Treatlife DS03 Smart Dimmer / Fan controller - Absolute beginners guide to flashing (On a Mac)

mitmit17 19 Jun 2023 20:44 18 5052 Cool? (+3)

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TL;DR

Flashing the Treatlife DS03 Smart Dimmer/Fan controller from Tuya firmware to OpenBeken for direct Home Assistant integration on a Mac.
The process opens the DS03, solders 3.3V, GND, nRESET, TX, and RX to the WB3S UART, then flashes with bk7231tools over USB-to-TTL.
A stubborn board required restarting the WB3S by momentarily shorting CEN to GND while bk7231tools was already flooding the serial link.
It backs up the original firmware, writes OpenBK7231T_UA_1.17.147.bin at offset 0x11000, then configures Wi‑Fi, MQTT, autoexec.bat, and Home Assistant.
The USB-to-TTL adapter may reset itself during the CEN-to-GND trick, so a separate 5V supply and careful tapping are recommended.

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I recently purchased a couple of Treatlife DS03 Smart Dimmer / Fan controller.
Naturally, I had no desires to use the Tuya cloud services and wanted to connect it directly to my Home Assistant setup.

There were many guides that one could find, but none of them was complete (using phrases like "do it in the usual way"). As someone new to both HA and OpenBeken world, I've had some trouble getting a definitive answer on how to get the process across. To make matters worse, I only have a Mac machine so all the windows flashing guides weren't very usable for me
After some trial and error and time spent on research, I've decided to put down the following guide for prosperity. Hope someone finds in useful in the future.

1. Disassemble the board
Open the four screws connecting the face plate and carefully pry open the panel (which contains the WB3S board)

2. (Optional) Remove board with WB3S board from buttons
Remove 3 small screws and disconnect main board from panel (marked above in red)
You should end up with the following board (both sides shown below)

3.Soldering wiring and pins
In order to flash OpenBeken on this chip we're going to need to use the UART interface of the WB3S board. However this interface is already used by the Tuya software to communicate with the Tuya MCU (Novton board on opposite side) that's actually controlling the leds and GPIOs.
So we need to expose the UART wires and reset the MCU so that we can chat without interruption

Solder pins / wires on the 3.3V, GND, nRESET, TX & RX lines, marked below

Solder the pins

Solder the wires

If you're not experienced in soldering, verify all the connectivity with a multimeter.

4. Connect to USB-to-TTL board
I'm using this board and use the following connections. Notice that RX on the board is TX on the USB-to-TTL and vice versa.

DS03 Mainboard	USB-to-TTL
3.3v	vcc
GND	GND & NRESET
TXD	RXD
RXD	TXD

Note, in order to connect the USB-to-TTL GND to both GND and NRESET, I used a small breakout board as seen below

And connect the USB-to-TTL to your computer (my MBP in my case)

5. Install python and install the bk7231tools package so we can flash the firmware
We're going to install the bk7231tools package to support flashing

6. Check connectivity and see if we're able to communicate with the board

7. What happens if the above fails (usually timeout)
In some of the boards the above worked without issue, while in another board I could not get the above to work at all. The problem seems to have been that the Tuya app was trying to talk over the UART with the MCU (which is held at reset) and would only give a small time window at boot time to talk with the bootloader.
The solution comes from reseting the board while the python script was already running (the bk7231tools script is internally flooding the serial).
Reseting is done by shorting the CEN pin on the WB3S board to GND. However the USB-to-TTL board I've had didn't appreciate the" "short" here and reseted themselves (disconnecting the USB).
The below describes what one can do if that happens:

7.1 Use a separate 5V power source and connect it to the 5v connectors as marked below. Disconnect the 3.3V source from your USB-to-TTL converter. In my case I used another USB-to-TTL with the jumper set to 5V. Do not use TX/RX on this device as it may damage the WB3S.

7.2 Run the bk7231tools command as above and while it waits, tap connect the GND to the CEN pin as marked below (to reset the WB3S) board. See below on locations. I connected another connection to the breakout board connected to GND and used the other side of the wire to momentarily tap the wire on the CEN pin, quickly reseting the board.

7.3 The python script should work now as expected

8. (Optional) Create a backup of your existing firmware

9. Write new firmware on the device
Download the relevant OpenBeken image from OpenBK7231T github page. Use the UA version (UART firmware). At the time of this writing the the file I used was OpenBK7231T_UA_1.17.147.bin

Use the following commands to write (notice we're using the offset of 0x11000 which is after the bootloader)

Success! Our WB3S is now using OpenBeken!

