ESP series are very popular in makers' projects, ESP8266 and ESP32 are the most commonly used, We will talk about those 2 ESP series from Espressif, and some ESP8266 and ESP32 related products designed by Makerfabs.

1. ESP8266
In 2014, Espressif released a module called ESP8266, it was just intended as a WiFi module. Before ESP8266, the WiFi modules are expensive than $5, such as the widely used RN171. As the ESP8266 turns out, it made a great shake to the WiFi market, its price lower than $2, which makes it possible that more items can be connected to the internet directly at a much lower cost. 
The drawback of ESP8266 is that the ESP8266 does not provide any means to secure the code or the data it stores, which lead to risky, besides, as we Makerfabs testing, the power consumption is somewhat huge. 

2. ESP32
In 2016, the ESP32 was released. It has more GPIOs, ADCs and DAC. It is dual-core Lx6, integrated with Bluetooth 4.2, and important, it has hardware encryption and code signature, which is important for safety. In the first of its release, as Espressif’s production ability, it is in serious shortage on the market... Now it is stable and has been widely used in Makerfabs products.

In 2019, the ESP32-S2 was released. Compares to ESP32, it selects a different way: it is based on LX7 but single-core, it supports BLE5 and the USB OTG(which is essential for the CircuitPython), but as the main controller, seems it not so strong as the ESP32. Actually, it should be a transitional product from ESP32 to ESP32-S3. Which is about to release, by current files, it is based on dual-core 32-bit LX7, and also BLE integrated. 

In 2020 , the ESP32-s3 was released.The ESP32-S3 is a low-power MCU System-on-Chip (SOC) that supports 2.4 GHz Wi-Fi and low-power Bluetooth® LE dual-mode wireless communication. The chip integrates the Xtensa® 32-bit LX7 dual-core processor, ultra-low-power coprocessor, Wi-Fi baseband, Bluetooth baseband, RF module and peripherals.It could be the most strong processor of ESP series products by now. 

Also,the ESP32-S3 provides IoT devices with comprehensive security mechanisms and protection against various malicious attacks and threats. It supports Flash encryption based on the AES-XTS algorithm and secure boot based on the RSA algorithm; it has a digital signature and HMAC module for protecting private or symmetric keys from software attacks and ensuring device identity security. 

And In 2020, the ESP32-C3 was released, compares to other ESP modules, the most difference is that it is based on the RISC-V.

Than In 2021 , the ESP32-C6 was released.The ESP32-C6 has similar CPU, memory, and security features to the ESP32-C3. It features a 32-bit RISC-V single-core processor clocked at up to 160 MHz, 400 KB of internal SRAM, 384 KB of ROM, 46 GPIO ports, and support for IEEE 802.11ax standard 2.4 GHz Wi-Fi6.we think that it aims at the updated version of the ESP32-C3, target to consumer electronics& products.

3. ESP8266 and ESP32 Detailed Comparison:

  ESP8266 ESP32 ESP32-S2 ESP32-S3 ESP32-C3 ESP32-C6

Announcement Date

2014, August 2016, September 2019, September 2020, December 2020, November 2021, April
Main processor
Tensilica L106 32-bit (up to 160MHz) Tensilica Xtensa 32-bit LX6 (up to 240MHz) (optionally dual core) Tensilica Xtensa 32-bit LX7 (up to 240MHz) Tensilica Xtensa 32-bit LX7 dual core (up to 240MHz) RISC-V 32-bit (up to 160MHz) RISC-V 32-bit (up to 160MHz)
SRAM 160KB 520KB 320KB 512KB 400KB 400KB
ROM 0 448KB 128KB 384KB 384KB 384KB
Cache 32 KB instruction 64KB 8/16KB (configurable) ? 16KB ?
WiFi Wi-Fi 4 (only up to 72.2Mbps) Wi-Fi 4 Wi-Fi 4 Wi-Fi 4 Wi-Fi 4 Wi-Fi 6
Bluetooth x BLE 4.2 (upgrade to 5.0, with limitations) x BLE 5.0 BLE 5.0 BLE 5.0
Ethernet x x ? x ?
RTC memory 768B 16KB 16KB 16KB 8KB ?
PMU ? ?
ULP coprocessor x

Cryptographic Accelerator XSHA, RSA, AES, RNG, HMAC, Digital Signature SHA, RSA, AES, RNG SHA, RSA, AES, RNG, HMAC, Digital Signature SHA, RSA, AES, RNG, HMAC, Digital Signature SHA, RSA, AES, RNG, HMAC, Digital Signature SHA, RSA, AES, RNG, HMAC, Digital Signature
Secure boot X
Flash encryption X XTS-AES-128/256 XTS-AES-128 XTS-AES-128
SPI 2 4 4 ? 3 ?
I2C 1 2 2 ? 1 ?
I2S 1 2 1 ? 1 ?
GPIO 17 34 43 44 22 22
LED PWM 5 16 8 ? 6 ?
Pulse counter 0 8 4 ? 0 X
USB x x USB OTG 1.1 ? Serial/JTAG ?
ADC 1x 10-bit SAR 2x 12-bit SAR, up to 18 channels 2x 13-bit SAR, up to 20 channels ? 2x 12-bit SAR, up to 6 channels ?
DAC X 2x 8-bit 2x 8-bit ? X X
RMT 1x transmission + 1x reception 8x transmission/reception 4x transmission/reception ? 2x transmission + 2x reception ?
Timer 2x 23-bit 4x 64-bit 4x 64-bit ? 2x 54-bit + 1x 52-bit ?
Temperature Sensor ? ?
Hall Sensor X X ? X ?
Touch Sensor 0 10 14 ? X ?
  • All the MCUs have some sort of DMA. However, if this field is not checked, it means that the user hasn't the direct control

In the past years, Makerfabs have more than 100 products& projects with ESP series, either by our designed IoT products, or customers ODM projects, have rich experience in the R&D, components vendors, production, and testing:

3.1 ESP8266 Projects:
ESP8288 WiFi Shield for Arduino
MakePython ESP8266

3.5 ESP32-PICO-D4 Projects:
DC Motor for Home Assistant_GA36Y-555

If any projects designing& production requests about the ESP series, welcome to contact Makerfabs for assistance.