On-PCB BK7231N TH01 Battery Temp/Humidity Sensor with SHT30 Sensor - Another Variant

Hi

I won't go mad with detail because it's just another TH01 type battery temperature/humidity sensor that other threads can be consulted on for more intimate detail on this kind of device. Posting so this can be another +1 for the device list.

This one appears to vary in that it has no module. The BK7231N is soldered directly to the PCB and is accompanied by an SHT30 temperature and humidity sensor.



The test pads are



The two unlabelled in the middle are two of these 4 I believe



which means there is no readily available UART2_TXD for the output log. The underside of the PCB is plain but for a ground pad.

Dump attached. Firmware version 1.1.17, which looks to be cloudcuttable. Extracted pin assignments:



and the user params



The presence of "net_led_pin":"26" in the json but not in the plain text assignment list means Easy Flasher forgot to include P26 for the WifiLED.

It's good to see the new additions showing



which means we assign the SHT:


The alert pin is not yet usable.

basic autoexec to config battery:



P20 button swapped for DoorSnsrWSleep so the button can wake the device from deep sleep.

I see the pin assignment is the same as this device https://www.elektroda.com/rtvforum/topic3945688.html but that has a CBU module and the user has set "16": "dInput" for the alert pin, not sure if this does anything.

Added after 3 [minutes]:

https://github.com/OpenBekenIOT/webapp/pull/121

That's a nice discovery, I haven't seen any such sensor (door/humidity/water) with BK7231 directly on PCB. Is that yet another method used to reduce costs by Tuya?

A reasonable assumption

Hi and congratulations for your excellent work.

I've a problem with a sensor, it's like the one posted in the first message.
It doesn't show temperature nor humidity.
I've flashed it with openbeken, last version. It shows battery percentage, although I'm feeding it with a lm1117.

In the log is showing a clear message that states: "Info:MAIN:Driver SHT3X is not known in this build."

Is there a way to test if sht30 isn't damaged? I'm not using this sensor for a few months, without batteries.

This is the startup command:
addEventHandler OnClick 20 startScript this runmeas 456

init:
echo "Init driver and powersave "
startDriver TuyaMCU
setChannelType 3 toggle
setChannelType 1 temperature_div10
setChannelType 2 humidity

again:
echo "activate SHT3X Sensor"
startDriver SHT3X
setChannel 3 1
echo "Send some measure"
delay_s 2
echo "stop SHT3X driver"
stopDriver SHT3X
setChannel 3 0
echo "wait 10min"
delay_s 10
goto again

runmeas:
// stopScript ID bExcludeSelf
// this will stop all other instances
stopScript 456 1
echo "Force measurement"
startDriver SHT3X
setChannel 3 1
delay_s 2
stopDriver SHT3X
setChannel 3 0
echo "go back to loop"
goto again;

For now I'm only interested in having temp and humidity values, because probably the sensor will be permanently energized, so don't mind about power save modes.

Thanks for any help.
Fernando

SHT3X driver is not enabled in the firmware by default.
If you have a git account, you can download a version with this driver in the artifacts of
PR #1601.

>>21517270
Good morning
Thanks max4elektroda, you nailed it.

Hi,
Today I was trying to connect other Tuya sensor to my Home Assistant setup, and I saw that there was an upgrade. As soon as the upgrade started to roll, the sensor, I have the one above, stopped publishing temperature and humidity.
On the log was the same that I posted on 5#, I tried to roll back to version "OpenBK7231N_1.18.118.rbl", no luck.
Can someone get me the ota file with sht3x driver, or explain what am I doing wrong?

Thanks.

I think that Releases section has _sensors build version of OpenBeken available for download. https://github.com/openshwprojects/OpenBK7231T_App

>>21614257
Thanks p.kaczmarek2, by the way, why so many versions? Couldn't they all fit in one single release?

Hi,

I've the same TH01 as posted in the first message but it doesn't show temperature or humidity.
Running on Built on Oct 26 2025 04:10:36, version 1.18.206.
In the log nothing is mentioned about missing driver. I've added in autoexec.bat: startDriver SHT3X



But only one driver is loaded



I took a good look at the sensor and it's an 8-pin GTH30 (https://www.lcsc.com/datasheet/C3010791.pdf) instead of a SHT30, but don't know if I need another driver. All the pins are connected as earlier mentioned (GHT30 pin1 SDA to PWM2/P8 pin 24, and GHT30 pin4 SCL to PWM1/P7 pin 23)





I've tried it on two others with the same result. I'm curious if one of you faced the same issue and if you have a solution.
Thanks

SHT30 driver is available in the Sensors release of OpenBeken

https://github.com/divadiow/OpenBK7231T_App/blob/main/src/obk_config.h#L340



Not heard of GHT30 before.

You could swap SHT3X assignment now for SoftSDA and SoftSCL, run startdriver i2c then try scani2c soft command

do you get an i2c address back like



it looks like SHT3X driver expects 0x44
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/src/driver/drv_sht3x.c#L16

Yes, brilliant. It cost me days, but this is the solution! Thanks.

startdriver i2c gave me the feedback that it was loaded; startDriver SHT3X gave me this:



So I've flashed the release which you mentioned and I've finally the sensor output.



Thanks again.

interesting. Good to know this GHT30 is compatible.