10. Disconnect all but the 5V power and 5V GND

[b]11. Configure the OpenBeken software to connect to your wifi
Connect your computer to the OpenBeken SSID and browse to 192.168.4.1
Configure the wifi details

Restart the WB3S and connect to it's IP address (use your router's interface to find it)

12. Configure names and MQTT parameters

And it should connect to MQTT in your setup

13. Write an autoexec.bat file
Click Launch Web Application and click on Filesystem
Create a file called autoexec.bat and set it's content to

Reboot
The firmware should now look like this

14. Connect to Home Assistant.
You can either create an MQTT discovery through OpenBeken (Config->Home Assistant Configuartion) or use the following in HA

15. Unsolder the wires and pins from the board
And put everything back together

Congrats.[/b]

About Author

mitmit17 wrote 3 posts with rating 4 , helped 1 times. Been with us since 2023 year.

Comments

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p.kaczmarek2 20 Jun 2023 12:26

Very good and detailed guide. Here are few more tips from me: - you can use SSDP driver to get your device discoverable by Windows (startDriver SSDP in autoexec.bat) - you can use power save to lessen... [Read more]

mitmit17 20 Jun 2023 18:40

Awesome. Thanks! [Read more]

mitmit17 28 Jun 2023 00:31

I found that the OpenBeken heuristics for Home Assistant discovery isn't great for this device. It creates the fan switch as a light switch, ignores the fan speed setting. I wasn't happy with it. The... [Read more]

p.kaczmarek2 28 Jun 2023 01:43

Very good job. I am planning to customization option for OBK hass automatic discovery, maybe that could also help in the future. It will be most likely possible through our Web App. [Read more]

xSPARExSTEWx 06 Aug 2023 04:26

Just as an FYI for any one else looking into these. I bought both a single and the 2 pack off of amazon. The single pack had the BK7231T chip, but the 2 pack had the BK7231N chip. Not sure how different... [Read more]

p.kaczmarek2 06 Aug 2023 07:43

Do you have flash backups for both N and T versions? Can you submit them here? [Read more]

xSPARExSTEWx 06 Aug 2023 09:10

Yes I do! Hopefully they attached correctly. [Read more]

kaplanroger 07 Oct 2024 02:57

I just experienced this too. There are three boards inside on top of each other and they're all soldered together. I removed the two screws on the metal faceplate and wiggled the assembly out. In order... [Read more]

p.kaczmarek2 07 Oct 2024 08:07

28 pin DIP MCU, are you sure? That would be a very large case, as for Tuya device... https://obrazki.elektroda.pl/5771956700_1728281264_thumb.jpg [Read more]

kaplanroger 07 Oct 2024 12:24

Well not technically a dip but rectangular with pins on 2 sides https://obrazki.elektroda.pl/1698324000_1728296627_thumb.jpg Note how the 5th pin on the top has no trace, that’s the reset pin. ... [Read more]

p.kaczmarek2 07 Oct 2024 15:48

So a TSSOP28 case. That is very possible. DIP28 is not used in smart devices at all. [Read more]

kaplanroger 09 Oct 2024 00:31

I removed the module (CB3S) using the heat gun approach and programmed it with OpenBK. I used this $5 thingy for the programming: https://www.aliexpress.us/item/2251832626534341.html Although it's for... [Read more]

kaplanroger 10 Oct 2024 03:51

I reassembled everything and fired it up. I'm having trouble with some Openbk stuff which I'll put in another post, but I did discover that the light power DP is 101 and light dimmer DP is 6, which is... [Read more]

hubertwinny33 10 Oct 2024 15:45

I came across this too where the boards were literally soldered together so that you couldn't pull them apart and flash them. Why are these guys such jerks? [Read more]

kaplanroger 10 Oct 2024 18:39

I suspect it has to do with ease of assembly. If you're going to solder a header socket, might as well solder the header and remove the manual insertion process which probably bent pins. Anyway, I finally... [Read more]

vdubs22 25 Nov 2024 23:47

Were you able to get this working? Is there a way to flash this without removing CB3S from main board? [Read more]

kaplanroger 26 Nov 2024 03:37

No because I unsoldered the board and flashed it in isolation. However I gave up on the device because the Tx->Rx trace between the BK chip and the MCU somehow got broken, and while removing the... [Read more]

vdubs22 26 Nov 2024 04:36

Thanks for detail description. I will give this a try [Read more]

FAQ

TL;DR: For 15-step Mac flashing, "use the UA version" of OpenBeken, wire 3.3V, GND, TX, RX and hold TuyaMCU reset before using bktools on /dev/cu.usbserial-XXXX. This FAQ helps Home Assistant beginners flash Treatlife DS03 without Tuya cloud. [#20623613] Why it matters: Treatlife DS03 hardware varies, so the correct chip, reset method, firmware image, and DPIDs prevent failed flashing or broken fan control.

