Week 4 - Embedded Programming

Group Assignment

Explore different microcontroller boards: Arduino, ESP8266, Xiao RP2040, and Teensy 4.0.
Compare their specifications, programming environments, and applications.
Document your work to the group work page and reflect on your individual page what you learned.

What is Embedded Programming?

Embedded programming involves creating system code for microcontrollers or microprocessors with specific hardware requirements. Unlike general-purpose computing, embedded systems are designed for dedicated functions with constraints on power, memory, and processing capabilities. These systems form the foundation of IoT devices, consumer electronics, and industrial applications.

Applications of Embedded Programming

During our research, we identified several key industries where embedded systems are prevalent:

• Industrial Automation: Machine control and production monitoring
• Consumer Electronics: Digital cameras, washing machines, smart TVs
• Internet of Things (IoT): Smart home appliances and connected devices
• Automotive Systems: Airbags, ABS brakes, engine control units
• Medical Equipment: Ventilators, insulin pumps, heart rate monitors

About Microcontrollers

A microcontroller is a compact integrated circuit designed to govern specific operations in an embedded system. It combines a CPU, memory (RAM, ROM, Flash), and I/O peripherals on a single chip. Their low power consumption and real-time processing capabilities make them ideal for various applications from consumer electronics to IoT devices.

Microcontroller Comparison

1. AVR Microcontrollers

AVR microcontrollers are based on RISC architecture and ideal for beginners. They're popular in Arduino boards, making them accessible for learning. Their low power consumption and simple programming model make them a great starting point for embedded systems development.

2. ARM Microcontrollers

ARM microcontrollers are known for scalability and power efficiency. They're widely used across industries from mobile to automotive. The Cortex-M family offers excellent performance for embedded applications. While they have a higher learning curve, they provide more powerful capabilities.

3. ESP8266 WiFi Microcontrollers

Built-in WiFi capabilities make these perfect for IoT and connected device projects. They have excellent community support and extensive libraries. ESP8266 offers a good balance of performance and ease of use, making it ideal for wireless applications.

4. STM32 Microcontroller

Based on ARM Cortex-M cores with industrial-grade performance. They feature multiple peripherals and a rich feature set. STM32 microcontrollers are used in demanding applications like medical and automotive systems. They have strong support from the manufacturer with comprehensive development tools.

Toolchains and Development Workflows

The key instruments and procedures required for embedded system development are the subject of research on toolchains and development workflows. A compiler, assembler, linker, debugger, and integrated development environment (IDE) comprise a toolchain that facilitates the efficient writing, compilation, and debugging of code. Different toolchains are used by different microcontrollers, including AVR, ARM, ESP8266 WiFi, and STM32, to guarantee the seamless creation and operation of embedded applications. A clear workflow increases productivity, lowers errors, and boosts system performance as a whole.

Toolchain Components

• Compiler: Transforms high-level code (C, C++) into machine code. Examples include GCC, Clang, IAR, and Keil.
• Assembler: Converts assembly language into binary instructions. Common assemblers include GNU Assembler and NASM.
• Linker: Combines compiled code and libraries to construct an executable. Examples include GNU LD and Keil Linker.
• Debugger: Enables step-by-step execution for troubleshooting. Popular debuggers include GDB, OpenOCD, and J-Link Debugger.
• Integrated Development Environment (IDE): Provides a complete development environment. Examples include VS Code, Eclipse, Keil, STM32CubeIDE, and Arduino IDE.

Development Workflow

1. Requirement Analysis: Select the appropriate hardware and define system objectives.
2. Code Development: Write embedded code using C, C++, or Assembly.
3. Compilation & Linking: Utilize the toolchain to convert source code into machine code.
4. Flashing to Target: Use a programmer or debugger to upload the compiled application onto the microcontroller.
5. Testing & Debugging: Employ tools like Serial Monitor, JTAG, or SWD for real-time debugging.
6. Optimization: Enhance power efficiency, minimize memory usage, and improve overall performance.
7. Maintenance & Deployment: Finalize and install the firmware on operational devices.

Example Toolchain for Microcontrollers

Which Tools Were Easier to Use?

Hands-On Experience with Different Platforms

Arduino UNO & Arduino Nano

We are using the Arduino UNO and Arduino Nano for microcontroller programming. These boards are easy to use and beginner-friendly. We are testing them for LED control, motor driving and sensor interfacing using the Arduino IDE. Their simplicity makes them ideal for learning digital and analog I/O, PWM and serial communication.

Arduino UNO

void setup() {
    pinMode(13, OUTPUT);
}

void loop() {
    digitalWrite(13, HIGH);
    delay(1000);
    digitalWrite(13, LOW);
    delay(1000);
}
            

Arduino Nano

void setup() {
    pinMode(13, OUTPUT);
}

void loop() {
    digitalWrite(13, HIGH);
    delay(1000);
    digitalWrite(13, LOW);
    delay(1000);
}
            

ESP8266 WiFi

We explored the ESP8266, which offers built-in WiFi capabilities ideal for IoT applications.

void setup() {
    pinMode(2, OUTPUT);
}

void loop() {
    digitalWrite(2, HIGH);
    delay(1000);
    digitalWrite(2, LOW);
    delay(1000);
}
            

Xiao RP2040

We researched the Xiao RP2040, which uses the Raspberry Pi RP2040 microcontroller with a compact form factor.

void setup() {
  pinMode(PIN_LED, OUTPUT);
}

void loop() {
  digitalWrite(PIN_LED, HIGH);
  delay(1000);
  digitalWrite(PIN_LED, LOW);
  delay(1000);
}
            

Teensy 4.0

We also explored the Teensy 4.0 platform, which is known for its high performance and small form factor.

Key Features:
Extremely fast 600 MHz ARM Cortex-M7 processor
Small form factor for compact projects
Compatible with Arduino IDE via Teensyduino
Extensive I/O capabilities with 40 digital pins
High-quality audio processing capabilities

Board Comparison for Fab Academy Applications