Universal driver for I2C temperature/humidity sensors (AHT2x/CHT83xx/SHT3x/SHT4x) by MaxineMuster · Pull Request #2049 · openshwprojects/OpenBK7231T_App

MaxineMuster · 2026-03-26T17:52:09Z

To simplify temperature sensor usage, here's a combined AHT2x/CHT83xx/SHT3x/SHT4x driver.

Just provide with SDA and SCL pin and driver will try the default addresses and readings to auto-detect the sensors.

Here's my test board with BK7238 board with AHT10 - SHT31 - SHT40 - CHT3805 sensor

We have
AHT10 SDA=23 SCL=28
SHT31 SDA=24 SCL=16
SHT40 SDA=14 SCL=26
CHT3805 SDA=20 SCL=21

So I "simply" start

backlog startdriver XHTXX -SCL 26 -SDA 14; XHTXX_AddSensor -SCL 28 -SDA 23; XHTXX_AddSensor -SCL 16 -SDA 24; XHTXX_AddSensor -SCL 21 -SDA 20
Log:

Info:MAIN:Time 15, idle 404818/s, free 117192, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 16, idle 397308/s, free 117176, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 17, idle 393238/s, free 117176, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Starting XHTXX.
Info:SENSOR:XHTXX: auto-detect SDA=14 SCL=26...
Info:SENSOR:XHTXX: found SHT4x at 0x44
Info:SENSOR:XHTXX SHT4x (SDA=14): T=19.1°C H=46.6%
Info:SENSOR:XHTXX SHT4x ok (SDA=14)
Info:MAIN:Started XHTXX.
Info:SENSOR:XHTXX: auto-detect SDA=23 SCL=28...
Info:SENSOR:SHT_Probe: CRC (SDA=23)
Info:SENSOR:SHT_Probe: CRC (SDA=23)
Info:SENSOR:SHT_Probe: CRC (SDA=23)
Info:SENSOR:XHTXX: found AHT2x at 0x38
Info:SENSOR:XHTXX AHT2x ok (SDA=23)
Info:SENSOR:XHTXX: auto-detect SDA=24 SCL=16...
Info:SENSOR:SHT_Probe: CRC (SDA=24)
Info:SENSOR:XHTXX: found SHT3x at 0x44
Info:SENSOR:XHTXX SHT3x (SDA=24): T=19.1°C H=51.9%
Info:SENSOR:XHTXX SHT3x ok (SDA=24)
Info:SENSOR:XHTXX: auto-detect SDA=20 SCL=21...
Info:SENSOR:SHT_Probe: CRC (SDA=20)
Info:SENSOR:SHT_Probe: CRC (SDA=20)
Info:SENSOR:SHT_Probe: CRC (SDA=20)
Info:MAIN:Time 18, idle 433967/s, free 103912, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 3/24 
Info:SENSOR:XHTXX CHT83xx mfr=5959 dev=8305
Info:SENSOR:XHTXX: found CHT83xx at 0x40
Info:SENSOR:XHTXX CHT8305 init (SDA=20)
Info:CMD:[WebApp Cmd 'backlog startdriver XHTXX  -SCL 26 -SDA 14;  XHTXX_AddSensor -SCL 28 -SDA 23; XHTXX_AddSensor  -SCL 16 -SDA 24; XHTXX_AddSensor  -SCL 21 -SDA 20' Result] OK
Info:SENSOR:XHTXX SHT4x (SDA=14): T=19.1°C H=46.6%
Info:SENSOR:XHTXX AHT2x (SDA=23): T=18.7°C H=40.4%
Info:SENSOR:XHTXX SHT3x (SDA=24): T=19.1°C H=51.9%
Info:MAIN:Time 19, idle 418760/s, free 116536, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:SENSOR:XHTXX CHT83xx (SDA=20): T=19.1°C H=48.3%
Info:MAIN:Time 20, idle 752410/s, free 115952, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 3/24 
Info:MAIN:Time 21, idle 378804/s, free 116536, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 22, idle 384016/s, free 116536, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 23, idle 383107/s, free 116536, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 24, idle 400017/s, free 116536, MQTT 0(1), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MQTT:mqtt_host empty, not starting mqtt
Info:MAIN:Time 25, idle 377876/s, free 116536, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 26, idle 387136/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 27, idle 391169/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 28, idle 405546/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 29, idle 393475/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:SENSOR:XHTXX SHT4x (SDA=14): T=19.1°C H=46.7%
Info:SENSOR:XHTXX AHT2x (SDA=23): T=18.6°C H=40.5%
Info:SENSOR:XHTXX SHT3x (SDA=24): T=19.1°C H=52.0%
Info:MAIN:Time 30, idle 421402/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:SENSOR:XHTXX CHT83xx (SDA=20): T=19.1°C H=48.4%
Info:MAIN:Time 31, idle 352292/s, free 116984, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 32, idle 383450/s, free 108680, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 33, idle 397672/s, free 108680, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24 
Info:MAIN:Time 34, idle 387088/s, free 108680, MQTT 0(2), bWifi 1, secondsWithNoPing -1, socks 2/24

GUI:

Again (my observation) while temperatures are realistic, humidity values are more or less guesswork it seems ...

