ESP32 Lab Notes — My First Experiments

Over the last weeks I started experimenting with ESP32 boards, embedded development, UART communication, and low-level hardware concepts.

This post documents my setup, troubleshooting sessions, lessons learned, and ideas for future projects.

Hardware Used

Boards

• ESP32-C3
• ESP32 SuperMini
• ESP32 Dev Boards
• HW-131 power module
• USB-C ESP32 boards with dual ports (USB and COM)

Accessories

• Breadboards
• USB-C cables
• Jumper wires
• Multimeter / tester
• External power supplies
• Mac Mini for development

Understanding the USB Ports

One of the first confusing things was discovering that some ESP32 boards expose two USB-C ports.

COM Port

Usually connected to:

• UART bridge
• flashing firmware
• serial monitor
• debugging logs

This is typically the port used by:

idf.py -p /dev/cu.wchusbserialXXXX monitor

USB Port

Usually connected directly to the ESP32 USB peripheral.

Can be used for:

• native USB
• HID devices
• keyboard/mouse emulation
• USB networking
• custom firmware features

Serial Communication & UART

The ESP32 serial monitor runs over UART.

Typical baud rate:

115200

This defines the speed of serial communication.

OSI Perspective

UART is mostly Layer 1 / Layer 2 adjacent:

• Physical signaling
• byte transport
• no routing
• no packet switching

Compared to:

ESP-IDF Setup

I experimented with Espressif’s official SDK:

• ESP-IDF
• idf.py
• esptool
• serial monitoring

Export Environment

Fish shell:

source ~/esp/esp-idf/export.fish

Common Commands

Monitor serial logs

idf.py -p /dev/cu.wchusbserialXXXX monitor

Detect chip

esptool chip-id

Flash firmware

idf.py flash

Troubleshooting Serial Detection

One major issue:

Found 0 serial ports...

Things checked:

• USB cable quality
• power-only cables
• USB permissions
• drivers
• rebooting the board
• disconnecting/reconnecting
• checking /dev/cu.*
• verifying CH340/WCH serial devices

Arduino IDE vs ESP-IDF

I tested both environments.

Arduino IDE

Pros:

• fast setup
• beginner friendly
• huge ecosystem

Cons:

• abstracts many low-level details
• harder to debug internals

ESP-IDF

Pros:

• official framework
• lower-level access
• RTOS integration
• production-grade tooling

Cons:

• steeper learning curve

Power Supply Lessons

I experimented with powering modules using:

• 12V 300mA adapters
• 12V 2A adapters

One module was damaged after using a larger supply.

Important lesson:

Voltage matters first

Current is available, not forced.

But:

• unstable supplies
• incorrect regulators
• wiring mistakes
• reverse polarity

can still destroy components.

Learning Electronics Basics

Topics explored:

Measuring Voltage

Using a tester/multimeter to:

• measure DC voltage
• identify polarity
• verify outputs

Identifying 220V Wires

Important concepts:

• phase/live
• neutral
• grounding

And understanding why reversing connections may still work electrically but can reduce safety.

ESP32 Project Ideas

Distributed Sensor Network

Small IoT infrastructure:

• multiple ESP32 publishers
• one central consumer
• MQTT messaging
• environmental sensors

BLE Tracker

Using BLE advertisements to:

• detect nearby devices
• estimate presence
• track movement patterns

WiFi Sniffer

Educational exploration of:

• WiFi beacons
• probe requests
• RSSI analysis

CAN Bus Experiments

Learning:

• SocketCAN
• candump
• cansend
• python-can

Potential use cases:

• automotive reverse engineering
• industrial protocols
• telemetry

RF & Wireless Curiosity

Topics I want to explore further:

• WiFi
• Bluetooth Low Energy
• NRF24
• CC1101
• RTL-SDR
• RF packet analysis

Comparisons:

ESP32 + AI

One interesting direction is combining ESP32 hardware with local AI systems.

Potential architecture:

ESP32 -> MQTT -> Local LLM -> Analysis Dashboard

Applications:

• sensor anomaly detection
• HTTP traffic correlation
• distributed telemetry
• smart home automation
• industrial monitoring

Future Experiments

Planned projects:

• BLE proximity detector
• ESP32 mesh networking
• MQTT infrastructure
• LoRa communication
• CAN bus dashboard
• SDR signal visualization
• custom PCB design
• low-power battery deployments

Final Thoughts

The ESP32 ecosystem is an excellent bridge between:

• software engineering
• networking
• embedded systems
• RF experimentation
• IoT infrastructure
• low-level debugging

Coming from backend/security engineering, working directly with hardware changes the perspective completely.

You stop thinking only in APIs and services and start thinking about:

• signals
• timing
• power
• buses
• protocols
• physical constraints

And that opens a completely different layer of computing.