Comparison for Espressif MCUs

A bunch of ESP8266 and ESP32-S2 modules. Figura 1: A bunch of ESP8266 and ESP32-S2 modules.

Recently Espressif has dramatically reduced release cycles for its microcontrollers, announcing 3 new models in the last 6 months. This without sacrificing innovation, coming to present the first microcontroller with support for 802.11ax (Wi-Fi 6), namely ESP32-C6.

Given the explosion of microcontrollers, I think I have do some tidying up with a comparison table, which can be found below and at the following link on Github. Unfortunately the table is not complete because the complete datasheets have not yet been released for the last 2 announced MCUs (ESP32-S3 and ESP32-C6). It will be updated as soon as all information is made available.

In the table I have reported all the models released by Espressif, namely ESP8266, ESP32, ESP32-S2, ESP32-C3, ESP32-S3, and the latest ESP32-C6. Obviously the comparison with the latest arrivals is merciless (actually 7 years have passed since its release), but it can be useful to understand in practice the improvements that have occurred between the various releases.

Anyway, you will notice that with the last 2 releases Espressif has finally divided its processors into 2 macro groups. The first group includes high-end microprocessors, for devices that don't have to tradeoff, while the second group includes cheaper ones, with fewer features but benefiting from Wi-Fi and Bluetooth connectivity like their full-grown couterparts.

Furthermore, Espressif has recently released ESP Product Selector, a service to compare all available models in all their variations and revisions. Unfortunately it is possible to compare only 3 models at a time, and some information that could be relevant, such as DMA and timer available, is not shown, so for a faster and more effective overview I recommend this table.

Tabella 1: Comparison of Espressif microcontroller families.
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 ULP-RISC-V ? X ?
Cryptographic Accelerator X 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 ?
UART 2 (one TX only) 3 2 ? 2 ?
SDIO Host 0 1 0 2 0 0
SDIO Slave 0 1 0 0 0 0
GPIO 17 34 43 44 22 22
LED PWM 5 16 8 ? 6 ?
MCPWM 0 6 0 2 0 0
Pulse counter 0 8 4 ? 0 X
GDMA* 0 0 0 ? 6 ?
USB X X USB OTG 1.1 ? Serial/JTAG ?
TWAI** 0 1 1 ? 1 ?
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 over DMA. With General DMA term, Espressif intends a specific DMA peripheral in full control of user. He will be responsible to manage such peripheral.

** In some old datasheet and documentation, it was referred as CAN bus.

*** A timer is dedicated to Wi-Fi, so you cannot freely use it.

The table will be updated as new information will be released. Contributions and suggestions are welcomed!

Bibliography and other documents

  1. The comparison of Espressif's boards
  2. ESP Product Selector
  3. Official announcement for ESP32-C6

Totale: 4ms

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