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ESP32-S31: Dual-Core RISC-V SoC with Wi-Fi 6, Bluetooth 5.4, and Advanced HMI
- ricardobeat 6mo agoI hope this one has multiple radios so you can actually use BT/Wifi/Thread simultaneously.
- bestouff 6mo agoIs there something that match those elsewhere ?
- hannesfur 6mo agoNot across all features, but certainly in specific ones. There are more advanced WiFi 6 chips, more advanced Bluetooth chips and faster MCUs. But they are all separate chips or companion ICs.
- moepstar 6mo agoI 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…
- 3form 6mo agoThis 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?
- jwr 6mo agoPoE 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.
- ldng 6mo agoAnd what would a better alternative look like ?
- timschmidt 6mo agoI 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.
- jwr 6mo agoThere is none, I never said PoE is "bad": it's a very good solution, it's just difficult to implement.
- Etheryte 6mo agoWhenever 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.
- solarkraft 6mo agoI’m sure the other commenters are right, but I’m guessing market segmentation may play a role here too.
- easygenes 6mo agoA 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/AG9705-2BR/21187225 https://www.digikey.com/en/products/detail/silvertel/AG9705-...
- throwup238 6mo agoEthernet is already one of the most expensive standards because you need magnetics for isolation. Adding power on top of that is genuinely expensive.
- Aurornis 6mo agoPoE power supplies need to be isolated (except in rare exceptions) and handle much higher voltages than common USB-C or wall wart power supplies. They have to use a transformer and a more complex control strategy, not a simple buck regulator with an inductor. PoE inputs need to tolerate voltages several times higher than the highest USB-C voltages, so more expensive parts are used everywhere.
- cruffle_duffle 6mo agoIt sounds like the PoE spec was designed before the arrival of “IoT” type things like the esp32, raspberry pi’s, etc. How much of the complexity is a “fundamental electrical engineering problem” and how much of it is just a spec written to solve a different set of problems?
- cpgxiii 6mo agoAlmost all of the complexity of PoE is fundamental. To get enough power over 100m of ethernet cable (10x longer than USB) you have to run at much higher voltages like 48V. The same has eventually come to USB: for USB-C Pd to reach 240W, it also has to use 48V. There have long been lower-voltage "passive PoE" systems which expect a lower always-on voltage on some of the ethernet pairs (usually 12V, 24V, or rarely 48V), which can be very easy to implement so long as your users can handle the setup and incompatibility with other ethernet devices (in the most extreme case of passive PoE on 100Mb/s ethernet, you simply connect the positive pair to the input of the device and the negative pair to the ground, no additional hardware needed).
- namibj 6mo agoAny Ethernet (well, any RJ45 you expect in a home/office) has to have at least 1500V isolation from the RJ45 wire to anything metal that can be touched or is a connector on the device. A PoE-only device with no electrical connectors besides the RJ45 can just use a very cheap RJ45 port with integrated magnetics and PoE allowance (tiny bit bigger wires and a center pin exposed, less than 50ct more than the cheapest RJ45 with integrated magnetics) and a cheap buck from 40~80V to e.g. 5V. Oh, and a cheap bridge rectifier and some signaling resistors to take care of input polarity and signal to the source that we in fact want the approximately 50V that could hurt a device not made for it.
- Geof25 6mo agoThe 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.
- elcritch 6mo agoNah, 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-kits-for-data-transmission/olimex/ https://www.tme.com/us/en-us/details/esp32-poe/development-k... - https://wesp32.com/ 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-lab-monitor-using-spe-2a38a6 https://www.hackster.io/rahulkhanna/sustainable-real-time-la...
- matt_trentini 6mo agoWaiting for my ManT1S: https://www.crowdsupply.com/silicognition/mant1s https://www.crowdsupply.com/silicognition/mant1s
- baby_souffle 6mo agoI really wish there was a camera option. You’d have made wired doorbell cameras possible without a retrofit. I’d buy in a heartbeat
- albuic 6mo agoSPE with multidrop and PoDL would be awesome ! They are working on that and it will be everywhere.
- cpgxiii 6mo agoMultidrop SPE isn't going to outperform newer CAN versions though. Somewhere in the sub-100Mb/s (e.g. 10-20Mb/s range) is the practical maximum speed of a multidrop bus at useful lengths, and that essentially applies equally to CAN or SPE. The only way to really get faster in a "multidrop-like" sense is with logically loop-like systems like ethercat and Fibre Channel where each network segment is point-to-point and the nodes are responsible for the routing.
