ESP32: Intro

ESP32 + Python: From Microcontroller to IoT
Artical 01: ESP32

We've discussed about ESP32 in our previous artical on introduction. In this artical, we're focusing on ESP32 features to help our IoT projects

If you have used an Arduino board, you've probebly know that the need of extra modules when it comes to wireless communications. The especiallty of these ESP32 boards are the inbuilt WiFi and Bluethooth features.

These allows the boards to connect to networks and communicate with computers, smartphones, servers, and other devices without requiring additional wireless hardware.

The ESP32 chip itself is quite small and isn't designed to be connected directly to sensors and other components by beginners. A development board usually places the ESP32 module on a larger PCB and provides GPIO pins, power connections, USB connectivity, buttons, and other useful features.

Much like Arduino Uno, Nano in Arduino family, the most popular ESP32 boards are:

1. ESP32 DevKit V1
   Probably one of the most popular ESP32 boards for beginners. It usually uses the ESP32-WROOM-32 module and provides easy access to many GPIO pins.

2. ESP32-WROOM-32 DevKit
   A very common development-board design based on Espressif's ESP32-WROOM-32 module. It's widely used for learning, prototyping, sensors, and IoT projects.

3. ESP32-C3 SuperMini
   A very small and inexpensive board based on the ESP32-C3. It's useful when you want a compact project while still having Wi-Fi and Bluetooth Low Energy.

4. ESP32-S3 DevKitC
   A development board based on the ESP32-S3, which provides more modern features and is particularly interesting for applications involving USB and AI/edge-processing workloads.

5. NodeMCU-32S / ESP32 NodeMCU
   Another popular development-board style used in many tutorials and hobby projects.

Board	Best for
ESP32 DevKit V1	Beginners & general projects
ESP32-C3 SuperMini	Small/compact projects
ESP32-S3 DevKitC	More advanced projects

Here is a detailed table with the basics to know:

Feature	ESP32 DevKit V1	ESP32-WROOM-32 DevKit	ESP32-C3 SuperMini	ESP32-S3 DevKitC	NodeMCU-32S
Main chip	ESP32	ESP32	ESP32-C3	ESP32-S3	ESP32
CPU	Dual-core Xtensa LX6	Dual-core Xtensa LX6	Single-core RISC-V	Dual-core Xtensa LX7	Dual-core Xtensa LX6
Max clock	240 MHz	240 MHz	160 MHz	240 MHz	240 MHz
GPIOs on chip	Up to 34	Up to 34	Up to 22	Up to 45	Up to 34
Typical exposed GPIOs	~30–32	~30–32	~11–13	Depends on variant	~30
PWM	16 channels	16 channels	6 channels	8 channels	16 channels
Wi-Fi	2.4 GHz 802.11 b/g/n	2.4 GHz 802.11 b/g/n	2.4 GHz 802.11 b/g/n	2.4 GHz 802.11 b/g/n	2.4 GHz 802.11 b/g/n
Bluetooth	Classic + BLE	Classic + BLE	Bluetooth 5 LE	Bluetooth 5 LE	Classic + BLE
ADC	12-bit	12-bit	12-bit	12-bit	12-bit
DAC	2 channels	2 channels	❌ No	❌ No	2 channels
Capacitive touch	✅ Yes	✅ Yes	❌ No	✅ Yes	✅ Yes
Native USB	❌ No	❌ No	✅ Yes	✅ Yes	❌ No
USB connection	Usually USB-to-UART	Usually USB-to-UART	USB	USB	Usually USB-to-UART
Flash	Usually 4 MB	Usually 4 MB	Usually 4 MB	Typically 4–8 MB*	Usually 4 MB
PSRAM	❌ Usually no	❌ Usually no	❌ No	Available on some variants	❌ Usually no
Approx. board size	~55 × 28 mm	~55 × 28 mm	~22 × 18 mm	~50 × 25 mm*	~55 × 25 mm
Main advantage	Beginner-friendly & versatile	Mature ESP32 platform	Tiny & low-cost	Advanced processing & USB	Popular alternative ESP32 board
Best for	General IoT projects	General-purpose projects	Compact IoT projects	Advanced/AI/USB projects	General electronics & IoT

With these knowlegde, now you can choose an ESP32 board according to your project.

Usually a dev board(development board) contain these things

Part	Provived feature
ESP32 microcontroller/module	the main processing unit
GPIO pins	to connect sensors, LEDs, motors, displays, etc.
USB port	to programme the board and to often providing power
USB-to-Serial chip	allows your computer to communicate with boards that don't have native USB
Boot/EN buttons	useful for programming and resetting the board
Voltage regulator	converts the input voltage to the voltage required by the ESP32
Power pins	provide connections such as 3.3 V and GND

Why are development boards useful?
Development boards make experimenting with the ESP32 much easier. Instead of designing a circuit around the bare ESP32 chip, you can connect components directly to the board using jumper wires or a breadboard.

This makes development boards particularly useful for learning,
prototyping, IoT projects, robotics, and hardware-software experiments.

ESP32 communication Interfaces
Wired
ESP32 board supports 5 types of communication interfaces.

Interface	Type	Main purpose	Common uses	Key feature
UART	Wired / Serial	Point-to-point serial communication	GPS modules, computers, other microcontrollers, Python	Simple and doesn't require a clock line
I²C	Wired / Serial	Communication with multiple peripherals	OLEDs, LCDs, sensors, RTC modules	Uses only 2 signal lines (SDA & SCL)
SPI	Wired / Serial	High-speed peripheral communication	SD cards, TFT displays, memory, sensors	Faster than I²C in many applications
I²S	Wired / Serial	Digital audio communication	Digital microphones, speakers, audio codecs	Designed specifically for digital audio
CAN/TWAI	Wired / Bus	Reliable communication between multiple devices	Automotive systems, robotics, industrial control	Reliable and resistant to electrical noise

Wireless
ESP32 has 3 main wireless communication methods. ESP32 consists of a unique special wireless technology called ESP-NOW, granting you the ability to send data between ESP32 boards.

Technology	Type	Main purpose	Common uses	Key feature
Wi-Fi 📶	Wireless / Network	Network and internet communication	IoT, web servers, APIs, MQTT, Python	Can connect the ESP32 to networks and the internet
Bluetooth Classic 🔵	Wireless	Continuous device-to-device communication	Computers, phones, peripherals, audio	Available on some ESP32 variants
Bluetooth Low Energy (BLE) 🔵	Wireless	Low-power wireless communication	Sensors, wearables, beacons, smart devices	Designed for low power consumption
ESP-NOW 📡	Wireless	Direct ESP-to-ESP communication	Remote controls, wireless sensors, IoT	Doesn't require a traditional Wi-Fi router

These are just a little bit of inf about ESP32 dev boards. I hope this artical was useful with the given information. I hope to discuss about wireless communications in my next article.

Seeee you with wireless communication!

• Written By Janada Pelahara