[HARDWARE REQUEST] Suggest that Espressif make ESP32-H2 or ESP32-C6 based USB dongle

[Hedda]

@lhespress related to this project, is there any chance you and your colleges working on the Zigbee and Thread protocols for ESP32 can convince management or product developers at Espressif to manufacture an ESP32-C6 or ESP32-H2 based USB dongle that tries to specifically target both developers and testers of Zigbee Coordinator USB radio dongles (and Thread Border Router USB radio adapters) with a USB-A or USB-C male plug?

That is, it would be very nice to have a PCB development board in USB-stick form factor with USB-A or USB-C male plug similar in design to the popular "nRF52840 Dongle" (from Nordic Semiconductor) for both makers and related to this the use case of easy desktop development and testing of Zigbee Coordinator USB dongles / Thread Border Router USB adapters. Do you have contacts with those that design reference development boards?

• https://www.nordicsemi.com/Products/Development-hardware/nrf52840-dongle

  • https://www.nordicsemi.com/Products/Development-hardware/nrf52840-dongle?lang=zh-CN

You can also find more information on the Zephyr project:

• https://docs.zephyrproject.org/latest/boards/nordic/nrf52840dongle/doc/index.html

Preferably with the PCB as open-source so that other third-party PCB manufacturers can modify and release their own variants with similar designs(?).

• Download nRF52840 Dongle product brief [PDF]

  • Download nRF52840 Dongle product brief Simplified Chinese [PDF]

"The nRF52840 Dongle is a small, low-cost USB dongle that supports Bluetooth 5.4, Bluetooth mesh, Thread, Zigbee, 802.15.4, ANT and 2.4 GHz proprietary protocols. The Dongle is the perfect target hardware for use with nRF Connect for Desktop as it is low-cost but still support all the short range wireless standards used with Nordic devices. The dongle has been designed to be used as a wireless HW device together with nRF Connect for Desktop. For other use cases please do note that there is no debug support on the Dongle, only support for programming the device and communicating through USB. It is supported by most of the nRF Connect for Desktop apps and will automatically be programmed if needed. In addition custom applications can be compiled and downloaded to the Dongle. It has a user programmable RGB LED, a green LED, a user programmable button as well as 15 GPIO accessible from castellated solder points along the edge. Example applications are available in the nRF5 SDK under the board name PCA10059."

PS: For reference, because Espressif now owns M5Stack an alternative option could be for them to make a AtomS3U ESP32C6 Development Kit with USB-A to match their existing AtomS3U ESP32S3 Development Kit with USB-A (SKU: K125), though their design has a Grove port instead of GPIO pins which perhaps does not meet the requirements of all developers(?):

• https://shop.m5stack.com/products/atoms3u?variant=43911717945601

PPS: Also check out these third-party designs of "nRF52840 Dongles" which for example uses other antenna designs:

• https://wiki.makerdiary.com/nrf52840-mdk-usb-dongle/

• https://tr.rfstariot.com/rf-dg-40a-nrf52840-usb-dongle_p86.html

• https://www.i-syst.com/article/usb-dongle-nordic-nrf-connect-desktop

[semaf]

Hehe.. the C6 and H2 is on our development plan :) Would be happy to share with you guys. We planned to have a regular USB connector but the way of Nordic looks better.

[Hedda]

Hehe.. the C6 and H2 is on our development plan :) Would be happy to share with you guys. We planned to have a regular USB connector but the way of Nordic looks better.

I believe that the idea with the Nordic Semi nRF52840 Dongle is two-fold; first to keep cost down so can sell them cheaper, and secondly to make it so that a user can technically break off the USB-plug part and re-use it as a just a radio module.

Home Assistant’s Connect ZBT-1 USB stick (previously sold as the Home Assistant SkyConnect) actually uses a somewhat similar PCB design, at least for the USB plug part, though they also added a nice plastic enclosure that makes it look nice for end users as well. So if you olan to make one then do check out its desiged here too:

• https://www.home-assistant.io/connectzbt1/

https://community.home-assistant.io/t/home-assistant-skyconnect-home-assistant-connect-zbt-1-the-official-zigbee-coordinator-or-thread-border-router-usb-radio-dongle-from-nabu-casa/433594?page=8

[Hedda]

Oh, but if you want to keep the PCB small then you ahould look into using a ceramic antenna chip instead of of a PCB trace antenna like these.

• https://resources.pcb.cadence.com/blog/2020-understanding-ceramic-chip-antenna-vs-pcb-trace-antenna

Recommend making an adapter that is optimized to act as a plug-and-play Zigbee Coordinator USB dongle and preferably do not skimp out of the ceramic antenna chip or the antenna filter component design to save money as Zigbee is extremly sensitive to RMI and EMF so proper antenna implementation is a must or else Zigbee users will have a bad exerience with it. For reference see:

• https://community.home-assistant.io/t/zigbee-network-optimization-a-how-to-guide-for-avoiding-radio-frequency-interference-adding-zigbee-router-devices-repeaters-extenders-to-get-a-stable-zigbee-network-mesh-with-best-possible-range-and-coverage-by-fully-utilizing-zigbee-mesh-networking/515752

[semaf]

We will use ESP32 modules instead of individual components. The reason is on the one hand because of the costs and on the other hand because of regulations in the EU. A PCB antenna is more efficient than a ceramic antenna, which is also present on the module. Ceramic antennas are often advantageous on very small developments as there is no space on the PCB. But a uFL connection will be available to attach an external omnidirectional antenna.

