3A Wi-Fi Smart Light Dimmer Switch - flashing with tasmota

I’ve got myself one of the 3A dimmer switches because it has a template listed on the Tasmota Device Templates Repository

On that page it shows that re-flashing with tasmota is possible with Tuya-convert. I’ve always had mixed success with Tuya-convert but this time I am a bit stumped as I haven’t been able to put the dimmer switch OTA upgrade mode.

Just wondering if anyone here has flashed a HGZB-04D wifi dimmer switch and if so, what did you do to get it into upgrade mode? (LED flashing quickly).

Hi there!

Funnily enough I was just able to get this to work this morning.


These devices use the new firmware and an external MCU so it is a little complicated and requires some soldering. OTA will not work at all.

The relevent information that led me to the solution:

  1. Identify the chip which is a https://tasmota.github.io/docs/devices/TYWE3S/
  2. Identify there is an external MCU - http://www.datasheetcafe.com/bs003f3p6-datasheet-8s003f3p6-microcontroller/
  3. Ground the correct pins to put it into flashing mode
  4. Success

To get it into flashing mode you have to connect it all to the external FTDI (I use the FTDI FT232.

Then you need to ground the GPIO Pin0 on the TYWE3S to ground, keep this connected until the end

Then you need to ground the RST pin from the 8s003f3p6 as well, this stops the MCU from taking over the TX/RX pins. You will notice that when you power the FTDI, all the LED’s will come on, when you ground the RST pin, only the middle LED will be on, but dim. I just held it there with some clips during the flashing process.

Once all this is done, you can go ahead and flash Tasmota as per the instructions.

I’m at work right now but when I get home I’ll put a photo instruction set up on GitHub.

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Awesome… Thanks @HoustonAU for your info. Something new to try… :partying_face:
I’ll try that out and report back… might be a couple of days though :wink:

I would be helpful for others if you also posted this in the Australian Electrically Certified Hardware thread.

I have been able to successfully flash my dimmer with the information posted by HoustonAU… thanks again.

@kanga_who, I have created a pull request to update the information on the Tasmota templates page. Happy to post to Australian certified hardware threat once my pull request has been merged.


I know this is old but I’ve been out of the loop for a while. Great to know you were able to get it going!

Thanks a lot for this, just flashed my dimmer, used the guide at 3A Smart Home HGZB-04D Dimmer (HGZB-04D) Configuration for Tasmota to help as well.

Was unsure how to set the TuyaMCU type and dimmer range, eventually found out I had to copy these lines separately into the console.

TuyaMCU 21,2
DimmerRange 11,255

Thanks a lot, keep up the good work.

Note: I also tried Tuya Convert many times it did not work.