Embedded Programming (Full Documentation)

Group Work (Grace & Carmencita)

Carmencita and I worked together on the group assignment, testing and comparing two embedded development workflows using real hardware (XIAO RP2040 and XIAO ESP32-C3). We documented our process, problem-solving, and results as a team.

For more details, visit our group documentation: 🔗 View group documentation

This week was also full of challenges. We were able to meet virtually with Professor Roberto from the node, who provided us with clearer guidance on the topic we were going to address during the week. Thanks to his orientation, we understood that the work was divided into a group component and an individual component, which required better organization and task distribution. Later, we met first virtually and then in person at the Fab Lab UNI to organize ourselves into small groups. This allowed us to develop the group component more efficiently, share ideas, and compare the work done, enriching the collective learning experience. Personally, I consider these topics challenging because they are new to me; however, I see them as a challenge that motivates me to continue learning. The most important thing has been to maintain a proactive attitude, looking for additional information and supporting each other within our group node to achieve our proposed goals.

Assignment Requirements

Group assignment
Demonstrate and compare the toolchains and development workflows for available embedded architectures
Document your work on the group work page and reflect on your individual page what you learned

Individual assignment
Browse through the datasheet for a microcontroller
Write and test a program for an embedded system using a microcontroller to interact (with local input &/or output devices) and communicate (with remote wired or wireless connections)

Progress Status

This is for reporting progress (not for visitors to click).

• Group work: Done - Group page link + notes added.
• Press-fit kit: Done - Missing final photos and conclusions.
• Downloads: Done - Upload .zip with source files.

Learning Outcomes

Implement programming protocols.

Have you answered these questions?

• Linked to the group assignment page: Yes
• Browsed and documented specific information from a microcontroller's datasheet: Yes
• Programmed a board to interact and communicate: Yes
• Described the programming process(es) used: Yes
• Includes your source code: Yes
• Included 'hero shot(s)': Yes

Introduction to Embedded Programming

This week was also full of challenges. We were able to meet virtually with Teacher Roberto, from the node, who gave us clearer guidance on the topic we had to address during the week. Thanks to his orientation we understood that the work was divided into a group part and an individual part, which implied a better organization and distribution of tasks.

Group Work

During week 4, which focused on embedded programming, my colleague Grace Schwan and the team organized to demonstrate and compare toolchains and development workflows across different microcontroller families. To better distribute the workload, each team member focused on a specific microcontroller.

In my case, I documented the operating and development environment of the ESP32-C3, while my colleague worked with the RP2040. Subsequently, we shared our findings with the team to analyze and compare them with other selected architectures, which allowed us to identify similarities, differences, and advantages of each platform.

1) Comparison of other architectures (Repeated Group Data)

For this comparison, we used four different families (XIAO form factor + one "minimal" ARM option):

• RP2040 (ARM Cortex-M0+ dual-core, 32-bit)
• ESP32-C3 (RISC-V, 32-bit, Wi-Fi/BLE)
• ESP32-S3 (Xtensa LX7 dual-core, 32-bit, Wi-Fi/BLE)
• ATSAMD11 (sometimes written "ATAMD11") (ARM Cortex-M0+, 32-bit)

[Editor's Note: The hardware comparison tables and analysis for RP2040, ESP32-C3, ESP32-S3, and ATSAMD11 are replicated here in the original document as part of the individual reflections. They confirm identical specs: 32-bit architecture, max clocks up to 240MHz for S3, and identical toolchain workflows matching the group consensus.]

Conclusions and practical comparison

• RP2040: It is well balanced: it has dual-core processing, good speed (up to 133 MHz) and enough memory (264 KB SRAM + 2 MB Flash) for medium projects. It is ideal for local control (LED, buttons, sensors, PWM, ADC) and fast development with Arduino or MicroPython.
• ESP32-C3: Is a good choice when wireless connectivity is required, as it includes Wi-Fi and Bluetooth (BLE). It is strong enough for basic IoT applications, and its main advantage is the ability to connect to a network or a phone. The workflow usually includes network setup (Wi-Fi credentials or BLE services).
• ESP32-S3: Is the most powerful option: it offers higher speed and significantly more available memory on the board (Large Flash + PSRAM). This is useful for heavier tasks, larger libraries or advanced features, while maintaining Wi-Fi/BLE connectivity.
• ATSAMD11: Is the most basic and limited in terms of resources (lower speed and memory). However, it is very useful for learning because it encourages writing efficient firmware and often involves a more "technical" workflow using ARM tools and SWD debugging. It is a good option to demonstrate a workflow other than simply uploading via USB.

Group Assignment Conclusion – Microcontroller Comparison

In this group task we compared, through actual practice, how these microcontrollers are programmed and how capable they are: XIAO RP2040, XIAO ESP32-C3, XIAO ESP32-S3, and ATSAMD11. We learned that it is not just about how powerful a chip is, but also how easy it is to program, what tools it uses and how fast you can test changes.

In summary, teamwork helped us compare tools and workflows and choose the right microcontroller based on project requirements.