DS03 variant or method	Module or chip	Practical flashing note
Original guide unit	WB3S / BK7231T	Use OpenBK7231T UA firmware at offset `0x11000`.
Later 2-pack unit	BK7231N / CB3S reported	Use the correct N build, not the T build.
Soldered-board unit	CB3S hard to access	Remove or clip the module; boards may need desoldering.
Windows alternative	BK7231 GUI flasher	Optional GUI route instead of Mac `bktools`.

Key insight: Do not treat every Treatlife DS03 as the same board. Confirm BK7231T versus BK7231N, then verify Tuya DPIDs before final Home Assistant MQTT discovery.

Quick Facts

The core UART wiring is four logic connections: DS03 3.3V to adapter VCC, GND to GND, TXD to RXD, and RXD to TXD; the MCU reset line also ties to ground during flashing. [#20623613]
The Mac command bktools chip_info -d /dev/cu.usbserial-XXXX returned BK7231S_1.0.5, Protocol: BASIC_TUYA, and confirmed bootloader communication before writing firmware. [#20623613]
Full Tuya backup used read_flash from address 0 with length 0x200000, equal to 2,097,152 bytes. [#20623613]
The OpenBeken write example used start offset 0x11000, wrote 978,944 bytes, and finished with CRC verification OK!. [#20623613]
Later DS03 units can have three stacked boards soldered together, a Nuvoton M031EC1AE in TSSOP28, and reset on pin 24. [#21320055]

How do I flash OpenBeken onto a Treatlife DS03 Smart Dimmer/Fan Controller using a Mac?

Flash it with bk7231tools, a USB-to-TTL adapter, and the OpenBeken UART image.

Disassemble the DS03 and expose WB3S UART pads.
Install Python support with pip install bk7231tools.
Run bktools chip_info, back up flash, then write the UA image at 0x11000.

After flashing, power the board, join the OpenBeken SSID, browse to 192.168.4.1, and enter Wi-Fi details. The guide used /dev/cu.usbserial-XXXX on a MacBook Pro. [#20623613]

What wiring connections are needed between the Treatlife DS03 WB3S board and a USB-to-TTL adapter for UART flashing?

Connect power straight and cross the UART data lines. Wire DS03 3.3V to adapter VCC, DS03 GND to adapter GND, DS03 TXD to adapter RXD, and DS03 RXD to adapter TXD. Also connect DS03 GND to NRESET to hold the Tuya MCU silent. The thread used a small breakout board to split USB-to-TTL ground to both GND and NRESET. Verify continuity with a multimeter if soldering is new to you. [#20623613]

Why does bk7231tools time out when trying to read chip_info from a Treatlife DS03, and how can I reset the WB3S with the CEN pin?

bk7231tools times out when Tuya firmware occupies the UART before the bootloader responds. Start bktools chip_info first, then momentarily short WB3S CEN to GND to reset the module while the script floods serial. If the USB-to-TTL adapter resets during that short, power the DS03 from a separate 5V source and disconnect adapter 3.3V. Do not use TX/RX on the separate 5V device, because it can damage the WB3S. [#20623613]

Which OpenBeken firmware file should I use for a Treatlife DS03 with a BK7231T chip versus a BK7231N or CB3S module?

Use the OpenBeken build that matches the actual chip family. For the BK7231T guide unit, the author used the OpenBK7231T UART image, specifically the UA version, with an example file named OpenBK7231T_UA_1.17.147.bin. A later buyer found a single pack with BK7231T, but a 2-pack with BK7231N. That means the N unit needs the correct BK7231N/OpenBeken image, not the T file. [#20682744]

How do I back up the original Tuya firmware from a Treatlife DS03 before flashing OpenBeken?

Back it up with bktools read_flash before writing OpenBeken. The example command reads from start address 0 for length 0x200000 into dump_full.bin. That equals 2,097,152 bytes of flash data. Run bktools chip_info first to confirm the device answers over /dev/cu.usbserial-XXXX. Keep the backup file before writing the new image at offset 0x11000. [#20623613]

What should go in the OpenBeken autoexec.bat file for the Treatlife DS03 fan, light, dimmer, and TuyaMCU channels?

