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NodeMCU ESP32-C3 WiFi and BLE IoT boards show up for about $4

152 points by watchdogtimer 5y ago

deregulateMed 5y ago
I assumed with the shortages that these went up in price. Or more specifically the link I previously used to buy node d1 mini has gone from $3 to $8. Guess I should have looked harder. I might pull the trigger and buy 10 of these for all sorts of purposes. On a side note, these made a bad taste in my mouth for Arduino. It's making me think all Brand names should be a red flag.
- detaro 5y ago
  > On a side note, these made a bad taste in my mouth for Arduino. Why?
  - dvfjsdhgfv 5y ago
    Probably because the official version seems more overpriced than Apple memory upgrades.
    - bityard 5y ago
      When you buy a branded Arduino, you're supporting the people who develop the hardware, software, libraries, documentation and learning resources, community platforms, and educational outreach.
      - dvfjsdhgfv 5y ago
        I know, and yet the fact that I can buy a Chinese clone literally 10x cheaper makes it seem a bit off. I mean, I happily spend $35 on a Raspbery Pi and don't feel it's overpriced.
        parsecs 5y ago
        That's a good part thanks to the fact that nobody other than RPi Foundation can get those Broadcom microprocessors for cheap. This fact really sets apart the money making ability of those two companies.
        hytdstd 5y ago
        I'm not sure that RPi foundation's skill is just in shmoozing Broadcom-- they just released their $4 Pico board, which seems to be their own design.
        krastanov 5y ago
        The educational materials, documentation, and software support are the main reason for the markup. I really enjoy the Espressif boards, but I have faced many undocumented bugs or incomplete features on them and have had to frequently manually modify the IDE for them to work. No such problems with Arduino/Adafruit/Sparkfun, which also create high quality educational materials (and yes, cost 4x (not 10x) more).
      - II2II 5y ago
        It is important and people should be willing to pay for that if they desire it. It is also important to offer products that don't offer the same degree of support if they do not want it. Ten years ago, I happily paid for an Arduino. I was interested in microcontrollers for about a decade at that point. Even though microcontrollers were inexpensive, I didn't get into them previously since I needed that extra support. Yet the Arduino development board and IDE provided that support in a form I found palatable at a price I could bear. (There were certainly alternatives that provided something similar, but they were expensive. There were certainly alternatives that were inexpensive, but they lacked support.) Ten years later, the situation is different. More experience means that I don't need as much support. For the most part, I just want a development board that I can solder a header onto. It's something that I may be willing to pay $10 for, but it is much harder to justify at twice the price. It looks like this is something that the Raspberry Pi Foundation realized with the Pico. The development tools are better compared to those provided by a microcontroller vendor than with those provided by Arduino. The board's price is better compared to those of eastern companies than western ones. The reality is that we need both. The reality is that western boards will probably be more expensive than eastern ones, but the price differential need not be so large when similar products are offered. EDIT: clarification.
        jjeaff 5y ago
        If everyone goes with the cheap Chinese clone, you can't have either. Because those cheap clones are so cheap because there is little to no R&D required. No software stack to create, etc. Because all of that work is being done by the more expensive, original brands. Support is likely only a small part of the cost.
        II2II 5y ago
        I have to disagree with your blanket statement. In some cases what you say is true, the cheap clone is piggybacking on the R&D of someone else. Yet the situation is definitely not so clearcut in the case of many development boards. The heart of a development board is the MCU. Assuming a genuine component is being used, the software stack is typically provided by the vendor of the MCU. The supporting circuitry is either well known or provided in the vendor's datasheets. In the case of basic boards, there is not much R&D happening. It is also worth noting that the software stack for many boards is open source. Let's ignore the compilers. They're typically based upon GCC, thus open source, but they are typically supported by the MCU vendor which is supported by MCU sales. Consider something like Arduino and MicroPython. Some board vendors undoubtedly invest in them, but it is open source. Others can use the products of their labours. Equally important, others can contribute to them. The board vendors who invest in the software also benefit from contributions. On top of all of that, Chinese firms aren't the only ones making clones and Chinese firms do more than create clones. For example: I haven't heard anything about Espressif parts being clones of original brands.
  - blhack 5y ago
    These cheap board have turned me sour on some of the brand name stuff. First of all the cheap Chinese boards are far more innovative than what I see coming out of the US. If there is something you can imagine doing with an ESP32, there is a good chance somebody in China is making a pre fabbed dev board for you that has exactly the peripherals you already need on it And they’re selling it for $8. The US equivalents which seem to do way less, last cost $50-100. I get it, and I do try to support those US companies as much as I can, but when I’m putting together a workshop and need 10 boards, it goes from impossible to “I can give every student their own board and they can keep it at the end”. These things are educational tools for me. The cost matters a lot.
    - dtwest 5y ago
      Not trying to take away from your main point but isn't Arduino Italian?
      - parsecs 5y ago
        I think he's referring more to the Arduino/Genuino ecosystem rather than solely the Arduino company itself and its products.
    - spfzero 5y ago
