[BK7231N] Aubess Mini Switch 16A

Pretoriano 11802 59

Cool? Ranking DIY | New topic

Notify about new articles

Helpful post? (+13)

#1 15 Aug 2022 17:24

This is a short teardown of the Aubess Mini Smart Switch 16A which is based on BK7231N and it uses a custom PCB ,so no Tuya module in there.

Basic Informations:

Brand: Aubess
Model: Aubess Mini Smart Switch 16A
Chip: BK7231N
Vendor (that's exactly where i bought it): https://www.aliexpress.com/item/1005003631131323.html? <- it's the kind of seller that ask for extra shipping fees,so not really recommend it

Teardown Photos

The switch is very easy to open so i wont go into details,but remember,this device it's using high voltage,so make sure it's not connected to the mains.Also ,i took pictures only of the relevant parts.

Flashing OpenBeken firmware

Requirements:

USB to TTL adapter
Soldering Iron
Soldering skils (not pro level,but still...)
Magnifying glass or microscope are a plus
Steady hands

Wiring: -> Check the attached picture to locate the pins on the PCB

( PCB ) GND - > GND ( TTL )
( PCB ) TX - > RX ( TTL )
( PCB ) RX - > TX ( TTL )
( PCB ) CEN/EN -> GND ( PCB ) <- CEN must be short to GND only for a second,in order to boot the chip in flash mode

Flashing: -> In my case the 3.3v pin was not required at all.

1) Connect GND,RX and TX to the USB TTL then attach the TTL adapter to the PC.
2) Open BKwriter 1.60 and set the baudrate (see attached picture)
3) Try to read the flash (if it fails ,then short CEN to GND for a second then try again) <- this will create a backup of the original firmware
4) After BKwriter has finished the backup,you can proceed with the OpenBeken firmware flashing ,just follow the guide from https://github.com/openshwprojects/OpenBK7231T_App/blob/main/README.md#flashing-for-bk7231n
5) After flashing Openbeken you should be able to find the quick configuration (i've sent a PR for that) for this device in ; http://[Device_IP] > Config < Quick Config

Cool? Ranking DIY
About Author
Pretoriano Pretoriano

Level 2
Offline

Joined: 07 Aug 2022

Posts: 2

Posts rating: 13

Points: 111
Pretoriano wrote 2 posts with rating 13. Been with us since 2022 year.
#2 16 Aug 2022 11:15

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#2 16 Aug 2022 11:15

That's a very informative and helpful teardown. Futhermore, from what I see at the moment:

The shipping to Poland is free and device is seemingly for only 25PLN (it's about 5$), so it's not that expensive. Of course, we also might need to take that new VAT tax into account...
#3 16 Aug 2022 11:49

Pretoriano Pretoriano

Level 2

Topic author Helpful post? (0)

#3 16 Aug 2022 11:49

It was "free shipping " when i bought it too,but the seller asked for €0.50 more as extra shipping fee.
However ,i had an Aliexpress coupon so it was still convenient ,that's why i agreed to pay that extra fee (i usually refuse to pay extra fees )
#4 30 Oct 2022 17:54

zopieux zopieux

Level 2

Helpful post? (+2)

#4 30 Oct 2022 17:54

I bought a bunch of these devices from Aliexpress. They're branded as Aubess but use a different pin configuration than the ones already documented in this thread.

The small BK7231N-supporting board seems to be this TCB2S thing from Trolink.

I managed to flash it using the UART (serial) method (therefore, QIO firmeware variant), following the usual BK7231N UART flashing guides from this forum (uartprogram) on the RX1/TX1 un-soldered pins. Happy to report OpenBK7231T_App QIO firmwares work just fine!

Pin configuration: P6 is the internal button, P7 is the blue LED, P24 is the internal relay, P26 is the switch/toggle sensing on screw terminals S1 & S2. I'm sending a PR to add this variant.
#5 10 Nov 2022 21:34

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#5 10 Nov 2022 21:34

Hello,

I'm trying to just read the firmware on a CB2S, see the picture

However, I just get Speed of Programm:115200bps Init...FAILED

Could be the programmer? I'm using this:

https://www.amazon.co.uk/gp/product/B07BBPX8B...=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Any idea?

Thnaks!
#6 10 Nov 2022 21:50

kuba2k2 kuba2k2

Level 12

Helpful post? (+1)

#6 10 Nov 2022 21:50

Here's a guide for dumping the Beken chip:

https://docs.libretuya.ml/docs/platform/beken-72xx/dumping/

Using BkWriter is always discouraged, as it is very unstable. Use bk7231tools as instructed.
#7 11 Nov 2022 11:57

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#7 11 Nov 2022 11:57

Hello,

Thanks for the reply, I have done the program using the command line tool, all went fine but...nothing is working. I have solded the module back and the blue led just stay still, no wifi network, no activity. My question is, how can I check what is happening, is there any terminal output I could check to see what the issue is?

