Hello,
Today I’m sharing a teardown and analysis of a Tuya-based DIN rail smart switch with power monitoring.
This device offers: 5 relay outputs, energy monitoring, Tuya Smart Life compatibility
📦 External overview
🔧 Opening the enclosure
To open it, use a triangle screwdriver (sic) or a small flathead screwdriver.
![[BK7238 / T1] Smart Power Strip RH-EU411-4UW with energy monitoring [BK7238 / T1] Smart Power Strip RH-EU411-4UW with energy monitoring](https://obrazki.elektroda.pl/2068340000_1771076241_thumb.jpg)
Inside we find the main board.
A small carrier circuit:
And a BL0942 energy metering IC chip:
The BL0942 is connected via UART to the T1-U-HL module for energy reporting.
The device uses a T1-U-HL module. Datasheet
This version integrates a BK7238.
Unlike this version which uses a BK7231N.
🔍 Firmware & pin extraction
Connect the FT232 to 3V3, RX, TX and GND from the T1-U-HL carrier and start BK7231 GUI flash tool.
Configuration extracted from Tuya firmware:
Relay mapping:
Channel Pin
Relay 1 P26
Relay 2 P9
Relay 3 P24
Relay 4 P21
Relay 5 P6
Other functions
Function Pin
Toggle / Pair button P22
WiFi LED P23
Energy monitoring is enabled and handled through the BL0942 via UART.
Current template:
Product link: https://fr.aliexpress.com/item/1005006854933102.html
Today I’m sharing a teardown and analysis of a Tuya-based DIN rail smart switch with power monitoring.
This device offers: 5 relay outputs, energy monitoring, Tuya Smart Life compatibility
📦 External overview
🔧 Opening the enclosure
To open it, use a triangle screwdriver (sic) or a small flathead screwdriver.
Inside we find the main board.
A small carrier circuit:
And a BL0942 energy metering IC chip:
The BL0942 is connected via UART to the T1-U-HL module for energy reporting.
The device uses a T1-U-HL module. Datasheet
This version integrates a BK7238.
Unlike this version which uses a BK7231N.
🔍 Firmware & pin extraction
Connect the FT232 to 3V3, RX, TX and GND from the T1-U-HL carrier and start BK7231 GUI flash tool.
Configuration extracted from Tuya firmware:
Au format JSON :
{
"rl1_lv":"1",
"bt_type":"0",
"rl3_pin":"24",
"rl3_lv":"1",
"net_trig":"4",
"rl4_pin":"21",
"jv":"1.0.1",
"netled1_lv":"1",
"netled_reuse":"0",
"total_bt_pin":"22",
"nety_led":"0",
"total_stat":"2",
"over_cur":"16700",
"rl5_lv":"1",
"reset_t":"5",
"netled1_pin":"23",
"chip_type":"3",
"rl2_lv":"1",
"lose_vol":"0",
"over_vol":"0",
"module":"T1-U-HL",
"ch_cddpid1":"9",
"rl2_pin":"9",
"ch_cddpid4":"12",
"ch_cddpid5":"13",
"ch_cddpid2":"10",
"ch_cddpid3":"11",
"rl5_pin":"6",
"total_bt_lv":"0",
"ch_dpid5":"5",
"ch_num":"5",
"ele_fun_en":"1",
"rl1_pin":"26",
"rl4_lv":"1",
"ch_dpid3":"3",
"ch_dpid4":"4",
"netn_led":"0",
"vol_def":"0",
"ch_dpid1":"1",
"ch_dpid2":"2",
"crc":"12",
"em_sys_env":"T1"
}
Device configuration, as extracted from Tuya:
- Relay (channel 3) on P24
- Relay (channel 4) on P21
- Pair/Toggle All Button on P22
- WiFi LED on P23
- Relay (channel 2) on P9
- Relay (channel 5) on P6
- Relay (channel 1) on P26
Device seems to be using T1-U-HL module, which is using BK7238.
Device internal platform - T1, equals BK7238.
And the Tuya section starts at 2052096 (0x1F5000), which is a default T1/XR806 and some T34/BK7231N offset.
Relay mapping:
Channel Pin
Relay 1 P26
Relay 2 P9
Relay 3 P24
Relay 4 P21
Relay 5 P6
Other functions
Function Pin
Toggle / Pair button P22
WiFi LED P23
Energy monitoring is enabled and handled through the BL0942 via UART.
Current template:
{
"vendor": "Tuya",
"bDetailed": "1",
"name": "Smart Power Strip RH-EU411-4UW",
"model": "T1-U-HL 5CH DIN",
"chip": "BK7238",
"board": "T1-U-HL",
"flags": "1024",
"keywords": [
"Tuya",
"BK7238",
"DIN rail",
"energy monitoring",
"BL0942",
"relay module",
"OpenBeken"
],
"pins": {
"6": "Rel;5",
"9": "Rel;2",
"21": "Rel;4",
"22": "Btn_Tgl_All;0",
"23": "WifiLED_n;0",
"24": "Rel;3",
"26": "Rel;1"
},
"command": "startDriver BL0942",
"image": "https://obrazki.elektroda.pl/5119999700_1771076454.jpg",
"wiki": "https://www.elektroda.com/rtvforum/topic_YOUR_TOPIC.html"
}
Product link: https://fr.aliexpress.com/item/1005006854933102.html