      Cypress sells PSoC dev/proto boards for as little as 4.99 IIRC, for Cortex M0+ chips. Lots of periphs on-chip and I/Os but not a lot of hw adapters. I've used one of their $10 PSoC 5 boards before for test automation. They do sell more expensive boards but those generally have detachable programmers, capacitive touch and lots of extra hardware.
colemannugent 5y ago
I wonder if these would be a good fit for the DIY mechanical keyboard scene. With a board like this it looks like all you'd need electronics-wise is a battery and a charge controller. I wouldn't think it would be too difficult to get QMK running on these. It doesn't look like these are close to the Pro Micro pinout though, so perhaps a shim PCB to wire things up correctly?
- zachruss92 5y ago
  From a hardware perspective, likely. The regular esp8266/esp32 chips are arduino-compatible. If I remember correctly a common chip for DIY keyboards are the Arduino Micros.
- user-the-name 5y ago
  I would assume that for a keyboard you'd want something with much lower power consumption.
- stavros 5y ago
  Only one of the newer ESP32 variants has USB HID support, so none of them are compatible (except for Bluetooth, but battery life there won't be good). There was someone who was porting QMK (or maybe ZMK) to ESP32, so hopefully that'll happen.
- MivLives 5y ago
  There's 6 extra pins over the promicro which is a footprint a lot of boards target. https://beta.docs.qmk.fm/developing-qmk/c-development/compatible_microcontrollers https://beta.docs.qmk.fm/developing-qmk/c-development/compat... list of things QMK supports. There are a few bluetooth keyboard controllers that already fit the bluetooth controller niche and are pin compatible (nice!nano). This having a microusb port would make it less appealing as well. Personally I'm more interested in the RP2040 Pro Micro variant. It uses KMK, works with circuit python and can have its keymap changed by editing a file on it rather than reflashing or being limited by Via/Vial.
- andrewcchen 5y ago
  I'd say they are bad because they aren't very power efficient. There are boards with nrf52 chips that already have qmk support iirc.
azdle 5y ago
Huh, I wonder why these have the same old CHG USB-Serial chip on them. The C3 has a built-in serial (and JTAG) USB interface. Maybe the software support isn't there yet?
- pantalaimon 5y ago
  The USB-Serial chip still works when your software on the main CPU (that runs the USB stack) has crashed
  - mmoskal 5y ago
    To re-flash it you have to reset while holding the GPIO0 down - this starts the ROM bootloader with USB. At least this is how ESP32-S2 works.
  - azdle 5y ago
    Sure, but (not actually knowing how the integrated controller works) I don't see why the hardware one couldn't do that too, especially since it seems to only be build to support CDC (serial) and JTAG. Are you sure that the integrated one doesn't? It just seems like an odd thing to leave out.
    - pantalaimon 5y ago
      I'm not following, there is only one CPU: It has to run your application and 'operating system' (usb stack, Wifi if used). Usually those MCUs don't have much memory protection, so when your app crashes down goes the whole thing. Writing UART is usually just writing data to a single register, fire and forget. This will still work if everything else is burning. (unless you screwed with the clocks) Now USB on the other hand is a complex best, you have to keep state and do two way communication. If you corrupted your memory, you won't be able to get a debug message out over USB.
  - Sprite_tm 5y ago
    Espressif guy here: Actually, unless the crash is so bad that it triggers a RTC watchdog or manages to mess up with clocks somehow, the C3 USB thing will also stay active if your program crashes. Unlike the USB in e.g. the ESP32S2, this is a hardware implementation that is more like we took an external usb-to-serial implementation and integrated it into the ESP32C3 silicon.
NortySpock 5y ago
RISC-V for $4.30 USD? Sounds like they'd sell like hotcakes... NodeMCU ESP32-C3S_KIt Specifications: Wireless module – AI Thinker ESP32-C3S (footprint compatible with ESP32-S / ESP32-WROOM-32D) with ESP32-C3 RISC-V processor @ 160 MHz, 2.4 GHz WiFi, Bluetooth 5.0 LE, 4MB flash, on-board PCB antenna, and IPEX connector (which may be soldered or not). USB – Micro USB port for power and programming via CH340C USB to TTL chip Expansion – 2x 15-pin headers with GPIO, SPI, UART, ADC, I2S, 3.3V, GND Misc – RGB LED, Reset key, user-programmable key Dimensions – 49 x 26 mm
- tyingq 5y ago
  I'd add 400kb SRAM to the spec list. Full data sheet: https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/...
- conk 5y ago
  When did ESP 32 switch to RISC-V? Are there any comparisons on how the change impacts performance?
  - snuxoll 5y ago
    There’s no “switch” (yet), the C3 is their new MCU with a RISC-V core, but they will be continuing to manufacture their Xtensa-based designs for some time.
  - tzs 5y ago
    They didn't switch to RISC-V. The added RISC-V. Their recent releases have been a mix: September 2019: ESP32-S2. Single core Xtensa LX7. November 2020: ESP32-C3. Single core RISC-V. December 2020: ESP32-S3. Dual core Xtensa LX7. April 2021: ESP32-C6: Single core RISC-V.
    - MrBuddyCasino 5y ago
      Didn't know the differences between the original ESP32 and the ESP32-S3, so I looked it up. The ESP32-S3 is basically an updated version. Major differences: Xtensa® dual-core 32-bit LX6 vs LX7 (better FPU I think?) BR/EDR + Bluetooth LE v4.2 vs Bluetooth LE v5.0 SRAM 520 vs 512 ROM 448 vs 384 USB OTG none vs 1 Plus some minor differences in the peripherals.
jason0597 5y ago
My dad buys loads of this stuff from eBay and Aliexpress, we got a lot of plastic boxes just filled with modules like this. It's a shame I don't have any ideas on what to do with them though, they just sit there doing nothing.
- gigel82 5y ago
  Son !?
- paulkrush 5y ago
  Yah, I bet there are 50 other people reading this wondering when their son started posting on HN.
  - fnordfnordfnord 5y ago
    My sons aren't named Jason but I still feel called out a little bit.
- tlack 5y ago
  Here are some quick ideas: 1. Home automation 2. Garden management 3. Vehicle data logger incl OBD2 via CAN 4. Open wifi-based services like a bulletin board for a cafe 5. Mesh sensor network 6. Retro gaming 7. Autonomous vehicle experiments (ESP32 can run TensorFlowLite)
  - epx 5y ago