The idea of breaking off the board can also be implemented. We are trying to keep as much as possible smaller with the external components. If you guys are interested, I will be happy to share the test production with you.

[Hedda]

@semaf any updates on your USB dongle(s)?

[semaf]

Yes but need some updates.

[Hedda]

@semaf Nice! Will that be based on the ESP32-H2 or the ESP32-C6? Or do you maybe plan on making two seperate model variants?

If you like the idea of also making more advanced adapters and that way possible getting more people from the Home Assistant community involved then you could possibly even consider making another mora advanced adapter that follows a similar new design for the "Home Assistant Connect ZWA-2" (Z-Wave Adapter) that was just launched/announced/released yesterday and will soon be made available as open-source hardware:

• https://www.home-assistant.io/blog/2025/08/13/home-assistant-connect-zwa-2/

  • https://www.home-assistant.io/connect/zwa-2/

    • https://support.nabucasa.com/hc/en-us/categories/28669861145885

      • https://support.nabucasa.com/hc/en-us/articles/28689873798173-Home-Assistant-Connect-ZWA-2-Datasheet

I highly recommend watching their launch video regardless even if it is partially off-topic here:

• https://www.youtube.com/watch?v=Z-pUkM6XIuA&source_ve_path=Mjg2NjY

Funnily enough their circuit board for that ZWA-2 actually enough also uses a ESP32-S3 but currently that chip is only used as a basic Serial-to-USB bridge chip with a simpler open-source firmware insead of using a more common UART-to-USB converter chip (like example Silicon Labs CP2102 or WCH CH340), presumably just precisely because the alternatives are not running fully open-source firmware:

• https://github.com/NabuCasa/zwave-esp-bridge

While their previous Zigbee/Thread dongle, the Home Assistant Connect ZBT-1 (formally known as Home Assistant SkyConnect) is still just a small USB stick, this new Home Assistant Connect ZWA-2 Z-Wave Adapter is a massive 32 cm tall Z-Wave USB adapter, but that’s on purpose. Nabu Casa explains why:

"To be the most performant, we knew we had to ditch the “stick” form factor. It was never ideal, as USB ports can output a lot of interference. We even shipped a USB extender with Connect ZBT-1, and urged people to use it, as it kept the device away from any noisy components. Instead of building a stick we built an adapter, which includes an optimized standalone antenna and base that connects to your Home Assistant system with a USB cable."

Anyway, they said they plan on also releasing the full PCB design files, diagram and schematics for that ZWA-2 adapter as open-source too. but for now they only made specifications available, (as well as the hardware itself which is already for sale and in stock at retailers).

Home Assistant Connect ZWA-2 specifications:

• Model No.: NC-ZWA-9734
• FCC-ID: 2A8ZE05
• SoCs: Silicon Labs ZG23 (Z-Wave Controller radio MCU), and ESP32-S3 (USB-to-Serial bridge)
• Host interface, Power and data: USB-C, 5 V DC, 1 A (via USB-C female port).
• Supported protocols Z-Wave, Z-Wave Long Range
• Z-Wave series: 800
• Antenna characteristics:
  • Frequency range 860-930 MHz
  • Peak gain 3.38 dBi
  • Radiation pattern Omnidirectional (dounut shape)
• Range – Tested up to 1.5km (line-of-sight) by Nabu Casa
• Dimensions & weight Device:
  • 125x125x315 mm, 350 g
  • With box: 345x222x45 mm, 600 g
• Material
  • Enclosure:
    • Polycarbonate plastic
    • Colors: White and semi-transparent

[Hedda]

Funnily enough their circuit board for that ZWA-2 actually enough also uses a ESP32-S3 but currently that chip is only used as a basic Serial-to-USB bridge chip with a simpler open-source firmware insead of using a more common UART-to-USB converter chip (like example Silicon Labs CP2102 or WCH CH340), presumably just precisely because the alternatives are not running fully open-source firmware:

• https://github.com/NabuCasa/zwave-esp-bridge

By the way, I think it could in theory have been possivle to instead use ESPHome firmware on that ESP32 just as a Serial-to-USB bridge, because the ESPHome 2025.6.0 release version had implement USB Host mode UART via new "USB UART" and "USB Host" components to allow UART-to-USB converter capability features as well as supporting USB hubs. So maybe they did not use that for the new ZWA-2 only because ESPHome added that feature very recently (while the ZWA-2 has been in developent for years)?

• https://esphome.io/components/usb_uart

  • https://esphome.io/components/usb_host

    • [usb_uart] Implement USB Host mode UART esphome/esphome#8334