Put NTP, TuyaMCU, channel types, and DPID links in autoexec.bat. The guide starts NTP, then starts TuyaMCU, sets Wi-Fi state 4, and sets baud rate 115200. It maps light power to channel 1, dimmer to channel 2, fan power to channel 3, and fan speed to channel 4. Original DPIDs were 9 for light power, 10 for dimmer, 1 for fan power, and 3 for fan speed. [#20623613]

Why do some Treatlife DS03 units use different Tuya DPIDs like light power DP 101 and dimmer DP 6 instead of DP 9 and DP 10?

Different DS03 hardware revisions use different Tuya MCU data point mappings. One later CB3S-based unit reported light power on DPID 101 and light dimmer on DPID 6, not 9 and 10. Replace the 9 and 10 values in linkTuyaMCUOutputToChannel for that revision. Keep fan DPIDs unchanged only after verifying logs or behavior. [#21257276]

How can I configure Home Assistant MQTT discovery correctly for the Treatlife DS03 fan speed and light dimmer?

Publish custom MQTT discovery payloads for separate fan and light entities. The working script created homeassistant/fan/${device_name}_fan/config and homeassistant/light/${device_name}_light/config. It mapped fan state to ~/3/get, fan command to ~/3/set, speed state to ~/4/get, and speed command to ~/4/set. It mapped light state to ~/1/get, light command to ~/1/set, brightness state to ~/2/get, and brightness command to ~/2/set. It also used retained mosquitto_pub messages. [#20633564]

Why does OpenBeken Home Assistant auto-discovery create the Treatlife DS03 fan switch as a light and ignore fan speed?

OpenBeken’s automatic Home Assistant discovery heuristics misclassify this DS03 configuration. The author found it created the fan switch as a light switch and ignored the fan speed setting. The fix was to publish manual MQTT discovery messages that define the device, fan, light, speed percentage, presets, availability, and retained configuration topics. This creates a real MQTT device in Home Assistant, not only loose entities. [#20633564]

What is TuyaMCU and why does the Treatlife DS03 need it after flashing OpenBeken?

"TuyaMCU is a serial control layer that lets OpenBeken communicate with the separate Nuvoton microcontroller, keeping fan, LED, dimmer, button, and GPIO behavior available after replacing Tuya Wi-Fi firmware." The DS03 WB3S uses UART to talk to the Tuya MCU on the opposite board. OpenBeken must start TuyaMCU and set 115200 baud so commands reach that controller. [#20623613]

What is the CEN pin on a WB3S or CB3S module and how is it used during flashing?

"CEN is the module reset input that restarts the WB3S or CB3S Wi-Fi module, allowing the bootloader window to open while flashing tools are already polling UART." During a timeout, momentarily connect CEN to GND. One ESP-style programming board also had a reset button that bridged CEN to ground for CB3S flashing. [#21255989]

BK7231T vs BK7231N in Treatlife DS03 switches — what are the practical differences when flashing OpenBeken?

The practical difference is firmware selection. A reported single-pack DS03 used a BK7231T chip, while a 2-pack used a BK7231N chip. Flashing requires the OpenBeken build for the installed chip. Do not assume all DS03 units match the original WB3S/BK7231T guide. Confirm the module marking before writing, because the wrong image targets the wrong Beken family. [#20682744]

How can I flash a Treatlife DS03 when the faceplate boards are soldered together and the CB3S module is hard to access?

Use desoldering or external clips instead of forcing the stacked boards apart. One later unit had three boards stacked and soldered together. The user removed two metal faceplate screws, flexed the assembly, removed three small screws, desoldered an 8-pin header, and then removed the CB3S module. Another approach used a heat gun and a $5 ESP-style programming fixture to flash the CB3S outside the DS03. [#21255989]

How do I use IC test clips on the Nuvoton M031EC1AE TSSOP28 MCU to hold nReset low while flashing a Treatlife DS03?

Clip onto pin 24 of the Nuvoton M031EC1AE TSSOP28 and connect it to ground. Put the package dot at the upper left as pin 1. Count pins counter-clockwise; pin 24 is the fifth pin from the top on the right side. TSSOP-compatible IC test leads can also clamp to TX/RX solder blobs near the BK module, reducing tiny-pad soldering. MCU pins 3 and 4 carry TX/RX to the BK board. [#21320055]

How can I troubleshoot a Treatlife DS03 where TuyaMCU packets from the MCU appear in OpenBeken logs but commands sent from MQTT or the web app do not control the device?

Check command syntax, DPID mapping, and the physical TX-to-RX path. One user found inline // comments after linkTuyaMCUOutputToChannel commands stopped DPID binding; moving comments to separate lines helped. Later, logs showed MCU-to-OpenBeken packets, but no effective commands back to the device. The same unit eventually had a broken TX-to-RX trace between the BK chip and MCU. Verify continuity before further software changes. [#21258011]

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