    Any idea if this board supports BLE Mesh? I've been waiting for an affordable platform to play with Mesh (tried ZigBee but didn't like).
- fullstop 5y ago
  Here's a few things that I made with the esp8266: * Connected an accelerometer and hall effect sensor, used to know when the washing machine is in use and the state of the lid. I taped a magnet to the lid so that it can be sensed with the hall sensor, so no wires are moving / need to be managed. Sends a message if we've left clothes in the wash. * Fish tank lights with WS2812B strips * Water softener brine level sensor using an IR transmitter / receiver in the lid of the brine tank, lets me know when to add salt. * Plant moisture sensor, lets me know when to water. * 1x4 WS2812B lights that we can all use to mark ourselves as on a call, either through a web page or Telegram, so that we know to be quiet because someone is on some sort of video call. If you're using esp32 or esp8266 take a look at esphome.io for ideas -- you can do a ton of stuff without writing much code at all. Most of my projects are done with the Nodemcu framework because I have a soft spot for Lua, but I do use esphome.io to interact with some Mijia BLE temperature and humidity sensors.
antattack 5y ago
More importantly, ESP32-C3-WROOM-02-H4 module is $2 at mouser.com
- fr0sty 5y ago
  That is the bare module only, no breakout board, and is out-of-stock for at least another two months.
  - BoorishBears 5y ago
    The bare module isn't too bad, there are some excellent breakouts that are only for bare modules. But I can't recommend 16MB WROVER based boards enough for people making one-off projects. https://www.digikey.com/en/products/detail/espressif-systems/ESP32-WROVER-IE-16MB/11613133 https://www.digikey.com/en/products/detail/espressif-systems... 16MB of flash lets you use sooo many "creature comforts", and as an added bonus, a lot of them tend to be a more breadboard friendly width since the module itself is thinner and longer than the WROOM. Like with 4MB of flash, even something as simple a <sstream> is off limits, because that pulls in locale data, and that in turn blows up your binary size budget unless you turn off OTA (If you're making an actual product, then yeah obviously trading some creature comforts for a simpler codebase and a cheaper product is on the table)
zxcvgm 5y ago
From the datasheet, it looks like the C3 doesn't have the Ultra Low Power (ULP) co-processor. This co-processor was there on previous ESP32s and allowed you to run code for sensor monitoring or other basic tasks while the main CPU was stopped, consuming ~150µA. It can then wake the main CPU if certain conditions were met. Wonder why it was removed, and if this would prevent the C3 from being used in these kinds of low-power applications. Datasheet: https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/...
- postpawl 5y ago
  That’s what allowed ESP.deepSleep(uS)?
  - zxcvgm 5y ago
    I believe that's a wakeup triggered using the RTC timer, which is still available in the C3.
- willemmerson 5y ago
  Actually it only consumes 150uA when it's active so if it's just doing one reading a minute then it'll be closer to the deep sleep current which is 5uA or so. There is an awesome library (https://github.com/boarchuz/HULP https://github.com/boarchuz/HULP) which makes using the ULP much easier so that things like software i2c and ADC multisampling are trivial.
doesnotexist 5y ago
So these are for sale on AliExpress which I've found to be higher friction than other open marketplaces (ebay/amazon/etc). The last time I tried to buy something there, my checkout was interrupted by a notification asking that I submit ID and other info for screening to proceed, which I found surprising since I was buyer not a seller and was purchasing some rather mundane item, cables or jumpers, I can't remember. In the end, the result was I didn't complete the order because it didn't seem worth the trouble. Additionally, I'm a little hesitant to buy some items on AliExpress because I worry they suffer from the same counterfeit issues as other open marketplaces due to poor oversight over sellers. Except for on AliExpress I have even less of a sense of how to distinguish between sellers with established reputations or otherwise. Does anyone have any tips for how to best use AliExpress?
- emteycz 5y ago
  Are you sure this information isn't required because of your government? That's the case at least in the EU, and the EU gets angry if they miss people. Aliexpress tries to do what the regulators want, sadly they don't have user experience in mind.
  - OJFord 5y ago
    I didn't deal with that from the UK (which was at the time of my AliExpress orders in the EU).
    - emteycz 5y ago
      That's a long time ago. Aliexpress started asking me for this stuff only few months ago, which I believe is when EU made getting the info mandatory - that was definitely post-brexit.
      - OJFord 5y ago
        Well.. I suppose that's a matter of perspective, but if that's such a recent change then fair enough! What's the purpose of it? Does it have to be recorded & kept (in case police want to ask 'who bought x' or 'what did y buy' or something?) or is it just to check that the purchaser matches the billing details (fraud prevention?)?
YetAnotherNick 5y ago
ESP32(having more ram, more cores, more pins, more frequency, better than this in all the respect?) is available for $2-3 if you look for it. Why is $4 the news?
PragmaticPulp 5y ago
I’ve been using a preproduction version of this (they were distributed widely on social media) with good results. It’s another iteration of the ESP32 products, but it’s not necessarily better than the previous boards for every application. All of the ESP parts have significant differences that can make them more or less appropriate for certain application needs, so read the specs carefully rather than skipping straight to picking the latest part. My biggest wishlist item for Espressif would be to make a solid WiFi/BT part with SDIO interface that can be used as a radio for a Linux host SoC. Espressif provides a hosted version of the firmware for previous ESP boards ( https://github.com/espressif/esp-hosted#12-supported-esp-boards https://github.com/espressif/esp-hosted#12-supported-esp-boa... ) but it doesn’t integrate as cleanly as standard SDIO WiFi parts and their latest boards don’t support SDIO. There are many cheap WiFi/BT SDIO modules on the market, but I’d like to have one go-to solution that is known to work well, readily available, and cheap like the ESP parts are as wireless micros.