Size is about 5k - for sensor variants, size will reduce, if only xHTxx is selected, but the "replaced" drivers AHT2x/SHT3x/CHT38xx deselected:

Size +/- Filename -1452 OpenW800_XX.fls -1392 OpenBK7231T_XX_sensors.bin -1392 OpenBK7238_XX_battery.bin -1368 OpenBK7231N_XX_battery.bin -1120 OpenBK7231N_XX_sensors.bin -352 OpenBK7231N_UG_XX_irRemoteESP.bin -224 OpenBK7231N_UG_XX_battery.bin -192 OpenBK7231T_UG_XX_irRemoteESP.bin -128 OpenBK7231N_UG_XX_powerMetering.bin -96 OpenBK7231T_UG_XX_powerMetering.bin -64 OpenBK7231N_UG_XX_tuyaMCU.bin -32 OpenBK7231T_UG_XX_sensors.bin -16 OpenBK7231N_UG_XX_hlw8112.bin 0 OpenBK7231M_ALT_QIO_XX.bin 0 OpenBK7231M_ALT_QIO_XX_btproxy.bin 0 OpenBK7231M_QIO_XX.bin ...
256 OpenRTL87X0C_XX.bin 256 OpenRTL87X0C_XX_btproxy.bin 269 obkSimulator_XX.zip 2048 OpenBK7231N_UG_XX_berry.bin 2112 OpenBK7231T_UG_XX.bin 2192 OpenBK7231T_UG_XX_berry.bin 2400 OpenBK7231N_UG_XX.bin 2496 OpenRTL8720E_XX.bin 2512 OpenRTL8710A_XX.bin 2576 OpenRTL8710B_XX.bin 2608 OpenBK7231T_XX.bin 2616 OpenBK7231T_XX_berry.bin 2672 OpenESP32C2_XX_4M.factory.bin 2672 OpenESP32C2_XX_4M.img 2688 OpenESP32C2_XX_2M.factory.bin 2688 OpenESP32C2_XX_2M.img 2688 OpenESP32C3_XX_2M.factory.bin 2688 OpenESP32C3_XX_2M.img 2688 OpenESP32C3_XX_4M.factory.bin 2688 OpenESP32C3_XX_4M.img 2688 OpenESP32C5_XX_4M.factory.bin 2688 OpenESP32C5_XX_4M.img 2704 OpenESP32C61_XX_4M.factory.bin 2704 OpenESP32C61_XX_4M.img 2704 OpenESP32C6_XX_4M.factory.bin 2704 OpenESP32C6_XX_4M.img 2704 OpenESP32S2_XX_4M.factory.bin 2704 OpenESP32S2_XX_4M.img 2720 OpenESP32S3_XX_4M.factory.bin 2720 OpenESP32S3_XX_4M.img 2804 OpenBK7252N_XX.bin 2816 OpenESP32_XX_4M.factory.bin 2816 OpenESP32_XX_4M.img 2824 OpenBK7252_XX.bin 2832 OpenBK7231N_ALT_XX.bin 2856 OpenBK7231N_ALT_XX_btproxy.bin 2856 OpenBK7238_XX.bin 2860 OpenBK7238_XX_berry.bin 2864 OpenBK7231T_ALT_XX.bin 2876 OpenBK7231U_XX.bin 2880 OpenBK7231N_XX.bin 2880 OpenBK7238_XX_btproxy.bin 2912 OpenBK7231N_XX_berry.bin 4384 OpenRTL8721DA_XX.bin 4924 OpenECR6600_XX.bin 5008 OpenBL602_XX_berry.bin 5040 OpenBL602_XX.bin 5068 OpenRDA5981_XX.bin 5120 OpenXR806_XX.img 5136 OpenTR6260_XX.bin 5152 OpenRTL8710B_UG_XX.img 256 OpenRTL87X0C_XX.bin 256 OpenRTL87X0C_XX_btproxy.bin 269 obkSimulator_XX.zip 2048 OpenBK7231N_UG_XX_berry.bin 2112 OpenBK7231T_UG_XX.bin 2192 OpenBK7231T_UG_XX_berry.bin 2400 OpenBK7231N_UG_XX.bin 2496 OpenRTL8720E_XX.bin 2512 OpenRTL8710A_XX.bin 2576 OpenRTL8710B_XX.bin 2608 OpenBK7231T_XX.bin 2616 OpenBK7231T_XX_berry.bin 2672 OpenESP32C2_XX_4M.factory.bin 2672 OpenESP32C2_XX_4M.img 2688 OpenESP32C2_XX_2M.factory.bin 2688 OpenESP32C2_XX_2M.img 2688 OpenESP32C3_XX_2M.factory.bin 2688 OpenESP32C3_XX_2M.img 2688 OpenESP32C3_XX_4M.factory.bin 2688 OpenESP32C3_XX_4M.img 2688 OpenESP32C5_XX_4M.factory.bin 2688 OpenESP32C5_XX_4M.img 2704 OpenESP32C61_XX_4M.factory.bin 2704 OpenESP32C61_XX_4M.img 2704 OpenESP32C6_XX_4M.factory.bin 2704 OpenESP32C6_XX_4M.img 2704 OpenESP32S2_XX_4M.factory.bin 2704 OpenESP32S2_XX_4M.img 2720 OpenESP32S3_XX_4M.factory.bin 2720 OpenESP32S3_XX_4M.img 2804 OpenBK7252N_XX.bin 2816 OpenESP32_XX_4M.factory.bin 2816 OpenESP32_XX_4M.img 2824 OpenBK7252_XX.bin 2832 OpenBK7231N_ALT_XX.bin 2856 OpenBK7231N_ALT_XX_btproxy.bin 2856 OpenBK7238_XX.bin 2860 OpenBK7238_XX_berry.bin 2864 OpenBK7231T_ALT_XX.bin 2876 OpenBK7231U_XX.bin 2880 OpenBK7231N_XX.bin 2880 OpenBK7238_XX_btproxy.bin 2912 OpenBK7231N_XX_berry.bin 4384 OpenRTL8721DA_XX.bin 4924 OpenECR6600_XX.bin 5008 OpenBL602_XX_berry.bin 5040 OpenBL602_XX.bin 5068 OpenRDA5981_XX.bin 5120 OpenXR806_XX.img 5136 OpenTR6260_XX.bin 5152 OpenRTL8710B_UG_XX.img 1.18.279 xHTxx_55bdcae3020e
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Change obk_config.h to disable the drivers xHTxx is replacing

