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.
It was because IA-64 was a completely different unrelated architecture that until AMD succeeded with K8 was "the plan" for both 64bit intel roadmap and the roadmap to kill off compatible vendors (AMD, VIA)
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.
Maybe Espressif will notice that there are no RV32 chips with MMU so far (at least to my knowledge); we only have 32 MCUs or then only 64 bits for the CPUs. Something like Cortex-A7 is missing.
Nah, ESP32's have had ethernet capability for a while and ESP-IDF supports it well. I've been using one I built for 5+ years now. Unfortunately RMII (ethernet phy) interface takes up a lot of the GPIO pins. This part looks like it'll remedy that issue.
There's two ESP32 boards that have been around for a while with PoE:
> You don't need long cables, just a local power source
Which means batteries that have to be replaced and maintained or cables... So ethernet with PoE or even better SPE (single pair Ethernet) with PoDL (power over data lines which is PoE for SPE) is the best from my point of view
On that note, why does the PoE capability often add such a big proportion of the price of various items? Is the technology really costly for some reason, or is it just more there's fairly low demand and people are still willing to pay?
PoE is not obvious to implement (take it from someone who has done it with a fair share of mistakes), uses more expensive components that normal ethernet, takes up more space on the board, makes passing emissions certification more complex, and is more prone to mistakes that ruin boards in the future, causing support/warranty issues. In other words, a bag of worms: not impossible to handle, but something you would rather avoid if possible.
I wouldn't call it "better", but the least-effort path among hobbyists and low end gear is often 12v or 24v sent over a pair with Gnd and a forgiving voltage regulator on the other end.
A full-module add-on in this power class is about $7 at 1,000 unit scale [0]. It would be around $3 with your own custom PCB design in terms of BoM addon at scale. That’s power only. Add another dollar or two for 10/100 PHY.
The trick is as others have said in what adding it to your design does in terms of complicating compliance design.
Whenever you combine two things into one, the complexity and cost go up considerably. A regular coffee machine is pretty cheap. Add high pressure so it can make espresso and it gets considerably more expensive. Add milk so it can make cappuccino, again more complex and expensive. The same holds for electronics. Isolating power when it's alone is fairly straightforward. It gets considerably more tricky and hence more expensive the moment you want to place any kind of a meaningful data signal in its vicinity.
I assume their chips don't really exist until they're actually supported by ESP-IDF. The ESP32-C5 was announced in June 2022, received initial support in -IDF in August 2025, and more complete support in December. It seems to have only recently started getting third party dev boards.
It’s not like creating a chip gives you unfettered access to it. You _can_ add 0-day flaws and backdoors, but these can be discovered, leaked, etc. Has there been any case of such a backdoor built in consumer chips like theses? I’m not talking about CIA ops like snowden described, that’s supply chain interception. I mean, has anybody ever found such a backdoor?
That native sdk and the vscode plugin are very professional. There is a bit of a learning curve to get into it, but once you do, it's very functional and the developers are super supportive. They have fixed bugs for me in days.
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-...
It reminds me a bit of the new STM32s (STM32MP2) which are actually 64 bit, but they kept the name STM32 because everyone knows it
Didn’t Intel also try to brand the 64bit x86 extensions as ia-32e initially? Seemed like wasting an opportunity to me.
(Disclaimer: I work at Intel but this was way before my tenure.)
It was because IA-64 was a completely different unrelated architecture that until AMD succeeded with K8 was "the plan" for both 64bit intel roadmap and the roadmap to kill off compatible vendors (AMD, VIA)
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.
That’s a shame, it’d be a cool and, afaik, unique feature for this niche.
Maybe Espressif will notice that there are no RV32 chips with MMU so far (at least to my knowledge); we only have 32 MCUs or then only 64 bits for the CPUs. Something like Cortex-A7 is missing.
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?
You already can with nRF52 boards. Presumably they'll add ESP32 support soon too.
https://esphome.io/components/zigbee/
The C6 and the H2 already support ZigBee. Their SDK has a thin layer on top of zboss.
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…
Nah, ESP32's have had ethernet capability for a while and ESP-IDF supports it well. I've been using one I built for 5+ years now. Unfortunately RMII (ethernet phy) interface takes up a lot of the GPIO pins. This part looks like it'll remedy that issue.