- dheera 5y ago
  I wonder if they are capable of having the convenience features of CircuitPython boards of being able to appear as a USB storage device that you just drop firmware or code into. That would be killer. Even more killer would be if you could just drop an "a.out" and have it work. I hate installing microcontroller toolchains, especially STM32 and all that DFU crap.
  - mmoskal 5y ago
    It has an USB controller, so the chip should be capable of exposing an USB drive. Unfortunately, for whatever reason they are running it through an USB-to-serial chip instead of using native USB. The same is the case for many ESP32-S2 boards...
    - dheera 5y ago
      Hm, I suppose USB serial is fine too, but we should make it support something simple like "gcc --arch=esp32 somefoo.c; cat a.out > /dev/ttyUSB0". Would be awesome if gcc can auto-fetch the cross-compiler like Docker does if you tell it to docker run <something you don't already have>.
eurasiantiger 5y ago
Make no mistake about it: these have been assembled using slave labour. Check out the soldering job if in doubt.
- rurban 5y ago
  I don't think that they are assembled in US prisons. Looks more like a typical Chinese assembly, with fully automatic placement machines.
  - eurasiantiger 5y ago
    Nicely twisted, but the implication was not about the US prison system. This does not look at all like the work of pick-and-place machines. No solder paste was used, much less flow soldering. This is all done by hand, by incompetent workers. That implies Xinjiang.
    - rurban 5y ago
      Bad soldering has no connection to slave labor then. Just bad management, keeping costs low. BTW Look at the price of a good soldering paste: EUR100 and wait-time 2 months.
      - eurasiantiger 5y ago
        Again, nicely twisted, but nothing here checks out. It is extremely likely these boards have been soldered by Uighurs in Xinjiang camps. Would you rather sit in a factory soldering RISC-V boards without pay or wait for your turn in a concentration camp where you can get indiscriminately beaten, raped, tortured and killed?
quaintdev 5y ago
Awesome. I wonder if, in future, ESP8266 chips will be replaced with this one since former is WiFi only. There really needs to exist an alternative WiFi chip from another manufacturer. It would significantly drive the price down due to competition. Currently there's no competition to Espressif in this segment. Maybe Raspberry Pi should come up with RP2040 WiFi chip. That would be amazing. While we are on this topic I did a lockdown project based on ESP8266 thought I had share :p https://www.ankshilp.com/monitoring_solar_panel_output_over_wifi/ https://www.ankshilp.com/monitoring_solar_panel_output_over_...
- megous 5y ago
  There's bl602.
  - quaintdev 5y ago
    Not available at all in India. Also, other international vendors don't seem to have it too.
- antoniuschan99 5y ago
  Esp32-S2 are pretty much the 8266 replacement chips. ESP8266 don't have secure boot or flash encryption so it's not good for production. C3 doesn't have Risc-V ULP, whereas the S2 does, but the S2 doesn't have BLE! I'm waiting for a RISC-V ESP with ULP and an actual low power consumption BLE. Espressif also announced the ESP32-WROOM-DA which is has dual antenna configuration, can't wait to see how it handles! Very cool project, I want to play with Solar Panels as well it looks very fun :). Please check out my project too :P https://www.kokonaut.com https://www.kokonaut.com
  - quaintdev 5y ago
    Cost of ESP32-S2 is 5 times that of 8266 at least in India. From price perspective C3 looks like replacement for 8266. BTW cool project.
    - 5y ago
phkahler 5y ago
Do these things have PWM suitable for power electronics applications? Meaning driving complementary pairs with dead time, center aligned, synced ADC reading, period start ISR...
- sitkack 5y ago
  There is an internal scheduler using the same core to run the wifi stack, so if you need hard realtime for power electronics control, I'd personally still run that off a dedicated chip.
  - spfzero 5y ago
    Second this. Heard of a lot of blown H-Bridge Mosfets that used MCUs to gate them. With (deterministic) hardware, there is a data sheet and test circuits so you can be sure.
  - meatmanek 5y ago
    You'd probably offload PWM onto the in-chip PWM peripheral, rather than doing it in software. There isn't a lot of info about it in the datasheet[1], and based on my quick skim, the ESP-IDF docs[2] don't say anything about complementary pairs. 1. https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/... 2. https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/ledc.html?highlight=pwm https://docs.espressif.com/projects/esp-idf/en/latest/esp32/...
    - phkahler 5y ago
      >> You'd probably offload PWM onto the in-chip PWM peripheral, rather than doing it in software. Of course. In power we need specific features in the PWM peripheral. In particular complementary pairs with programmable dead tine. It is also customary to have an interrupt every cycle to do measurement and control. Control output is the new duty cycle for the next period - we typically compute a new duty cycle every period. Weather this chip can handle that type of thing is what I was after in my original question. It seems like the answer is no.
londons_explore 5y ago
The datasheet suggests these chips support 802.11n, HT40, MCS7, which maps to 150 Mbits of data throughput. But with these little embedded systems, I know the software stack typically heavily limits throughput. Can anyone comment on real world data rates this can achieve?
londons_explore 5y ago
The datasheet says "Out-of-band blocking performance" is just -5dBm in some frequency ranges... Surely that is nowhere near enough to meet the FCC requirements to still operate when faced with other unrelated radio transmissions?
Raed667 5y ago
I have been playing with a couple of NodeMCUs for a hobby project and I have to say the documentation and tooling are extremely poor (at least with a Mac). If you're used to the plug-and-play Arduino, be ready to spend quite a bit of time on setup before even connecting to a WIFI.

