ESP8266
A breakthrough IoT chip. Major advantage: built-in Wi-Fi.
Wi-Fi modes:
- Station mode: connects to an existing Wi-Fi network
- Access point mode: creates its own Wi-Fi network
Features:
- 32-bit processor
- ~50 KB RAM
- ~32 KB ROM
- USB programming
- Low power operation
Soft Microcontroller
Unused modules can be disabled, reducing power consumption and interference.
ESP32
Improved version of the ESP8266.
Added features over ESP8266:
- Better Wi-Fi
- Bluetooth Low Energy (BLE)
- More memory
- ADC and DAC channels
- Infrared support
- CAN Bus support
Programming options: Arduino, Lua, MicroPython.
NodeMCU
Open-source IoT platform built on the ESP8266 (or ESP32) microcontroller.
Consists of two parts:
- Firmware
Open-source Lua runtime flashed onto the ESP chip. Exposes hardware peripherals as Lua modules. - Development board
PCB carrying the ESP module, a USB-to-Serial converter (CH340 or CP2102), voltage regulator, and reset/flash buttons.
The USB-to-Serial converter allows direct programming from a PC without an external programmer.
Primary language: Lua. Also supports MicroPython and Arduino C++ via alternative firmware.
ESPlorer
IDE designed for NodeMCU Lua development. Connects to the board over the serial port and provides:
- Script upload to the device filesystem
- Interactive Lua REPL (command-line evaluation)
- Serial monitor for output