- deleted 6mo ago[deleted]
- amelius 6mo ago> 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.
- albuic 6mo ago> 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
- amelius 6mo agoI mean, if I just look at my house. There is just one ethernet outlet, but many power sockets. If I want to connect devices all over my house, the best way is to use wifi and usb power adapters. Not ethernet. Both solutions require 1 cable per device, but the first solution would require only short and thin cables, and the second solution would require very long cables which I don't know even how to do properly without milling my walls.
- stinkbeetle 6mo agoYep. Mains electricity is ubiquitous, highly interoperable, very reliable, very high power available per drop, can be outdoor capable, common standards, understandable by users, requiring no active components, with many on-call experts available who can come to fix problems or extend/alter connectivity. Mains power wall plates with inbuilt USB power outlets are even available at quite small cost if the look of the bigger plug and wiring is not appealing. PoE is much fewer of those things. Difficult to recommend it these days with wifi being fast and reliable and so widely used. Certainly not for average residential user.
- ImPostingOnHN 6mo agoThat's half the equation. The other half is the reliability and security of wifi, which is less than that of ethernet for people without physical access to my wall innards
- exe34 6mo agoCan't you run a 5V supply from where your router is all the way to every god damn device in your house, and then pretend the wifi is also going through it? If you just want it to be inconvenient, there's no reason to let a lack of PoE stop you!
- anigbrowl 6mo agoM5stack has PoE offerings
- armx40 6mo agoNo. It’s there already. I used Ethernet on esp32-p4 and it nicely hovers around 90-100 mbps with lan8720 chip.
- logicallee 6mo agoRoughly how much do you think this costs?
- ricardobeat 6mo agoGiven their history, I would guess <$6 a piece for a dev board, <$2 for the chip at scale.
- Lwrless 6mo agoI'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-numbers-explained/ https://developer.espressif.com/blog/2025/03/espressif-part-...
- maartin0 6mo agoIt reminds me a bit of the new STM32s (STM32MP2) which are actually 64 bit, but they kept the name STM32 because everyone knows it
- beng-nl 6mo agoDidn’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.)
- p_l 6mo agoIt 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)
- madduci 6mo agoI stopped following the producer logic when Intel went from Pentium 4 to Pentium D
- wosined 6mo agoThe 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?
- cdcarter 6mo agoWhat do you mean by that? bad support for what?
- ricardobeat 6mo agoArduino 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.
- whynotmaybe 6mo ago> there is drama around platform-io What do you mean ?
- ricardobeat 6mo agoBoards like the ESP32-C6, almost 5 years old, are not supported in PlatformIO with Arduino libraries, because they refuse to update the Arduino core in some kind of stand-off with Espressif. This has been going on for years. There is a fork [1] that offers support but none of it makes back upstream. As a hobbyist I've given up on PIO and moved to a barebones arduino-cli setup instead. Much lighter and less painful. [1] https://github.com/pioarduino/platform-espressif32 https://github.com/pioarduino/platform-espressif32
- mianos 6mo agoThat 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.
- MallocVoidstar 6mo ago
- Rochus 6mo agoThey 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.
- volemo 6mo agoThat’s a shame, it’d be a cool and, afaik, unique feature for this niche.
- Rochus 6mo agoMaybe Espressif will notice that there are no RV32 chips with MMU so far (at least to my knowledge); we only have 32 bit MCUs or then only 64 bits for the CPUs. Something like Cortex-A7 is missing.
- GeorgeHahn 6mo agoThere’s one incoming, https://baochip.github.io/baochip-1x/ https://baochip.github.io/baochip-1x/ It would be great to see more.
- volemo 6mo agoBaochip looks very interesting, and I highly respect bunnie's work, but I can't realistically say Baochip is a viable option for me, an unprofessional tinkerer.
- bschwindHN 6mo agoThe upcoming Baochip is an RV32 chip with an MMU, I believe. https://www.bunniestudios.com/blog/2026/baochip-1x-a-mostly-open-22nm-soc-for-high-assurance-applications/ https://www.bunniestudios.com/blog/2026/baochip-1x-a-mostly-... Edit - Oops GeorgeHahn beat me to it
- IshKebab 6mo ago
- volemo 6mo agoHow do Espressif’s RISC-V cores compare to existing ARM or RISC-V options in terms of power efficiency (computational power / electrical power)?