152 points by watchdogtimer 5y ago

I assumed with the shortages that these went up in price. Or more specifically the link I previously used to buy node d1 mini has gone from $3 to $8. Guess I should have looked harder. I might pull the trigger and buy 10 of these for all sorts of purposes. On a side note, these made a bad taste in my mouth for Arduino. It's making me think all Brand names should be a red flag.

detaro 5y ago
> On a side note, these made a bad taste in my mouth for Arduino. Why?
- dvfjsdhgfv 5y ago
  Probably because the official version seems more overpriced than Apple memory upgrades.
  - bityard 5y ago
    When you buy a branded Arduino, you're supporting the people who develop the hardware, software, libraries, documentation and learning resources, community platforms, and educational outreach.
    - dvfjsdhgfv 5y ago
      I know, and yet the fact that I can buy a Chinese clone literally 10x cheaper makes it seem a bit off. I mean, I happily spend $35 on a Raspbery Pi and don't feel it's overpriced.
      - parsecs 5y ago
        That's a good part thanks to the fact that nobody other than RPi Foundation can get those Broadcom microprocessors for cheap. This fact really sets apart the money making ability of those two companies.
        hytdstd 5y ago
        I'm not sure that RPi foundation's skill is just in shmoozing Broadcom-- they just released their $4 Pico board, which seems to be their own design.
      - krastanov 5y ago
        The educational materials, documentation, and software support are the main reason for the markup. I really enjoy the Espressif boards, but I have faced many undocumented bugs or incomplete features on them and have had to frequently manually modify the IDE for them to work. No such problems with Arduino/Adafruit/Sparkfun, which also create high quality educational materials (and yes, cost 4x (not 10x) more).
    - II2II 5y ago
      It is important and people should be willing to pay for that if they desire it. It is also important to offer products that don't offer the same degree of support if they do not want it. Ten years ago, I happily paid for an Arduino. I was interested in microcontrollers for about a decade at that point. Even though microcontrollers were inexpensive, I didn't get into them previously since I needed that extra support. Yet the Arduino development board and IDE provided that support in a form I found palatable at a price I could bear. (There were certainly alternatives that provided something similar, but they were expensive. There were certainly alternatives that were inexpensive, but they lacked support.) Ten years later, the situation is different. More experience means that I don't need as much support. For the most part, I just want a development board that I can solder a header onto. It's something that I may be willing to pay $10 for, but it is much harder to justify at twice the price. It looks like this is something that the Raspberry Pi Foundation realized with the Pico. The development tools are better compared to those provided by a microcontroller vendor than with those provided by Arduino. The board's price is better compared to those of eastern companies than western ones. The reality is that we need both. The reality is that western boards will probably be more expensive than eastern ones, but the price differential need not be so large when similar products are offered. EDIT: clarification.
      - jjeaff 5y ago
        If everyone goes with the cheap Chinese clone, you can't have either. Because those cheap clones are so cheap because there is little to no R&D required. No software stack to create, etc. Because all of that work is being done by the more expensive, original brands. Support is likely only a small part of the cost.
        II2II 5y ago
        I have to disagree with your blanket statement. In some cases what you say is true, the cheap clone is piggybacking on the R&D of someone else. Yet the situation is definitely not so clearcut in the case of many development boards. The heart of a development board is the MCU. Assuming a genuine component is being used, the software stack is typically provided by the vendor of the MCU. The supporting circuitry is either well known or provided in the vendor's datasheets. In the case of basic boards, there is not much R&D happening. It is also worth noting that the software stack for many boards is open source. Let's ignore the compilers. They're typically based upon GCC, thus open source, but they are typically supported by the MCU vendor which is supported by MCU sales. Consider something like Arduino and MicroPython. Some board vendors undoubtedly invest in them, but it is open source. Others can use the products of their labours. Equally important, others can contribute to them. The board vendors who invest in the software also benefit from contributions. On top of all of that, Chinese firms aren't the only ones making clones and Chinese firms do more than create clones. For example: I haven't heard anything about Espressif parts being clones of original brands.
- blhack 5y ago
  These cheap board have turned me sour on some of the brand name stuff. First of all the cheap Chinese boards are far more innovative than what I see coming out of the US. If there is something you can imagine doing with an ESP32, there is a good chance somebody in China is making a pre fabbed dev board for you that has exactly the peripherals you already need on it And they’re selling it for $8. The US equivalents which seem to do way less, last cost $50-100. I get it, and I do try to support those US companies as much as I can, but when I’m putting together a workshop and need 10 boards, it goes from impossible to “I can give every student their own board and they can keep it at the end”. These things are educational tools for me. The cost matters a lot.
  - dtwest 5y ago
    Not trying to take away from your main point but isn't Arduino Italian?
    - parsecs 5y ago
      I think he's referring more to the Arduino/Genuino ecosystem rather than solely the Arduino company itself and its products.
  - spfzero 5y ago
    Cypress sells PSoC dev/proto boards for as little as 4.99 IIRC, for Cortex M0+ chips. Lots of periphs on-chip and I/Os but not a lot of hw adapters. I've used one of their $10 PSoC 5 boards before for test automation. They do sell more expensive boards but those generally have detachable programmers, capacitive touch and lots of extra hardware.

colemannugent 5y ago

I wonder if these would be a good fit for the DIY mechanical keyboard scene. With a board like this it looks like all you'd need electronics-wise is a battery and a charge controller. I wouldn't think it would be too difficult to get QMK running on these. It doesn't look like these are close to the Pro Micro pinout though, so perhaps a shim PCB to wire things up correctly?

