ESP32-S31

(espressif.com)

113 points | by volemo 2 hours ago ago

46 comments

  • randomint64 an hour ago

    Espressif is on fire! And the CPU even has SIMD instructions!

    RISC-V cores is a big deal for embedded systems because now compiling for SoCs is only a matter of `rustup target add riscv32imac-unknown-none-elf` instead of downloading half-broken proprietary toolchains and SDKs.

    Take a look at https://kerkour.com/introduction-to-embedded-development-wit... and https://kerkour.com/rust-esp32-pentest to get started with modern (Rust ;) embedded development.

    • phkahler an hour ago

      >> And the CPU even has SIMD instructions!

      Yes, but it looks like there is no hardware floating point. The description of the CORDIC module indicates fixed-point calculations, which is consistent with the lack of any reference to floating point.

      I am happy the have CAN-FD and Motor PWM module, but nowhere did I see conversion times listed for the ADC. For motor control I demand 1uS conversion time or less, and in the last year I've switched from fixed point to floating point after holding off on that switch for ~15 years.

      • polpo 28 minutes ago

        From the ESP32-S31 datasheet: "Single-precision floating-point unit (FPU) per core"

      • BenjiWiebe 7 minutes ago

        The datasheet apparently doesn't say, but judging by their other products' listed 12 bit SAR ADC sampling rates (and assuming this one is similar to what appears to be their standard ADC ) the conversion time will be on the order of 10uS.

      • NooneAtAll3 37 minutes ago

        where did you find cordic mention?

    • Havoc 28 minutes ago

      Nice. Been meaning to try rust on these sort of devices but the riscv I saw thus far seemed to be mixed arm and riscv which seemed weird

    • cassepipe an hour ago

      Curious: What does the "imac" stand for in the architecture target name ?

      • mentalpagefault 44 minutes ago

        IMAC are the RISC-V extensions supported:

        I = Base integer instruction set, 32-bit

        M = Standard extension for integer multiplication and division

        A = Standard extension for atomic instructions

        C = Standard extension for compressed instructions

        https://en.wikipedia.org/wiki/RISC-V#ISA_base_and_extensions

        • cassepipe 24 minutes ago

          Thanks.I can't believe they chose non-arcane, memory-friendly letters. Kind of rare in naming hardware I feel (unless it's not ?)

          • NekkoDroid 2 minutes ago

            I see you are unfamiliar with `rv64mafdcbvh_zicsr_zicntr_zihpm_ziccif_ziccrse_ziccrse_ziccamoa_zicclsm_za64rs_zihintpause_zic64b_zicbom_zicbop_zicboz_zfhmin_zkt_zihintntl_zicond_zimop_zcmop_zcb_zfa_zawrs_supm_svade_ssccptr_sstvecd_sstvala_sscounterenw_svpbmt_svinval_svnapot_sstc_sscofpmf_ssnpm_ssu64xl_sstateen_shcounterenw_shvstvala_shtvala_shvstvecd_shvsatpa_shgatpa` also known as `RVA23`

      • JdeBP an hour ago

        There are a few lettered extensions to the base RV32I instruction set. e.g.:

        * https://docs.riscv.org/reference/isa/unpriv/m-st-ext.html

      • NooneAtAll3 36 minutes ago

        where did you find it?

    • tosh an hour ago

      very interesting, do you have a pointer with more info on what kind of SIMD support it has?

      • bobmcnamara 25 minutes ago

        Hopefully comparable or better than ESP32S3.

        But with the weird alignment thing fixed

  • oritron 36 minutes ago

    The specs look great, will see how long it takes to get these as WROOM modules or on little dev boards; my two form factors of choice for Espressif devices. I'm also curious about the pricing, so far they've impressed me with how much more you get in successive generations at a similar price.

    If you're excited about the (relatively) speedy RISC-V cores and SIMD, look at the P4 which is available now. It has a slightly faster clock but no wireless: https://products.espressif.com/#/product-comparison?names=ES...

    There's some cool work out there using the dsp functionality and built in image handling to crunch a lot of pixel data, which should work similarly on the S31: https://www.reddit.com/r/WLED/comments/1ry2jd7/wledmmp4_with...

  • jml7c5 20 minutes ago

    Previous discussion from two months ago, when this was announced: https://news.ycombinator.com/item?id=47561678

  • frikk an hour ago

    I've been building hobby LED art projects with WLED (exclusively built on the ESP32 platform). It's been a blast. These little boards are so powerful and the open source community continues to amaze me.

    My preferred controller platform is of the QuinLED line - comes with power distribution, voltage regulators, fat copper lines, configurable data-line resistors, and smart auxiliary hardware support all for an affordable $30-$50 per controller. (quinled.info)

    <https://kno.wled.ge/> - WLED homepage and probably my favorite clever URL of all time.

  • Aurornis an hour ago

    Good to have WiFi and wired ethernet on the same part again.

    Although we lost the MIPI support that the P4 dual-core RISC-V line has.

    • tetris11 34 minutes ago

      How does wired internet technically work on these chips? Is it just 8 dedicated GPIO pins?

      • LeifCarrotson 17 minutes ago

        Not "just", it's (presumably) 8 dedicated pins that form an RMII interface. This is not the same 8 pins as you'll find in your 4-pair Ethernet cable, it's a separate protocol which can be connected to an Ethernet PHY transciever like a TI DP83867E [1], which is further connected to "magnetics" [2], a convenient package of 8 integrated transformers and chokes that provide the galvanic isolation feature of an Ethernet connection.

