C communication were documented.

4. Did you document that addressing works?

Yes. The communication between sender and receiver, TX/RX configuration, WiFi and I2C direction of the OLED was validated.

5. Did you describe problems and solutions? Yes.

• Pictureless OLED → I2C direction correction and libraries.
• WiFi unstable → network reconfiguration and system reboot.

6. Did you include design files and source code?

Yes. The previously designed PCB, code in Arduino IDE, and RemoteXY configuration were included.

7. Does it include a HERO SHOT?

Yes. The PCB was shown working with WiFi communication and OLED screen display.

❓ Frequently Asked Questions

1. What does "two projects" mean in group homework?

Answer:
In my case, I implemented it as the communication between two real nodes of the system. I used my board designed with XIAO ESP32-C3 as the emitter node and another board (Arduino or receiver system) as a second project. A message was sent between the two by serial or wireless communication, which was interpreted to activate an action such as turning on an LED or updating an output.

2. Do I need to create a new board for this task?

Answer:
No. For this week I reused the PCB that I had already designed in previous works. This allowed me to focus solely on the communication part between nodes, without the need to manufacture new hardware.

3. Can we use Arduino/commercial boards for the individual task?

Answer:
Yes, as long as one of the plates is of your own design. In my implementation I used my XIAO ESP32-C3 based board along with an Arduino board or commercial modules as a communication support. This allowed to validate the interoperability between own and commercial hardware within the same system.

4. What is meant by network or bus address?

Answer:
I understood it as the identity of each node within the communication system. In my project this "address" was not a complex code, but the assignment of roles (sender and receiver) and the configuration of the communication channel (TX/RX or WiFi), ensuring that each device receives only the information that corresponds to it.

5. What does "original code" mean?

Answer:
In my case it was the code that I adapted and modified from examples of Arduino and RemoteXY. I adjusted it to integrate my PCB, OLED screen, and WiFi communication, making real functional changes like data display and sending messages between nodes.

6. What is a local interface?

Answer:
It is the point of direct interaction with the system. In my project it was the OLED screen connected to the PCB, where the information is displayed, and also the interface created in RemoteXY on the cell phone, which allowed me to interact with the system in real time.

7. Do I need to use more than one whiteboard/system for this task?

Answer:
Yes. In my implementation I used at least two systems: my board with XIAO ESP32-C3 as the main node and a second board or receiver system. This was necessary to demonstrate the actual communication between devices and validate the complete flow of data within the network.