zachruss92 5y ago
From a hardware perspective, likely. The regular esp8266/esp32 chips are arduino-compatible. If I remember correctly a common chip for DIY keyboards are the Arduino Micros.
user-the-name 5y ago
I would assume that for a keyboard you'd want something with much lower power consumption.
stavros 5y ago
Only one of the newer ESP32 variants has USB HID support, so none of them are compatible (except for Bluetooth, but battery life there won't be good). There was someone who was porting QMK (or maybe ZMK) to ESP32, so hopefully that'll happen.
MivLives 5y ago
There's 6 extra pins over the promicro which is a footprint a lot of boards target. https://beta.docs.qmk.fm/developing-qmk/c-development/compatible_microcontrollers https://beta.docs.qmk.fm/developing-qmk/c-development/compat... list of things QMK supports. There are a few bluetooth keyboard controllers that already fit the bluetooth controller niche and are pin compatible (nice!nano). This having a microusb port would make it less appealing as well. Personally I'm more interested in the RP2040 Pro Micro variant. It uses KMK, works with circuit python and can have its keymap changed by editing a file on it rather than reflashing or being limited by Via/Vial.
andrewcchen 5y ago
I'd say they are bad because they aren't very power efficient. There are boards with nrf52 chips that already have qmk support iirc.

azdle 5y ago

Huh, I wonder why these have the same old CHG USB-Serial chip on them. The C3 has a built-in serial (and JTAG) USB interface. Maybe the software support isn't there yet?

pantalaimon 5y ago
The USB-Serial chip still works when your software on the main CPU (that runs the USB stack) has crashed
- mmoskal 5y ago
  To re-flash it you have to reset while holding the GPIO0 down - this starts the ROM bootloader with USB. At least this is how ESP32-S2 works.
- azdle 5y ago
  Sure, but (not actually knowing how the integrated controller works) I don't see why the hardware one couldn't do that too, especially since it seems to only be build to support CDC (serial) and JTAG. Are you sure that the integrated one doesn't? It just seems like an odd thing to leave out.
  - pantalaimon 5y ago
    I'm not following, there is only one CPU: It has to run your application and 'operating system' (usb stack, Wifi if used). Usually those MCUs don't have much memory protection, so when your app crashes down goes the whole thing. Writing UART is usually just writing data to a single register, fire and forget. This will still work if everything else is burning. (unless you screwed with the clocks) Now USB on the other hand is a complex best, you have to keep state and do two way communication. If you corrupted your memory, you won't be able to get a debug message out over USB.
- Sprite_tm 5y ago
  Espressif guy here: Actually, unless the crash is so bad that it triggers a RTC watchdog or manages to mess up with clocks somehow, the C3 USB thing will also stay active if your program crashes. Unlike the USB in e.g. the ESP32S2, this is a hardware implementation that is more like we took an external usb-to-serial implementation and integrated it into the ESP32C3 silicon.

NortySpock 5y ago

RISC-V for $4.30 USD? Sounds like they'd sell like hotcakes... NodeMCU ESP32-C3S_KIt Specifications: Wireless module – AI Thinker ESP32-C3S (footprint compatible with ESP32-S / ESP32-WROOM-32D) with ESP32-C3 RISC-V processor @ 160 MHz, 2.4 GHz WiFi, Bluetooth 5.0 LE, 4MB flash, on-board PCB antenna, and IPEX connector (which may be soldered or not). USB – Micro USB port for power and programming via CH340C USB to TTL chip Expansion – 2x 15-pin headers with GPIO, SPI, UART, ADC, I2S, 3.3V, GND Misc – RGB LED, Reset key, user-programmable key Dimensions – 49 x 26 mm

tyingq 5y ago
I'd add 400kb SRAM to the spec list. Full data sheet: https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/...
conk 5y ago
When did ESP 32 switch to RISC-V? Are there any comparisons on how the change impacts performance?
- snuxoll 5y ago
  There’s no “switch” (yet), the C3 is their new MCU with a RISC-V core, but they will be continuing to manufacture their Xtensa-based designs for some time.
- tzs 5y ago
  They didn't switch to RISC-V. The added RISC-V. Their recent releases have been a mix: September 2019: ESP32-S2. Single core Xtensa LX7. November 2020: ESP32-C3. Single core RISC-V. December 2020: ESP32-S3. Dual core Xtensa LX7. April 2021: ESP32-C6: Single core RISC-V.
  - MrBuddyCasino 5y ago
    Didn't know the differences between the original ESP32 and the ESP32-S3, so I looked it up. The ESP32-S3 is basically an updated version. Major differences: Xtensa® dual-core 32-bit LX6 vs LX7 (better FPU I think?) BR/EDR + Bluetooth LE v4.2 vs Bluetooth LE v5.0 SRAM 520 vs 512 ROM 448 vs 384 USB OTG none vs 1 Plus some minor differences in the peripherals.

jason0597 5y ago

My dad buys loads of this stuff from eBay and Aliexpress, we got a lot of plastic boxes just filled with modules like this. It's a shame I don't have any ideas on what to do with them though, they just sit there doing nothing.