- xondono 6mo agoDon’t know the specifics of the Espressif RISC-V cores, but in general they can’t really compete on those aspects with ARM. ARM is a much more mature platform, and the licensing scheme helps somewhat to keep really good physical implementations of the cores, since some advances get “distributed” through ARM itself. Compute capabilities and power efficiency are very tied to physical implementations, which for the best part is happening behind closed doors.
- 6SixTy 6mo agoWithout being hands on, it's difficult to make a direct comparison. There's 2 processors according to CNX [0], and the HP core's instruction set might roughly be comparable to M55. [0] https://www.cnx-software.com/2026/03/24/esp32-s31-dual-core-risc-v-mcu-offers-gigabit-ethernet-wifi-bluetooth-and-802-15-4-connectivity/ https://www.cnx-software.com/2026/03/24/esp32-s31-dual-core-...
- urba_ 6mo agoI 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
- cbdevidal 6mo agoCan also be ordered on JLCPCB in a custom PCB: https://www.lcsc.com/product-detail/C22387510.html?s_z=n_ESP32-P4 https://www.lcsc.com/product-detail/C22387510.html?s_z=n_ESP...
- MallocVoidstar 6mo agoI 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.
- armx40 6mo agoI guess it hit mass production and then suddenly recalled and is now in sample status again with “X” variant. I designed boards using esp32-p4 and deployed and then suddenly local supply of esp32-p4 went dry. Now waiting for the x variant to go mass production but you can by samples directly from espressif for 3.33$.
- peteforde 6mo agoI have great news for you: after several years of growing frustration with Espressif's inability to launch this chip properly in NA, I found a company called Wireless Tag that presumably felt the same way and just did it themselves: https://en.wireless-tag.com/product-item-56.html https://en.wireless-tag.com/product-item-56.html I've now used this module in several projects. I love it. And I love (x3) the P4. It is amazingly powerful. A lot of folks talk about the P4 not having radios as a problem; I personally think that it's an advantage. The assumption that every device is a wifi/BT device is baffling to me. You'd have a very hard time convincing me to use anything but the WT0132P4-A1 at this point. They are cheaper than ESP32-S3-MINI-1U, too.
- 6mo ago
- amelius 6mo agoDoes it run Linux?
- la_oveja 6mo agowhy would you do that? (unless for the fun of it)
- bavell 6mo agoNo, missing a MMU.
- mrighele 6mo agoThere is μClinux [1] although it is not clear to me how much alive is the project I wish I could run DiscoBSD/RetroBSD [2] on an ESP32, I like the idea of running on a MCU something that was originally meant for a PDP/11 (2.11 BSD) [1] https://en.wikipedia.org/wiki/%CE%9CClinux https://en.wikipedia.org/wiki/%CE%9CClinux [2] https://github.com/chettrick/discobsd https://github.com/chettrick/discobsd
- duskwuff 6mo ago> although it is not clear to me how much alive is the project It's essentially dead. There are very few practical applications for it - modern embedded RTOSes are better suited to low-memory MMU-less parts, and SoCs with a MMU and more memory that can run a "real" Linux aren't very expensive.
- 6mo ago
- MrBuddyCasino 6mo ago> 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.
- 1e1a 6mo agoFor reference, the 4-bit PSRAM interface on the ESP32-S3 normally runs at 80 MHz (maximum 120 MHz) and shares bandwidth with the external flash. I wonder if it will be possible to (ab)use the faster PSRAM interface on the ESP32-S31 as a general purpose 8-bit parallel interface, eg. for ADCs...
- anymouse123456 6mo agoSince 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?
- khalic 6mo agoIt’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?
- xondono 6mo agoWell, that depends on what you count as a backdoor, but Espressif has had some questionable flaws: - Early (ESP8622) MCUs had weak security, implementation flaws, and a host of issues that meant an attacker could hijack and maintain control of devices via OTA updates. - Their chosen way to implement these systems makes them more vulnerable. They explicitly reduce hardware footprint by moving functionality from hardware to software. - More recently there was some controversy about hidden commands in the BT chain, which were claimed to be debug functionality. Even if you take them at their word, that speaks volumes about their practices and procedures. That’s the main problem with these kinds of backdoors, you can never really prove they exist because there’s reasonable alternative explanations since bugs do happen. What I can tell you is that every single company I’ve worked which took security seriously (medical implants, critical safety industry) not only banned their use on our designs, they banned the presence of ESP32 based devices on our networks.
- khalic 6mo ago
- Mashimo 6mo agoOh 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?