There's two ESP32 boards that have been around for a while with PoE:
- https://www.tme.com/us/en-us/details/esp32-poe/development-k... - https://wesp32.com/
I'm more hopeful for single-pair ethernet to gain momentum though! Deterministic, faster than CANBUS, single pair, with power delivery:
https://www.hackster.io/rahulkhanna/sustainable-real-time-la...
SPE with multidrop and PoDL would be awesome ! They are working on that and it will be everywhere.
Waiting for my ManT1S:
https://www.crowdsupply.com/silicognition/mant1s
> Because as it is right now, powering a fleet of those with USB power supplies is annoying as fsck…
Therefore, wifi is more convenient than ethernet.
You don't need long cables, just a local power source.
> You don't need long cables, just a local power source
Which means batteries that have to be replaced and maintained or cables... So ethernet with PoE or even better SPE (single pair Ethernet) with PoDL (power over data lines which is PoE for SPE) is the best from my point of view
The original ESP32 has Ethernet as well, I believe in the form of RMII. Then it has been removed from the chip, never specified the reason.
This would be great indeed.
On that note, why does the PoE capability often add such a big proportion of the price of various items? Is the technology really costly for some reason, or is it just more there's fairly low demand and people are still willing to pay?
PoE is not obvious to implement (take it from someone who has done it with a fair share of mistakes), uses more expensive components that normal ethernet, takes up more space on the board, makes passing emissions certification more complex, and is more prone to mistakes that ruin boards in the future, causing support/warranty issues. In other words, a bag of worms: not impossible to handle, but something you would rather avoid if possible.
And what would a better alternative look like ?
I wouldn't call it "better", but the least-effort path among hobbyists and low end gear is often 12v or 24v sent over a pair with Gnd and a forgiving voltage regulator on the other end.
A full-module add-on in this power class is about $7 at 1,000 unit scale [0]. It would be around $3 with your own custom PCB design in terms of BoM addon at scale. That’s power only. Add another dollar or two for 10/100 PHY.
The trick is as others have said in what adding it to your design does in terms of complicating compliance design.
[0] https://www.digikey.com/en/products/detail/silvertel/AG9705-...
Ethernet is already one of the most expensive standards because you need magnetics for isolation. Adding power on top of that is genuinely expensive.
Whenever you combine two things into one, the complexity and cost go up considerably. A regular coffee machine is pretty cheap. Add high pressure so it can make espresso and it gets considerably more expensive. Add milk so it can make cappuccino, again more complex and expensive. The same holds for electronics. Isolating power when it's alone is fairly straightforward. It gets considerably more tricky and hence more expensive the moment you want to place any kind of a meaningful data signal in its vicinity.
I’m sure the other commenters are right, but I’m guessing market segmentation may play a role here too.
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
Can also be ordered on JLCPCB in a custom PCB: https://www.lcsc.com/product-detail/C22387510.html?s_z=n_ESP...
I assume their chips don't really exist until they're actually supported by ESP-IDF. The ESP32-C5 was announced in June 2022, received initial support in -IDF in August 2025, and more complete support in December. It seems to have only recently started getting third party dev boards.
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?
It’s not like creating a chip gives you unfettered access to it. You _can_ add 0-day flaws and backdoors, but these can be discovered, leaked, etc. Has there been any case of such a backdoor built in consumer chips like theses? I’m not talking about CIA ops like snowden described, that’s supply chain interception. I mean, has anybody ever found such a backdoor?
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 hope this one has multiple radios so you can actually use BT/Wifi/Thread simultaneously.
Does it run Linux?
why would you do that? (unless for the fun of it)
> 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.
Is there something that match those elsewhere ?
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?
That native sdk and the vscode plugin are very professional. There is a bit of a learning curve to get into it, but once you do, it's very functional and the developers are super supportive. They have fixed bugs for me in days.
Arduino nano are made by arduino using Espressif chips, and Arduino IDE support is indeed hit and miss.
ESP-IDF, the official C SDK, is a bit more work, and there is drama around platform-io, but it’s significantly more stable.
Don't use the Arduino framework, use ESP-IDF or Rust.
Roughly how much do you think this costs?
Given their history, I would guess <$6 a piece for a dev board, <$2 for the chip at scale.