Thanks,

Ciclope
#8 11 Nov 2022 12:49

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#8 11 Nov 2022 12:49

You may have flashed the incorrect binary file. Log output is available at TX2 pin. It should tell you what is happening.
#9 16 Nov 2022 20:20

vladimir5 vladimir5

Level 1

Helpful post? (0)

#9 16 Nov 2022 20:20

Thanks for this overview!
I have exactly the same module from aliexpress. Everything is working fine except s1-s2 contacts. There is no effect if I short/open them. (no matter what mode is chosen in the app)

Probably there is some problem on the board?
Mine has 65 Ohm resistance between S1 and S2 contacts.
And S1 is short to Nin/Nout.

Could you please check yours?
#10 23 Nov 2022 11:52

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#10 23 Nov 2022 11:52

Hi,

Not sure I understand your message but I think I have the same issue.

I was able to flash it correctly, however, I can only control the led with the interface, the swicth do not work:

Let me know if you have the same issue and if you have found a solution.

Thanks,

Cilcope

.....

vladimir5 wrote:
Thanks for this overview!
I have exactly the same module from aliexpress. Everything is working fine except s1-s2 contacts. There is no effect if I short/open them. (no matter what mode is chosen in the app)

Probably there is some problem on the board?
Mine has 65 Ohm resistance between S1 and S2 contacts.
And S1 is short to Nin/Nout.

Could you please check yours?
#11 23 Nov 2022 12:19

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#11 23 Nov 2022 12:19

Why is the Relay not set for pin 26? Is there some issue with the template?

Please try manually entering Relay for pin 26.
#12 23 Nov 2022 12:58

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#12 23 Nov 2022 12:58

I did but still nothing, the led go off and on when I click on/off in the web interface, but not the relay.

I was wondering, if the LED is going on and off according to the commands I give using the web interface, is that telling me that all physical pin connections are good or is the led controlled using a different physical pin than the relay? just asking also because I have concerns about the pin marked as p6 be able to connect properly to the board..

p.kaczmarek2 wrote:
Why is the Relay not set for pin 26? Is there some issue with the template?

Please try manually entering Relay for pin 26.
#13 23 Nov 2022 13:12

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#13 23 Nov 2022 13:12

If LED is going on and off then it means that you don't have configured relay correctly. Maybe relay is on some other pin. Maybe take some HD photos and show us the board, or check where the base of transistor switching on the relay goes? Remember that there will be also a resistor on the way.

In the device template you shown above, LED is using different pin than relay. LED is on pin 8. So the question is... on which pin is the relay?

In worst case, you can try setting them one by one and checking if it clicks....

ALSO.... please remember, if you are powering the device from 3.3V from your own 3.3V supply, then relay might NOT click because relay is powered usually from 5V on the board!!!
#14 23 Nov 2022 13:34

ciclopeblu ciclopeblu

Level 4

Helpful post? (+1)

#14 23 Nov 2022 13:34

This is the board:

It looks pretty similar to the one on the app template.

I have solded the module back so the volts powering the relay should be ok, I assume?

Which one is the base of transistor switching?
#15 23 Nov 2022 14:23

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#15 23 Nov 2022 14:23

U2 is the 3.3V LDO, so Q1 is most likely the transistor.

Please check where it pins goes, one should go to Relay, and second one should go to WiFi module pin - check which pin.
#16 23 Nov 2022 14:55

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#16 23 Nov 2022 14:55

From Q1 :

- middle pin is going to the switch (it can be seen also from the picture)
- Left pin is going to GND
- Right PIN doesn't go straing to any pin in the module, it goes to rp2 and then P26
#17 23 Nov 2022 16:04

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#17 23 Nov 2022 16:04

Can you go to Options, Configure Module and show what do you have here:

?
Post a screenshot
#18 23 Nov 2022 16:14

ciclopeblu ciclopeblu

Level 4

Helpful post? (0)

#18 23 Nov 2022 16:14

Mate,

Apologies, just replaced the board with another one and everything isa working fine! it was a defective board, the wifi module is perfect.

The template needs to ne updated though adding the pin26.

Other question, is any way to make the Power meter reading to work?

p.kaczmarek2 wrote:
Can you go to Options, Configure Module and show what do you have here:

?
Post a screenshot
#19 23 Nov 2022 16:36

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#19 23 Nov 2022 16:36

Board was defective? How? That's good if it works now.

What kind of power meter? We are currently supporting BL0937, BL0942 and CSE*.
#20 15 Jan 2023 12:07

jorgemsp jorgemsp

Level 2

Helpful post? (0)

#20 15 Jan 2023 12:07

Hi everyone,

I've been exploring the flashing of those devices and the its operation with OpenBK7231N.
I'm noob on this field so I apolagize in advance for any basic question I can place.
I've used tuya-cloudcutter and OpenBK7231N to flash my AUBESS mini with success and I'm currently able to switch the relay though local network.
What I've noticed is that the relay works fine but the LED is allways ON in what it seems an intermediate state (slightly dimmed). I've configured exactly like in the picture shared in one of the posts of this thread.
Any idea how could I solve this problem? (not really important, but it would help me to better understand the device)
Additionally, this device has two versions: w/power metering or w/o power metering.
Any idea on how to configure/enable the power metering?