- zrail 6mo agoYou already can with nRF52 boards. Presumably they'll add ESP32 support soon too. https://esphome.io/components/zigbee/ https://esphome.io/components/zigbee/
- cataphract 6mo agoThe C6 and the H2 already support ZigBee. Their SDK has a thin layer on top of zboss.
- kunver 6mo agoSoon espressif will add TPU to their chips.
- 0x457 6mo agoHopefully it will be just added to https://github.com/espressif/esp-nn https://github.com/espressif/esp-nn on software side.
- burnt-resistor 6mo agoInteresting. 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.
- ivanjermakov 6mo agoHN title entropy record?
- phendrenad2 6mo agoOnly a few characters away from my password!
- bdavbdav 6mo agoLove 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)
- nirav72 6mo agoArgh…Wifi 6 , but 2.4ghz.
- hajile 6mo agoAdding 2 frequency ranges is more expensive. If you're going to choose just one, you should choose the one with the greatest backward compatibility.
- 0x457 6mo agoRealistically 2.4Ghz is far from "greatest backward compatibility" since there is a real benefit of running 5Ghz and 6Ghz only networks. 2.4Ghz makes sense because this tiny device does not need high speeds Wi-Fi connection, and deployment scenarios benefit from 2.4 GHz penetration more.
- hannesfur 6mo agoThere is an ESP-C5 (https://www.espressif.com/en/products/socs/esp32-c5 https://www.espressif.com/en/products/socs/esp32-c5) that supports 2.4 and 5 GHz dual-band WiFi. And unlike the ESP32-S31 you can buy it today.
- vlan0 6mo agoI 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?
- joshryandavis 6mo ago> I understand there are use cases for low bandwidth, high range. Use cases like IoT? The very thing this is for?
- vlan0 6mo agoIs what you described a truth for all IoT devices? If I have los of my AP, why do I need 2.4Ghz? Even so, what SNR do you truly need for this low bandwidth application? Where is the engineering here? I have a unique position of having a data set over 8000 APs with 40k unique devices. If you design properly, there is no need for 2.4 ever. 2.4Ghz congestion (with nearly no actual 802.11 traffic) is very high. To the point where the IoT folks are struggling.
- Havoc 6mo agoMy 2.4ghz is basically all IOT these days. Things that matter are on 5 or 6 ghz. Busy moving the entire thing to be entirely firewalled off given how clean the separation is
- vlan0 6mo ago>My 2.4ghz is basically all IOT these days. Yup. And it's exactly why some of my IoT admins are struggling. There is only so much spectrum to go around.
- Havoc 6mo agoDon't think you're ever going to reclaim that spectrum successfully. There must be billions of devices on it. Pretty much any other ghz number is a better bet
- madushan1000 6mo agoInteresting 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.
- zwirbl 6mo agoIt supports LE Audio, might help getting that tech some traction
- peterus 6mo agoIt 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?
- Scene_Cast2 6mo agoI had the same theory, but IIRC the H2 isn't much better with radio on.
- jxm262 6mo agoPerfect timing. I just started planning to build a DIY smartwatch and was looking into the S3. Having native zigbee support could be nice.
- alhirzel 6mo agoThe S3 (and other Espressif chips) are pretty power-hungry. May want to keep looking for a smartwatch application.
- jxm262 6mo agoS3 was just for me to do an initial prototype. Longer term was going to try with the C3, though I'm open to suggestions :)
- alhirzel 6mo agoYou could consider similar devices and what they have used. Another angle is to look at ULPMark results: https://www.eembc.org/ulpmark/ https://www.eembc.org/ulpmark/
- sgraz 6mo agoPardon for off topic. The designer in me hates that they used AI for every single asset in this release post, looks so amateurish.
- elevation 6mo agoAre there any US vendors with wifi/BLE-integrated MCUs -- a single package that does it all?
- hannesfur 6mo agoIt has become limited. Some have WiFi, some have Bluetooth but rarely both. There is the SiWx917M (https://www.silabs.com/wireless/wi-fi/siwx917-wireless-socs https://www.silabs.com/wireless/wi-fi/siwx917-wireless-socs) by SiliconLabs though. If we include western companies you get the NXP RW612 (https://www.nxp.com/products/wireless-connectivity/wi-fi-plus-bluetooth-plus-802-15-4/wireless-mcu-with-integrated-tri-radio-1x1-wi-fi-6-plus-bluetooth-low-energy-5-4-802-15-4:RW612 https://www.nxp.com/products/wireless-connectivity/wi-fi-plu...) which is dutch.
- peteforde 6mo agoHonestly, 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 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.