Rocio and David's Group

For the Embedded Programming week, Rocio and I teamed up via Zoom to compare various development workflows. We split the tasks by choosing different microcontrollers to work on. I took charge of the RP2040 and, after documenting my process, shared the data with her to evaluate the differences between our selected architectures

In this section, I’m presenting a head-to-head comparison between two powerhouse microcontrollers: the Seeed Studio XIAO RP2040 and the ESP32-C3. Although they share a small form factor, their design approaches are worlds apart. After a Zoom session with my teammate Rocio, we organized the following structure to demonstrate and compare their development workflows:

1. Architecture Comparison

2. Toolchains (Development Environment)

The toolchain is the set of tools (compiler, linker, debugger) used to turn your code into a binary the chip can understand.

Key Points:

• The RP2040 Ecosystem is highly portable. Because it uses the ARM standard, many developers find the transition from other chips (like STM32) very easy. The UF2 bootloader is its "secret weapon" for group projects because it removes the need for special drivers to upload code.
• The ESP32-C3 Ecosystem is more specialized but powerful. It is essentially a "system-on-a-chip" designed to run a multitasking OS (FreeRTOS) by default. This makes the toolchain slightly heavier but allows for complex features like background Wi-Fi management.

3. Development Workflows

Workflow Analysis:

• The RP2040 Workflow is superior for rapid prototyping and educational settings. The fact that it behaves like a USB flash drive removes the "driver hell" often associated with microcontrollers. If your group wants to show a quick demo of changing code on the fly, this is the better choice.
• The ESP32-C3 Workflow is better for IoT Deployment. Its workflow assumes the device might not be plugged into a computer forever. The ability to manage memory partitions and perform OTA updates makes it the professional choice for connected devices.

Group Conclusions:

• Architecture & Power: While both share a compact footprint, the RP2040 offers a dual-core ARM Cortex-M0+ focused on high-speed hardware manipulation through its unique PIO (Programmable I/O). The ESP32-C3 uses a single-core RISC-V architecture designed specifically for the IoT era, integrating native Wi-Fi and Bluetooth.
• Connectivity & Scope: The ESP32-C3 is the clear winner for wireless projects, cloud integration, and remote monitoring. The RP2040 is better suited for standalone applications, high-performance local control, or scenarios where emulating specific hardware protocols is required.
• Toolchain & Debugging: The RP2040 follows traditional ARM standards, making it highly portable and easy to use with common compilers. However, the ESP32-C3 provides a more modern debugging experience with its built-in USB-JTAG, allowing for real-time code inspection without additional hardware.
• Development Workflow: The RP2040 excels in ease of use for beginners and rapid prototyping thanks to its "drag and drop" UF2 bootloader. Conversely, the ESP32-C3 offers a more robust industrial workflow, supporting multitasking via FreeRTOS and professional features like Over-the-Air (OTA) updates.
• Ecosystem & Community: The RP2040 benefits from the massive Raspberry Pi community and is the premier choice for Python-based embedded development. The ESP32-C3 leverages the mature Espressif ecosystem, which is the industry standard for low-cost, secure IoT deployment.

Jean Franco: Sub-Team Documentation

Class with Neil

During the theory class of week 04, we learned about the basic concepts of embedded programming and how microcontrollers work. We studied how code is loaded onto a board, what digital is and the function of analog pins, and how to control external components such as LEDs, buttons, sensors, and motors through programming.

This helped me understand how software can control physical hardware and how to structure simple programs, and how embedded systems interact with real-world inputs and outputs. It was an important step towards making my final project smart and interactive.

Group Task Summary

Before starting my individual work, we carried out several group tests to verify the laser cutting, engraving resistance, and cutting speed. These trials helped me better understand how the material reacts to different configurations and allowed me to choose the best parameters for my own design. And for this task we decided to carry out our task at the FAB LAB UNI.

Programming Protocol & Specifications

• RP2040: 133 MHz Clock, 2MB QSPI Flash, 1.8-5.5V Operating Voltage, programmable I/O (PIO), Compact 51x21mm dimensions.
• ESP32-S3: 240 MHz Clock, 8MB PSRAM, Bluetooth 5, 2.4GHz WiFi, Vector instructions for ML acceleration, Secure boot.

The Microcontroller Triad

With the goal of comparing performance, we carried out a basic test using the Blink program. The evaluated architectures were: ESP8266, ATMega328P, ATtiny44A. This experiment allows analyzing differences in architecture, processing capacity, operating voltage, and ease of programming using the Arduino IDE and C++.

Differences Identified:

• ESP8266: 32-bit architecture, includes built-in WiFi connectivity, operates at 3.3 V. Can present greater complexity in pin assignment due to its specific boot functions.
• ATMega328P: 8-bit AVR architecture. Very stable and widely used in Arduino Uno. Operates normally at 5 V. Features simple programming and high library compatibility.
• ATtiny44A: Also based on 8-bit AVR architecture. Designed for compact and low-power applications. Requires external programmers for code loading.