gigel82 5y ago
Son !?
paulkrush 5y ago
Yah, I bet there are 50 other people reading this wondering when their son started posting on HN.
- fnordfnordfnord 5y ago
  My sons aren't named Jason but I still feel called out a little bit.
tlack 5y ago
Here are some quick ideas: 1. Home automation 2. Garden management 3. Vehicle data logger incl OBD2 via CAN 4. Open wifi-based services like a bulletin board for a cafe 5. Mesh sensor network 6. Retro gaming 7. Autonomous vehicle experiments (ESP32 can run TensorFlowLite)
- epx 5y ago
  Any idea if this board supports BLE Mesh? I've been waiting for an affordable platform to play with Mesh (tried ZigBee but didn't like).
fullstop 5y ago
Here's a few things that I made with the esp8266: * Connected an accelerometer and hall effect sensor, used to know when the washing machine is in use and the state of the lid. I taped a magnet to the lid so that it can be sensed with the hall sensor, so no wires are moving / need to be managed. Sends a message if we've left clothes in the wash. * Fish tank lights with WS2812B strips * Water softener brine level sensor using an IR transmitter / receiver in the lid of the brine tank, lets me know when to add salt. * Plant moisture sensor, lets me know when to water. * 1x4 WS2812B lights that we can all use to mark ourselves as on a call, either through a web page or Telegram, so that we know to be quiet because someone is on some sort of video call. If you're using esp32 or esp8266 take a look at esphome.io for ideas -- you can do a ton of stuff without writing much code at all. Most of my projects are done with the Nodemcu framework because I have a soft spot for Lua, but I do use esphome.io to interact with some Mijia BLE temperature and humidity sensors.

antattack 5y ago

More importantly, ESP32-C3-WROOM-02-H4 module is $2 at mouser.com

fr0sty 5y ago
That is the bare module only, no breakout board, and is out-of-stock for at least another two months.
- BoorishBears 5y ago
  The bare module isn't too bad, there are some excellent breakouts that are only for bare modules. But I can't recommend 16MB WROVER based boards enough for people making one-off projects. https://www.digikey.com/en/products/detail/espressif-systems/ESP32-WROVER-IE-16MB/11613133 https://www.digikey.com/en/products/detail/espressif-systems... 16MB of flash lets you use sooo many "creature comforts", and as an added bonus, a lot of them tend to be a more breadboard friendly width since the module itself is thinner and longer than the WROOM. Like with 4MB of flash, even something as simple a <sstream> is off limits, because that pulls in locale data, and that in turn blows up your binary size budget unless you turn off OTA (If you're making an actual product, then yeah obviously trading some creature comforts for a simpler codebase and a cheaper product is on the table)

zxcvgm 5y ago

From the datasheet, it looks like the C3 doesn't have the Ultra Low Power (ULP) co-processor. This co-processor was there on previous ESP32s and allowed you to run code for sensor monitoring or other basic tasks while the main CPU was stopped, consuming ~150µA. It can then wake the main CPU if certain conditions were met. Wonder why it was removed, and if this would prevent the C3 from being used in these kinds of low-power applications. Datasheet: https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/...

postpawl 5y ago
That’s what allowed ESP.deepSleep(uS)?
- zxcvgm 5y ago
  I believe that's a wakeup triggered using the RTC timer, which is still available in the C3.
willemmerson 5y ago
Actually it only consumes 150uA when it's active so if it's just doing one reading a minute then it'll be closer to the deep sleep current which is 5uA or so. There is an awesome library (https://github.com/boarchuz/HULP https://github.com/boarchuz/HULP) which makes using the ULP much easier so that things like software i2c and ADC multisampling are trivial.

doesnotexist 5y ago

So these are for sale on AliExpress which I've found to be higher friction than other open marketplaces (ebay/amazon/etc). The last time I tried to buy something there, my checkout was interrupted by a notification asking that I submit ID and other info for screening to proceed, which I found surprising since I was buyer not a seller and was purchasing some rather mundane item, cables or jumpers, I can't remember. In the end, the result was I didn't complete the order because it didn't seem worth the trouble. Additionally, I'm a little hesitant to buy some items on AliExpress because I worry they suffer from the same counterfeit issues as other open marketplaces due to poor oversight over sellers. Except for on AliExpress I have even less of a sense of how to distinguish between sellers with established reputations or otherwise. Does anyone have any tips for how to best use AliExpress?

emteycz 5y ago
Are you sure this information isn't required because of your government? That's the case at least in the EU, and the EU gets angry if they miss people. Aliexpress tries to do what the regulators want, sadly they don't have user experience in mind.
- OJFord 5y ago
  I didn't deal with that from the UK (which was at the time of my AliExpress orders in the EU).
  - emteycz 5y ago
    That's a long time ago. Aliexpress started asking me for this stuff only few months ago, which I believe is when EU made getting the info mandatory - that was definitely post-brexit.
    - OJFord 5y ago
      Well.. I suppose that's a matter of perspective, but if that's such a recent change then fair enough! What's the purpose of it? Does it have to be recorded & kept (in case police want to ask 'who bought x' or 'what did y buy' or something?) or is it just to check that the purchaser matches the billing details (fraud prevention?)?

YetAnotherNick 5y ago

ESP32(having more ram, more cores, more pins, more frequency, better than this in all the respect?) is available for $2-3 if you look for it. Why is $4 the news?

