ESP32-S31: Dual-Core RISC-V SoC with Wi-Fi 6, Bluetooth 5.4, and Advanced HMI (espressif.com)

Is there something that match those elsewhere ?

I believe this is the first ESP to gain Ethernet capability?

I totally wish that a board would come with PoE…

Because as it is right now, powering a fleet of those with USB power supplies is annoying as fsck…

Roughly how much do you think this costs?

I'm puzzled by Espressif's naming here. We had the ESP32-S3, so "S31" sounds like "S3, variant 1," but this part doesn't really look like a simple S3 variant. And then there's an ESP32-E22, but no E21 or even a plain E2 anywhere.

Edit: found an article explaining some of their naming logic, and said that the SoC naming will get its follow-up article, but sadly it never happened. https://developer.espressif.com/blog/2025/03/espressif-part-...

The ESP32 boards I own have bad support and are a bit of a hit and miss. (arduino nano esp32) Did this get better? Or is the support still messy?

They claim that the chip has an "MMU". But unfortunately this doesn't seem to be a true RISC-V MMU (according to the Sv32 specification) integrated into the CPU core itself, but just a peripheral designed for memory mapped SPI flash and PSRAM. So as far as I understand there is no true process isolation with page faults and dynamic paging.

I hope this one has multiple radios so you can actually use BT/Wifi/Thread simultaneously.

How do Espressif’s RISC-V cores compare to existing ARM or RISC-V options in terms of power efficiency (computational power / electrical power)?

I don’t trust Espressif’s releases, I am still waiting for ESP32-P4 to hit distributors. It is now more than 2 years and 3rd chip revision

Does it run Linux?

> high-speed 250 MHz 8-bit DDR PSRAM with concurrent flash and PSRAM access

This is perhaps lost in the noise but IMO a large deal. PSRAM starting to get serious bandwidth.

Since the Snowden leaks in 2013, it just doesn't make sense that *any* foreign customers would put US technology inside their firewall. But they do.

It shocks me even more that any Western customer would do the same with network-connected Chinese chips. But we do.

The Espressif chips are truly incredible value, but what are we doing here?

Is there any doubt that these don't represent a major attack surface if a conflict were to heat up?

If you had network-connected chips of your own design inside every household of your adversary, what could you do with that?

Oh neat. Zigbee support.

I wonder if I at some point can create low power devices with EspHome for home assistant. I assume this should use less power than connecting to wifi?

Soon espressif will add TPU to their chips.

Interesting.

Although, I'd like to seem some non-paid blogger head-to-head reviews benchmarking instruction cycle efficiency per power of comparable Arm vs. ESP32 Xtensa LX6* and RISC-V parts.

* Metric crap tons of WROOM parts are still available and ancient ESP8266 probably too.

HN title entropy record?

Love ESP boards, and with Raspberry pi pricing though the roof, I’m hoping more will discover the love of getting the job done on a 10mm2 package.

I suspect a lot of the things people are using RPi for are better served by things like this (and virtualisation for the heavier end)

Argh…Wifi 6 , but 2.4ghz.

I don't understand what possesses these folks to continue making 2.4ghz devices. I understand there are use cases for low bandwidth, high range. But surely we've passed the point where that is more desirable to most than lower latency and high throughput, right?

Interesting that they made a new chip with BLE+BR/EDR again. all the chips after the original ESP32 were BLE only. Hope this chip has good low power options so we can use it in Bluetooth audio workloads.

It would be good if this chip had good idle current comparable to other MCUs. I have used the ESP32S3 and it's idle current with the radio enabled, but not transmitting, is quite terrible.

My application needed both can bus and Bluetooth (though no wifi) so the S3 was one of the only options available. I'm sure the high current draw is because the wifi and ble share the same radio?

Perfect timing. I just started planning to build a DIY smartwatch and was looking into the S3. Having native zigbee support could be nice.

Pardon for off topic. The designer in me hates that they used AI for every single asset in this release post, looks so amateurish.

Are there any US vendors with wifi/BLE-integrated MCUs -- a single package that does it all?

Honestly, I have very little interest in this module. I was a frequent S3 user who switched to the P4 last year when I realized that I could buy it in a WROOM-sized package:

https://en.wireless-tag.com/product-item-56.html

The P4 is an amazing part, and the WT0132P4-A1 is cheap, highly available and easy to use. It has so much horsepower, and it's not encumbered by the mandatory wifi/BT stacks. It also has a genuinely superior capacitive touch solution compared to the S3.

For those of you who need radios, the recommended solution is to add a C3 as a coprocessor. I think this makes way more sense than bundling them, because it means you are free to use newer radio chips as they come out; this also makes the P4 somehow cheaper than the S3-MINI modules.

As for the S31, I just hope that they finally fixed the issues with ADC2.