Week 04 – Embedded Programming

Objective:

Demonstrate and compare the toolchains and development workflows for available embedded architectures.

Microcontrollers Analyzed:

• ESP32-S2 (Xtensa LX7 architecture)
• XIAO ESP32-C3 (RISC-V architecture)
• Arduino Nano (AVR ATmega328P architecture)

Embedded Architectures Comparison

Toolchains and Development Workflows Comparison

The ESP32 family allows advanced debugging using JTAG and FreeRTOS integration, while the Arduino Nano workflow is simpler but more limited in professional debugging tools.

Browsing the Datasheet

The datasheet of the ATmega328P (Arduino Nano) and ESP32-S2 was reviewed. Key sections analyzed:

• Pin configuration and GPIO mapping
• Memory organization (Flash, SRAM, EEPROM)
• ADC resolution and reference voltage
• Communication peripherals (UART, I2C, SPI)
• Power consumption modes

Understanding the datasheet allowed correct configuration of registers, communication interfaces, and peripheral usage.

Write and Test a Program (Input/Output Interaction)

A program was developed to:

• Read a push button (digital input)
• Control an LED (digital output)
• Send data through Serial communication (wired)
• Test wireless communication using WiFi (ESP32)

const int buttonPin = 4;
const int ledPin = 2;

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  int buttonState = digitalRead(buttonPin);

  if (buttonState == LOW) {
    digitalWrite(ledPin, HIGH);
    Serial.println("Button Pressed - LED ON");
  } else {
    digitalWrite(ledPin, LOW);
    Serial.println("Button Released - LED OFF");
  }

  delay(200);
}

The system successfully interacted with physical input (button), controlled an output (LED), and communicated through USB serial.

Communication Test (Wireless – ESP32)

Using ESP32 WiFi libraries, the board connected to a local network and transmitted status messages via TCP.

This demonstrates wireless embedded communication capability, which is not available on the Arduino Nano without additional modules.

Microcontroller: XIAO ESP32-C3

1. Installation of Arduino IDE (Step-by-Step)

Step 1 – Download Arduino IDE

Go to the official Arduino website and download the latest version for your operating system.

Step 2 – Install Arduino IDE

Run the installer and follow the installation wizard:

• Accept license agreement
• Select default components
• Complete installation

Step 3 – Install ESP32 Board Package

1. Open Arduino IDE
2. Go to File → Preferences
3. In “Additional Board Manager URLs” paste:

4. Go to Tools → Board → Boards Manager
5. Search for ESP32
6. Install "esp32 by Espressif Systems"

Step 4 – Select Board

Tools → Board → ESP32 Arduino → Select "XIAO_ESP32C3"

2. Simulation in Wokwi

Step 1 – Create Project

Go to wokwi.com and create a new ESP32-C3 project.

Step 2 – Add Components

3. Program Uploaded to XIAO ESP32-C3

Console Output + LED Control Code

    void setup() {
    Serial.begin(115200);
    pinMode(D8, OUTPUT);
    pinMode(D9, OUTPUT);
    pinMode(D10, OUTPUT);

    Serial.println("");
    Serial.println("Hello, XIAO ESP32-C3!");
    Serial.println("Welcome to Wokwi :-)");
    }

    void loop() {
    Serial.println("Red");
    digitalWrite(D8, HIGH);
    delay(300);
    digitalWrite(D8, LOW);

    Serial.println("Green");
    digitalWrite(D9, HIGH);
    delay(300);
    digitalWrite(D9, LOW);

    Serial.println("Blue");
    digitalWrite(D10, HIGH);
    delay(600);
    digitalWrite(D10, LOW);
    }
    
    

4. Serial Monitor Output

5. Final Physical Assembly on Protoboard

Hardware Components Used

6. Final Demonstration Video

7. Reflection

This practice demonstrates embedded programming fundamentals including GPIO configuration, serial communication, digital output control, simulation before physical implementation, testing workflow, and debugging.

The workflow followed: Simulation → Code Debugging → Serial Monitoring → Physical Assembly → Final Validation.

Extra Credit – Assemble the System

The embedded system was assembled on a breadboard including:

• Microcontroller board
• Push button with pull-up configuration
• Current limiting resistor (220Ω)
• LED indicator

The hardware assembly was tested and validated before final code deployment.

Extra Credit – Different Languages and Development Environments

Additional testing was performed using:

• PlatformIO (VS Code environment)
• ESP-IDF framework
• C/C++ standard Arduino framework

Differences observed:

• ESP-IDF provides deeper hardware control.
• PlatformIO improves project structure and debugging integration.
• Arduino IDE allows faster prototyping.

• ✔ Demonstrated and compared embedded toolchains
• ✔ Compared development workflows for different architectures
• ✔ Reviewed microcontroller datasheet
• ✔ Wrote and tested embedded program
• ✔ Interacted with input and output devices
• ✔ Implemented wired communication (Serial)
• ✔ Implemented wireless communication (WiFi ESP32)
• ✔ Assembled hardware system (extra credit)
• ✔ Tested different environments and frameworks (extra credit)