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

https://www.cnx-software.com/2021/07/12/nodemcu-esp32-c3-wifi-ble-iot-boards/

by watchdogtimer • 5 years ago

152 116 5 years 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• 5 years ago

On a side note, these made a bad taste in my mouth for Arduino.

Why?

dvfjsdhgfv3• 5 years ago

Probably because the official version seems more overpriced than Apple memory upgrades.

blhack• 5 years 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.

colemannugent• 5 years 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• 5 years 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• 5 years ago

I would assume that for a keyboard you'd want something with much lower power consumption.

stavros• 5 years 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• 5 years 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/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• 5 years 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.

azdle2• 5 years 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?

pantalaimon2• 5 years ago

The USB-Serial chip still works when your software on the main CPU (that runs the USB stack) has crashed

mmoskal3• 5 years 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.

azdle2• 5 years 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.

Sprite_tm• 5 years 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• 5 years 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• 5 years ago

I'd add 400kb SRAM to the spec list.

Full data sheet: https://www.espressif.com/sites/default/files/documentation/...

conk• 5 years ago

When did ESP 32 switch to RISC-V? Are there any comparisons on how the change impacts performance?

snuxoll• 5 years 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• 5 years 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.

eurasiantiger6• 5 years ago

Look at the solder joints. How can they mass produce hand-soldered PCBs at that price?

X marks the spot.

IfOnlyYouKnew• 5 years ago

Slave labor.

qbasic_forever2• 5 years ago

Through-hole components like headers can be soldered by selective solder machines, for example: https://www.youtube.com/watch?v=2sm_qdeconI or https://www.youtube.com/watch?v=oaJ67KUOHiYhttps://www.youtu... They use a little 'fountain' of molten solder that's controlled by cnc to touch each component and solder it in place.

baybal2• 5 years ago

Easily, at 10 seconds per board, you get ~350 boards per hour at around ~$15 per hour.

jason05972• 5 years 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• 5 years ago

Son !?

paulkrush• 5 years ago

Yah, I bet there are 50 other people reading this wondering when their son started posting on HN.

fnordfnordfnord• 5 years ago

My sons aren't named Jason but I still feel called out a little bit.

tlack• 5 years 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• 5 years 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).

fullstop5• 5 years 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.

barbazoo• 5 years ago

I'm for sure going to copy your first one, thanks for sharing.

blackfawn• 5 years ago

Care to elaborate more on the IR sensor for a water softener? I had thought of doing something similar but with ultrasonic for level. I'm curious what you are doing with IR. I suppose resistance could be used based on dissolved salt but I like the non-contact options, when possible.

Abundnce10• 5 years ago

I love these ideas! I've always wanted to do home automation stuff but I worry about sending data to outside parties. Do you happen to know if Home Assistant monitors the things you have installed and/or keep track of the data your devices pass to each other?

otter-in-a-suit• 5 years ago

Forgive me if it's an ignorant question, but what's the benefit of an ESP32/ESP8266 over a Pi Zero (W), apart from saving ~$5, assuming all your applications are indoors and don't need to run on battery?

I've only recently gotten into the whole topic, and have yet to see the benefit of dealing with micro-controller toolchains, MicroPython etc. if power consumption is not a big factor. Seems like a full Raspbian offers a lot more flexibility.

I've used a Pi Zero W that runs regular Python and sends messages to a REST API on my home server (little go thing) + MariaDB + Grafana, for similar use case (although I will now need to build the washer/dryer idea :)).

triangleman• 5 years ago

The question is, if you did grab a box and tried to do something with it, how would your dad react?

zoomablemind2• 5 years ago

... It's a shame I don't have any ideas on what to do with them though, they just sit there doing nothing.

You've got the supply, that's good!

Now, if you have the interest, then asking your dad to show how these components could be practically used for something interesting could as well be a beginning of a wonderful journey.

Perhaps, your dad just needs such a signal from you. In my own experience, Snap Circuits set is currently providing this journey.

jason05972• 5 years ago

Oh I have interest in this stuff, it's just that it's pretty much useless for an engineering career. Plus, you can't really make any profit because a Chinese inventor will just copy your idea and scale it up and drive you out of whatever market you make.