if any of the contained drivers (AHT2x, CHT83XX or SHT3X) was defined, use xhtxx instead

smaller output if Tokenizer index is out of range

…24: true)

SHT3x: try up to 3 times to set alarm registers if setting fails (NAK)

Use "SHT_xy" command names as in drv_sht3x.c for SHT3x only commands Change GetSensors to accept a sensor family so it can return first sensor of this family if sensor index is ommited

MaxineMuster and others added 17 commits March 21, 2026 19:46

First commit for a clean checkout

ecfab67

Try fix for tasmota selftes (src/selftest/selftest_tasmota.c)

9fb674b

Change obk_config.h to disable the drivers xHTxx is replacing

some optimization for SHT families (using "unified" functions)

d1dbf85

Fix (link instead of file)

00efb2c

Edit obk_config:

d05a47c

if any of the contained drivers (AHT2x, CHT83XX or SHT3X) was defined, use xhtxx instead

make show uesd pinns" not default but gete by ENABLE_USED_PIN

8866ef9

smaller output if Tokenizer index is out of range

Switch to node 24 to avoid warnings (FORCE_JAVASCRIPT_ACTIONS_TO_NODE…

c128342

…24: true)

Second try - set "FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true" in every job

7c5cc4b

Next try - switchin to new versions

cdc6df6

try fix

e84fc66

Fix AHT2x humidity calc

7dc905a

SHT3x: try up to 3 times to set alarm registers if setting fails (NAK)

Add delay arg to I2C_ReadReg - fix for CHT83xx measurements

a2eb9a5

Merge branch 'openshwprojects:main' into xHTxx

55bdcae

Add/fix documentation

2eb53c1

Use "SHT_xy" command names as in drv_sht3x.c for SHT3x only commands Change GetSensors to accept a sensor family so it can return first sensor of this family if sensor index is ommited

Merge remote-tracking branch 'upstream/main' into xHTxx

2924edd

try setting tokenizer to actual version

b0a9c11

Add driver to XRADIO platform

e0fbb47

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Universal driver for I2C temperature/humidity sensors (AHT2x/CHT83xx/SHT3x/SHT4x)#2049

Universal driver for I2C temperature/humidity sensors (AHT2x/CHT83xx/SHT3x/SHT4x)#2049
MaxineMuster wants to merge 17 commits intoopenshwprojects:mainfrom
MaxineMuster:xHTxx

MaxineMuster commented Mar 26, 2026

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MaxineMuster commented Mar 26, 2026

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