ESP32 vs ESP8266: Key Differences Explained

This article compares the ESP32 and ESP8266 Wi-Fi boards, highlighting the key differences between them. We’ll explore the features of each board, including their similarities and distinctions, to help you choose the right one for your project.

What is ESP8266?

The ESP8266EX is a system-on-a-chip (SoC) that integrates a Wi-Fi radio, a 32-bit processor, and on-chip SRAM. It’s designed for Wi-Fi networking applications and can be used either as a standalone application or as a slave to a host microcontroller. The ESP8266EX includes antenna switches, a power amplifier, an RF balun, an LNA, filters, and power management units. It supports IEEE 802.11 b/g/n Wi-Fi standards.

ESP8266 is suitable for various applications, including:

• Home appliances
• Home automation
• Smart plugs
• IP cameras
• Sensor networks
• Wearable electronics
• Security ID tags
• Wi-Fi location-aware devices

The following figure illustrates the pin layout for the ESP8266’s 32-pin QFN package.

Here are some key features of the ESP8266, as depicted in its block diagram:

• CPU: Tensilica L106 32-bit RISC processor, with a maximum clock speed of 160 MHz. It includes interfaces like iBus (for programmable RAM/ROM interface), dBus (Data RAM interface), and AHB.
• Memory: The SoC integrates a memory controller and memory units (SRAM and ROM). There is no programmable ROM, so user programs are stored in external SPI flash memory.
• Clock: Used to drive both Tx and Rx mixers. The clock is generated using an internal or external crystal, ranging from 24 MHz to 52 MHz.
• Radio: Operates at 2.4 GHz frequency.
• Wi-Fi: Supports TCP/IP and the full WLAN MAC protocol as per IEEE 802.11 b/g/n. Supports STBC 2x1.
• Power Management: Supports various power modes, including active mode, modem sleep mode, light sleep mode, and deep sleep mode.
• BLE: Unlike the ESP32, the ESP8266 does not support Bluetooth.
• Interfaces: Supports 17 GPIOs, one slave SDIO (Secure Digital Input/Output), 2 SPIs (One general Slave/Master SPI, One general Slave HSPI), one I2C interface, one I2S, four PWM output interfaces, and two UART interfaces.
• IR Remote Control: One IR remote control interface is supported.
• ADC: A 10-bit precision SAR ADC is embedded on the SoC.

What is ESP32?

The ESP32 is designed for Wi-Fi and Bluetooth-based IoT applications. It integrates an antenna switch, a power amplifier, an LNA, filters, a balun, and power management modules. It supports Wi-Fi as per IEEE 802.11 b/g/n and Bluetooth as per Bluetooth V4.2 BR/EDR and BLE specifications.

Here are some key features of the ESP32 board:

• CPU: Xtensa ® single/dual-core 32-bit LX6 microprocessor
• Memory: 448 KB ROM, 520 KB SRAM
• Clocks: Internal 8 MHz oscillator, Internal RC oscillator, External 2 MHz to 60 MHz crystal oscillator
• Timers: Two timer groups, one RTC timer, and RTC watchdog.
• Peripheral Interfaces: 34 GPIOs, 4 SPIs, 2 I2S, 2 I2C, 3 UART, CAN 2.0, 1 host (SD/eMMC/SDIO), 1 slave (SDIO/SPI).
• ADC: 12-bit SAR ADC with up to 18 channels.
• DAC: 2 x 8-bit DAC
• Sensors: 10 x touch sensors, Hall sensor
• Infrared: IR (Tx/Rx)
• PWM: Motor PWM, LED PWM with up to 16 channels
• Security: 1024-bit OTP, up to 768 bits for customers

The figure above shows the top view of the ESP32 Pin Layout for the QFN 6x6 package.

Difference between ESP32 and ESP8266

The following table summarizes the similarities and differences between the ESP32 and ESP8266 boards.