[BK7231N CB3S] Temperature and Humidity Sensor, TH01, PCB:ZY-TH02-CB3S, SHT3X

Again ordered Temperature and Humidity sensor from Aliexpress. Actually two of them.
I got one of this in ali. It is a device based on CB3S with a CHT8310? sensor and a Tuya chip.
Model: TH01
FCC ID: 2A8TU-TH01
PCB: ZY-TH02-CB3S_V1.0 (2024-12-03)


Case holes detail:


PCB detail:


HT Chip:


How it ended:


I wasn't able to put OBK on it using bk7231flasher_1.3.3. No reboot or CEN allowed me. So, I needed to desolder something.
For first device I tried desoldering the CB3S chip and my (lack of) soldering skills resulted in a lot of pads broken . But the CB3S survived and I was able to program OBK on it.
For second device I tried desoldering the Tuya chip, this time pads survived but still wasn't able to program it, therefore I needed to desolder the CB3S, this time all the pads survived.
Long story short, after several tries I decided to remove the Tuya chip and connect the CB3S directly to the supposed CHT8310. I assumed the PCB included a CHT8310 based on the picture of it and the fact the PCB literally has CHT8310 printed on it in some test points, specifically CHT8310_SDA, CHT8310_SCL and CHT8310_VDD.
To leverage the configuration I made to some other device I wired the CHT8310 chip to P9 and P6 of CB3S as per the pinout Here

When loading the driver I always get temp=125 hum=0, which means for me there is an issue with the communications.
Therefore I loaded the I2C driver and when I ran scanI2C soft I got

That is, as per my understanding the address of a SHT30 chip.
When trying to load that driver I realized it is not included in the current standard release of OBK, where can I get a version including SHT30 to see if that driver is capable of handling the chip?.

Looking at the pictures I would think it's no CHT8310 (the opening in the case is not centered as it seems on your sensor), so some SHT3x seems more likely.
I'll try to build a firmware including the driver.

Added after 14 [minutes]:

Here you go. Only compiled, not tested...

I knew deep in my box with sensors there was an SHT31

Looks like it should work:

do I only see 4 legs? It could be a CHT8320


https://www.elektroda.com/rtvforum/topic4095818.html

Added after 1 [minutes]:

if yes, the CHT83XX driver does not work for it

Yes, a clear picture of the sensor would be great.

While 0x44 is the default address for SHT3x, it's also possible on CHT8310:

See e.g. https://github.com/RobTillaart/CHT8310 :

The CHT8310 supports up to 4 devices on the I2C bus.

AD0	Address	Notes
GND	0x40	CHT8310_DEFAULT_ADDRESS
VCC	0x44
SDA	0x48
SCL	0x4C

yes and Info:I2C:Address 0x44 (dec 68) was the detection for my CHT8320

>>21452650 I uploaded new images for the chip the best I could and I can confirm, only 4 legs.

Added after 1 [hours] 14 [minutes]:

>>21451932 Tried your firmware and got

So it seems it actually is an SHT3x sensor or a clone. Good to know, maybe @divadiow this will solve your non functional device, too?

Added after 10 [minutes]:

At least your sensor seems very much the same device like the image above

But that's mad! Sensylink said it was a CHT8320...

Yes, they should know.
Maybe the protocol is kind of equal so it will give values if requested by the SHT protocol? The values at least look kind of sensible

weird. i must get to the bottom of this!


pins are correct. I get expected address with soft scan

Added after 27 [minutes]:

max4elektroda wrote:

So it seems it actually is an SHT3x sensor or a clone.

also weird. Sensirion SHT3x has 8 legs I thought and the logo in the pic is of Sensylink

divadiow wrote:

weird.

I couldn't find a better word for this.

I moved my LED connection to P8 to free the ADC3 pin, any advice on how to measure the battery voltage?

lktrdng wrote:

any advice on how to measure the battery voltage

Maybe take a look here

https://www.elektroda.com/rtvforum/topic3959103.html

it's about the "battery driver" which should do some kind of measuring on the ADC pin.
Only took a brief look, you will need a voltage divider if I got it right, but it seems to be doable to build a divider like shown here

https://www.elektroda.com/rtvforum/topic3959103.html#20588380

max4elektroda wrote:

So it seems it actually is an SHT3x sensor or a clone

https://github.com/pvvx/THB2/issues/1#issuecomment-2682896301

so yes. CHT832x is an SHT30 clone. Good to know a new driver doesn't need developing I guess

Hello, I have a few of these. Trying to to identify them is difficult when they're all called TH01 and then the PCBs are marked with all sorts of things. It is the same as the pictures in the first post. I have flashed OpenBeken 1.18.109 but I'm trying to get the configuration part correct. I'm looking at the OpenBeken web app config page, but cannot find the exact device in the drop-down list. Really I don't know what to do - I'm fairly new to this, but can see the device in HA. Many thanks for any help.

Ok, I finally found this in a large thread: https://www.elektroda.com/rtvforum/topic3968377-90.html#21420822

The device in the first post is a TuyaMCU battery powered device. It's a bit hard to convert, but it's supported by OBK, just as you linked.

There are also battery powered devices without TuyaMCU - they can use deep sleep mechanism. They are a bit more flexible. TuyaMCU battery powered can be converted to "deep sleep" battery powered device with some PCB changes, removal of MCU, etc. This can also work as long as the onboard sensor is supported by OBK itself.