To be honest I understand more on how these components work than my dad does, he usually just clicks on the first results on Google and glues together Arduino/Hackaday projects. Whenever I talk to him about doing real low level stuff and writing actual drivers, it always goes over his head.

zoomablemind2• 5 years ago

One of many resources about ESP32 and a quite informative overview of ESP32 realm is https://randomnerdtutorials.com/projects-esp32/

It also shows examples of projects to learn the use of the board.

toast02• 5 years ago

I've got 5 esp8266 based temperature/humidity probes hanging out around the house and collecting data once a minute. At some point, I'm going to use that to better control my central HVAC systems (mostly I want to run the fan more strategically), and alert on bad conditions.

Also, another two to use as an alternative controller (with opensource firmware) on a video conversion board; but I only installed one, because it didn't satisfy my hopes.

antattack• 5 years ago

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

fr0sty• 5 years ago

That is the bare module only, no breakout board, and is out-of-stock for at least another two months.

BoorishBears• 5 years 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...

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)

zxcvgm2• 5 years 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/...

postpawl• 5 years ago

That’s what allowed ESP.deepSleep(uS)?

zxcvgm2• 5 years ago

I believe that's a wakeup triggered using the RTC timer, which is still available in the C3.

willemmerson• 5 years 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) which makes using the ULP much easier so that things like software i2c and ADC multisampling are trivial.

doesnotexist• 5 years 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?

emteycz3• 5 years 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.

OJFord3• 5 years ago

I didn't deal with that from the UK (which was at the time of my AliExpress orders in the EU).

mnadkvlb• 5 years ago

Your mileage may vary. My experience so far has been mostly low quality stuff from aliexpress with very long shipping periods.

I found the ratings on aliexpress to be completely useless. as compared to aliexpress, even amazon ratings feel legit (which has probably the lowest reputation from my experience).

I had way better experience with local vendors here in Switzerland or even shipped from Germany for all kinds of qualities.

The local vendors here also have way better support and very quick shipping times.

toast02• 5 years ago

I've bought a couple items on AliExpress. For me, I had to call my card issuer and have them pause the anti-fraud systems for my card, so they would allow the charges; and then when I bought some more stuff a couple weeks later, I had to do it again. Some people on reddit report success or failure with different card issuers.

I would only use AliExpress to buy things you can't find anywhere else, which should help with counterfeit issues, AliExpress has seller ratings and what not, too. I've had some luck with BangGood.com for randomly produced NodeMCU style boards, and they have a US warehouse which helps with shipping speed (at additional cost).

OJFord3• 5 years ago

I don't really have any tips, it is more painful/friction-full than Amazon (which is in other ways deteriorating into it!) I agree. I've only used for things where I've suspected they're commodity dozen-'brand' 'drop shipped' items, and the AliExpress price has been enough cheaper for me to bother with it, and risk worse/non-existent return/refund experience (worst case could always charge back I suppose if bothered enough).

A lot of the time though, Amazon is O(tens of pence) more expensive, and I just view it as a cheap insurance. (Amazon's returns/replacements is great IME; AliExpress's is unknown to me and frankly I assume it's bad, and for the sake of tens of pence don't want to find out.)

megous2• 5 years ago

It's on par with local options when it comes to ease of use.

As for the sellers, I either know them due to their other online presence, or I select them based on how good the descriptions are on the items they sell from a technical perspective. Reviews are also useful, especially those with more text, photos, and some technical comments.

YetAnotherNick• 5 years 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• 5 years 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-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.

dheera6• 5 years 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.

mmoskal3• 5 years 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...

eurasiantiger6• 5 years ago

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

rurban2• 5 years ago

I don't think that they are assembled in US prisons. Looks more like a typical Chinese assembly, with fully automatic placement machines.

eurasiantiger6• 5 years 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.

quaintdev4• 5 years 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_...

megous2• 5 years ago

There's bl602.

quaintdev4• 5 years ago

Not available at all in India. Also, other international vendors don't seem to have it too.

antoniuschan992• 5 years 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

quaintdev4• 5 years 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.

phkahler2• 5 years 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• 5 years 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.

spfzero2• 5 years 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• 5 years 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/... 2. https://docs.espressif.com/projects/esp-idf/en/latest/esp32/...

londons_explore2• 5 years 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_explore2• 5 years 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• 5 years 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.

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

Related Stories