PragmaticPulp 5y ago

I’ve been using a preproduction version of this (they were distributed widely on social media) with good results. It’s another iteration of the ESP32 products, but it’s not necessarily better than the previous boards for every application. All of the ESP parts have significant differences that can make them more or less appropriate for certain application needs, so read the specs carefully rather than skipping straight to picking the latest part. My biggest wishlist item for Espressif would be to make a solid WiFi/BT part with SDIO interface that can be used as a radio for a Linux host SoC. Espressif provides a hosted version of the firmware for previous ESP boards ( https://github.com/espressif/esp-hosted#12-supported-esp-boards https://github.com/espressif/esp-hosted#12-supported-esp-boa... ) but it doesn’t integrate as cleanly as standard SDIO WiFi parts and their latest boards don’t support SDIO. There are many cheap WiFi/BT SDIO modules on the market, but I’d like to have one go-to solution that is known to work well, readily available, and cheap like the ESP parts are as wireless micros.

dheera 5y ago
I wonder if they are capable of having the convenience features of CircuitPython boards of being able to appear as a USB storage device that you just drop firmware or code into. That would be killer. Even more killer would be if you could just drop an "a.out" and have it work. I hate installing microcontroller toolchains, especially STM32 and all that DFU crap.
- mmoskal 5y ago
  It has an USB controller, so the chip should be capable of exposing an USB drive. Unfortunately, for whatever reason they are running it through an USB-to-serial chip instead of using native USB. The same is the case for many ESP32-S2 boards...
  - dheera 5y ago
    Hm, I suppose USB serial is fine too, but we should make it support something simple like "gcc --arch=esp32 somefoo.c; cat a.out > /dev/ttyUSB0". Would be awesome if gcc can auto-fetch the cross-compiler like Docker does if you tell it to docker run <something you don't already have>.

eurasiantiger 5y ago

Make no mistake about it: these have been assembled using slave labour. Check out the soldering job if in doubt.

rurban 5y ago
I don't think that they are assembled in US prisons. Looks more like a typical Chinese assembly, with fully automatic placement machines.
- eurasiantiger 5y ago
  Nicely twisted, but the implication was not about the US prison system. This does not look at all like the work of pick-and-place machines. No solder paste was used, much less flow soldering. This is all done by hand, by incompetent workers. That implies Xinjiang.
  - rurban 5y ago
    Bad soldering has no connection to slave labor then. Just bad management, keeping costs low. BTW Look at the price of a good soldering paste: EUR100 and wait-time 2 months.
    - eurasiantiger 5y ago
      Again, nicely twisted, but nothing here checks out. It is extremely likely these boards have been soldered by Uighurs in Xinjiang camps. Would you rather sit in a factory soldering RISC-V boards without pay or wait for your turn in a concentration camp where you can get indiscriminately beaten, raped, tortured and killed?

quaintdev 5y ago

Awesome. I wonder if, in future, ESP8266 chips will be replaced with this one since former is WiFi only. There really needs to exist an alternative WiFi chip from another manufacturer. It would significantly drive the price down due to competition. Currently there's no competition to Espressif in this segment. Maybe Raspberry Pi should come up with RP2040 WiFi chip. That would be amazing. While we are on this topic I did a lockdown project based on ESP8266 thought I had share :p https://www.ankshilp.com/monitoring_solar_panel_output_over_wifi/ https://www.ankshilp.com/monitoring_solar_panel_output_over_...

megous 5y ago
There's bl602.
- quaintdev 5y ago
  Not available at all in India. Also, other international vendors don't seem to have it too.
antoniuschan99 5y ago
Esp32-S2 are pretty much the 8266 replacement chips. ESP8266 don't have secure boot or flash encryption so it's not good for production. C3 doesn't have Risc-V ULP, whereas the S2 does, but the S2 doesn't have BLE! I'm waiting for a RISC-V ESP with ULP and an actual low power consumption BLE. Espressif also announced the ESP32-WROOM-DA which is has dual antenna configuration, can't wait to see how it handles! Very cool project, I want to play with Solar Panels as well it looks very fun :). Please check out my project too :P https://www.kokonaut.com https://www.kokonaut.com
- quaintdev 5y ago
  Cost of ESP32-S2 is 5 times that of 8266 at least in India. From price perspective C3 looks like replacement for 8266. BTW cool project.
  - 5y ago

phkahler 5y ago

Do these things have PWM suitable for power electronics applications? Meaning driving complementary pairs with dead time, center aligned, synced ADC reading, period start ISR...

sitkack 5y ago
There is an internal scheduler using the same core to run the wifi stack, so if you need hard realtime for power electronics control, I'd personally still run that off a dedicated chip.
- spfzero 5y ago
  Second this. Heard of a lot of blown H-Bridge Mosfets that used MCUs to gate them. With (deterministic) hardware, there is a data sheet and test circuits so you can be sure.
- meatmanek 5y ago
  You'd probably offload PWM onto the in-chip PWM peripheral, rather than doing it in software. There isn't a lot of info about it in the datasheet[1], and based on my quick skim, the ESP-IDF docs[2] don't say anything about complementary pairs. 1. https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf https://www.espressif.com/sites/default/files/documentation/... 2. https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/ledc.html?highlight=pwm https://docs.espressif.com/projects/esp-idf/en/latest/esp32/...
  - phkahler 5y ago
    >> You'd probably offload PWM onto the in-chip PWM peripheral, rather than doing it in software. Of course. In power we need specific features in the PWM peripheral. In particular complementary pairs with programmable dead tine. It is also customary to have an interrupt every cycle to do measurement and control. Control output is the new duty cycle for the next period - we typically compute a new duty cycle every period. Weather this chip can handle that type of thing is what I was after in my original question. It seems like the answer is no.

londons_explore 5y ago

The datasheet suggests these chips support 802.11n, HT40, MCS7, which maps to 150 Mbits of data throughput. But with these little embedded systems, I know the software stack typically heavily limits throughput. Can anyone comment on real world data rates this can achieve?

londons_explore 5y ago

The datasheet says "Out-of-band blocking performance" is just -5dBm in some frequency ranges... Surely that is nowhere near enough to meet the FCC requirements to still operate when faced with other unrelated radio transmissions?

Raed667 5y ago

I have been playing with a couple of NodeMCUs for a hobby project and I have to say the documentation and tooling are extremely poor (at least with a Mac). If you're used to the plug-and-play Arduino, be ready to spend quite a bit of time on setup before even connecting to a WIFI.