Thanks in advance for any assistance!
#21 15 Jan 2023 12:56

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#21 15 Jan 2023 12:56

What kind of the device?
LED could be on another pin, manufacturers tends to change it from time to time.
Maybe you should try looking at PCB tracks or just guessing each pin one by one - if that's a WB2S/CB2S device, there is no many options. Just set each pin role to LED and mark as channel 2 and try toggling and see which pin makes the LED toggle.

What kind of power metering device is inside? BL0937? BL0942?
#22 16 Jan 2023 00:18

jorgemsp jorgemsp

Level 2

Helpful post? (0)

#22 16 Jan 2023 00:18

p.kaczmarek2 wrote:
Maybe you should try looking at PCB tracks or just guessing each pin one by one - if that's a WB2S/CB2S device, there is no many options. Just set each pin role to LED and mark as channel 2 and try toggling and see which pin makes the LED toggle.

I was going to start changing pins and noticed that actually it was my mistake... I've assigned to P9 instead of P8...

p.kaczmarek2 wrote:
What kind of power metering device is inside? BL0937? BL0942?

It is the BL0942:

The BL0942 datasheet confirms that the IC incorporates two ADC's for current measurement (pins 2,3 of the IC - differential, coming from the sensing resistor) and votage (pin 4 of the IC from the resistor divider on the right part of the picture).
Any tips on how should I iterate to find those measurements, if possible? (Energy and/or power should also be available though estimation)
#23 16 Jan 2023 10:00

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#23 16 Jan 2023 10:00

For BL0942, you just do a "startDriver BL0942" in short startup command, reboot, and then use VoltageSet/CurrentSet/PowerSet commands to calibrate..
#24 17 Jan 2023 00:32

jorgemsp jorgemsp

Level 2

Helpful post? (0)

#24 17 Jan 2023 00:32

Following your advice and after reading your previous post: https://www.elektroda.com/rtvforum/topic3887748.html
I'm finally reading accurate measurements of Voltage, Current and Power!
I'll now keep digging and try to connect it with HA.
Thank you very much for the hints and congrats for all your work,
#25 17 Jan 2023 09:16

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#25 17 Jan 2023 09:16

@jorgemsp thanks, as far as I know, the Home Assistant Discovery is already working for Current, Power and Voltage. So it can be paired with one click. @iprak may know more about it, as he's the author of HASS Discovery support for OpenBK.
#26 20 Jan 2023 21:25

bernardstef bernardstef

Level 1

Helpful post? (+1)

#26 20 Jan 2023 21:25

Hi !!

Just to add to Pretoriano post. I have the exact same board, model is AVATTO , WSM02 (5€ on Aliexpress)

Thanks you for the TX/RX Pins !!

"Easy config" is depreciated. Pins are:

p6 led

p15 relay

p14 pin s1-s2

p8 btn on pcb

Cheers and thanks !
#27 24 Jan 2023 14:01

khafif khafif

Level 3

Helpful post? (0)

#27 24 Jan 2023 14:01

Hi, you said that the 3.3v pin was not required at all, did you use the AC (Lin-Nin) connection to power the PCB? or you just connected it to TTL using TX,RX and GND?
#28 24 Jan 2023 15:23

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#28 24 Jan 2023 15:23

@khafif do not power device from mains while flashing! It's very dangerous!

Please always power it from a 5V (if you solder wire to 5V rail, before the LDO regulator that gives 3.3V for WiFi module) or from 3.3V directly.

The only case where you do not solder VDD is when you have a 9V/12V/etc LED strip and in that case you might power it from an isolated 9V /12V etc DC supply...

But WiFi module must have 3.3V for flashing to work!
#29 24 Jan 2023 16:55

khafif khafif

Level 3

Helpful post? (0)

#29 24 Jan 2023 16:55

Thank you my friend for the advice not powering it while flashing and that is why i asked you about the power supply.

I will use the USB/TTL VCC 5V/3.3V provided to power the WiFi module during the flashing.

Please can you mark on the above screenshots where do I have to connect the 3.3v on the WiFi board. I am not familiar with the terminology of LDO and where it is location.

Thank you again.
#30 24 Jan 2023 17:07

p.kaczmarek2 p.kaczmarek2

Moderator Smart Home

Helpful post? (0)

#30 24 Jan 2023 17:07

khafif wrote:
Thank you my friend for the advice not powering it while flashing and that is why i asked you about the power supply.

Sorry but where is the post with "do not power the device" advice? It must have been a mistake or typing error. I will edit that.

khafif wrote:

Please can you mark on the above screenshots where do I have to connect the 3.3v on the WiFi board.

Which device and which module?

khafif wrote:

I am not familiar with the terminology of LDO and where it is location.

5V goes in, 3.3V goes out.

Maybe try our video guide?
https://www.youtube.com/watch?v=PKkiqDNFIx8
Create an account, log in and become active in a forum and ads will not appear. You will receive points by participating in discussions.
Join this discussion.

Log in with Google

Cool? Ranking DIY | New topic

Notify about new articles