        A few SoCs provide integrated PHY transceivers, but usually it's an external chip.

        [1]: https://www.ti.com/lit/ds/symlink/dp83867e.pdf

        [2]: https://yageogroup.com/content/datasheet/asset/file/DATASHEE...

      • BenjiWiebe 16 minutes ago

        Looks like you need an external PHY. It can talk to the PHY with RGMII which uses 12 pins, which are muxed with GPIO8-19.

  • topspin 10 minutes ago

    I'm excited that this MCU and the P4 has RISC-V CLIC. That puts it at least on par with Cortex NVIC and enables bare metal frameworks like Rust RTIC to work really well.

  • mort96 24 minutes ago

    This looks like the long-awaited replacement for the original ESP32. The S and C series have been relatively low performance (the S better than the C but stuck on the outgoing Xtensa architecture), the P4 is powerful but lacks wireless. This is a relatively high performance, dual core MCU with wireless; a nice default option for low volume designs where being able to copy a previous implementation is more important than saving a few cents. Just like the ESP32. Nice.

    • swiftcoder 10 minutes ago

      Can it cope with TLS? The esp32 having a viable TLS stack has been a big win

  • zuzululu 21 minutes ago

    How do I order a few samples, seem like there is a MOQ ?

    Also I want to dive into hardware stuff but I'm always clueless as to what I do afterwards when this would arrive? Are you using a generic board or are you ordering and designing PCBs to hook this up to?

    What are you using it for ? How do I go from a prototype to mass production via kickstarter?

    • chrisco255 8 minutes ago

      Typically you look for a development board with the chip embedded on it. The dev board will have a usbc port and multiple pins that can be routed to LEDs, miniscreens, audio devices, etc. To program it you can usually use Lua (a very simple embedded language, almost JS-like) or you can use C/Rust/Zig as well. Arduino IDE works for it, too. You code from desktop and upload ROMs via USBC.

      You can plug the dev board into sandwich board for easier prototyping. To go to mass production, you'll need to hand off your prototype spec to a custom PCB maker that you can order from, prices vary a lot based on volume and some shops specialize in low volume for early products.

      Your end product should basically be a circuit board, case, battery, and any external components like LEDs or screens, then you assemble with plugs or wiring/soldering.

      It is sometimes possible to make a product from the dev boards, especially the small ones, but your product still has to get a custom FCC certification (not a deal breaker, just a hoop to jump through), whether using dev board or custom.

  • kjlldld 7 minutes ago

    Is anyone else worried that these chips are all made in China?

  • hart_russell 29 minutes ago

    Any reason why this device wouldn't have Z-Wave? Is the wireless protocol significantly different than Thread and Zigbee?

    • wiml 7 minutes ago

      As I understand it, Z-Wave is substantially more closed/proprietary. Both Thread and Zigbee are protocols that run on top of 802.15.4, which Espressif already has in other products.

    • mherkender 24 minutes ago

      I don't know for sure but Bluetooth, WiFi and Zigbee are on the same frequency band. Z-Wave is not.

      (at least in the US, not sure about other countries)

    • Aurornis 27 minutes ago

      This device only has a 2.4GHz radio. Z-Wave is sub-1GHz.

  • skybrian an hour ago

    I'm interested in audio out because I dabble in musical instruments.

    What's the state of Bluetooth audio out on microcontrollers? Is low latency and high quality output possible?

    • oritron 32 minutes ago

      Low latency in Bluetooth audio comes down to codecs and the best are proprietary.

      If you want to really cut down latency and need wireless with hardware like this, you could use a second ESP32 and send your own bitstream between them.

    • tliltocatl 32 minutes ago

      Is there any reason you want wireless? Bluetooth audio is a disaster, AFAIK. You don't want to use it for music. Just go wired, the ether is too cramped already.

      • skybrian 13 minutes ago

        There are alternatives, but being able to use an external amplified speaker and also move around easily would be nice. Maybe it's not feasible yet.

  • orphea 24 minutes ago

    It being RISC-V is awesome, but how does it make sense that it's S series when S series have been Xtensa cores? Why is it not C series?

  • nubinetwork 30 minutes ago

    This looks like a nucleo144, except its risc-v... but why would I use it over said nucleo144?

    • KZerda 19 minutes ago

      Better connectivity. The Nucleo 144 only has 100mbit ethernet, as far as I can tell, but the new ESP chip has gigabit, along with wireless.

    • bobmcnamara 25 minutes ago

      WiFi+BLE?

      • mort96 20 minutes ago

        And even if you don't need WiFi + BLE for a particular project, you may need it for other projects, and it might have value for you to standardise on one ecosystem.

  • jeremywho an hour ago

    When can we buy these?

    • Scene_Cast2 an hour ago

      The dev boards are already up for sale. I'm personally looking forward to the modules being stocked on LCSC, no idea when though.

      • topspin 36 minutes ago

        > The dev boards are already up for sale.

        I didn't expect to see that for a while yet. Not the usual Espressif announce and wait a year+ pattern.

  • rie_t an hour ago

    Love to see more RISC-V in the wild

  • Imustaskforhelp an hour ago

    The 1GB bandwidth is interesting. It also has Simd instructions too.

    Could this theoretically be used as a router or wireguard vpn instance?

    • KZerda 23 minutes ago

      Theoretically, yeah. Though at 320Mhz, with only 2.4ghz wireless, even with two cores, I doubt it's going to get anywhere near the throughput to fill the gigabit connection.