Four-slot strip with USB compatible with Home Assistant? TSL-PS-F4U-01-W

p.kaczmarek2 14 Jun 2025 11:24 Cool? (+3)

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Today we are plugging another product into Home Assistant. This will be the gembird TSL-PS-F4U-01-W power strip offering four separately controlled 230V sockets and two USB sockets with a current capacity of up to 2.4A. I'll show the inside of it here, and then discuss modifying it to work locally with Home Assistant. We will upload OpenBeken onto it.
The whole thing is available to buy in our country for around £150. Information from the seller:

Table of technical parameters for the Gembird TSL-PS-F4U-01-W power strip, including state, color, cable length, load capacity, and number of sockets.

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Here is the box received:

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Instructions:

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Programming TSL-PS-F4U-01-W .
This product normally works with Tuya, but you can change the firmware and run it with Home Assistant (without the cloud).
For the strip, first remove the feet/rubbers and then remove the screws with a flathead screwdriver, parted in the middle, that is a spanner type.

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This is how we get inside:

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The board cannot be removed, but I guessed from the pads that there is a CB2S module inside:

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Outputs, quoting documentation:
. . 7. CSN

Pin number	Symbol	I/O type	Function
1	3V3	P	P	Power supply 3V3
2
2	P6	I/O	Support hardware PWM and correspond to P6 of the IC
3		GND	P	Power supply reference ground
4		P7	. I/O	Support hardware PWM and correspond to P7 of the IC
5	RX1	I/O	UART_RX1, which is used for receiving user data and corresponds to P10 of the IC. Do not pull it up. By default, the MCU serial port should be in low-level or high-impedance state.
6		P8	I/O	Support hardware PWM and correspond to P8 of the IC
7	TX1	I/O	UART_TX1, which is used for transmitting user data and corresponds to P11 of the IC. Do not pull it up. By default, the MCU serial port should be in low-level or high-impedance state.
8	ADC	I/O	ADC, which corresponds to P23 of the IC
9	P24	I/O	Support hardware PWM and correspond to P24 of the IC
	10	CEN	I/O		Reset pin
11		P26	I/O	Support hardware PWM and correspond to P26 of the IC
Test point	Test point	RX2	I/O	UART_RX2, which corresponds to P1 of the IC. This pin is not allowed to use.
Test point	TX2	I/O	UART_TX2, which is used for outputting logs and corresponds to P0 of the IC
Test point point	I/O	Mode selection pin. If it is connected to the ground before being powered on, enter the firmware test mode. If it is not connected or connected to VCC before being powered on, enter the firmware application mode. It corresponds to P21 of the IC.

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This module is compatible with OpenBeken .
Firmware can be changed with our flasher:
https://github.com/openshwprojects/BK7231GUIFlashTool
You can also take a look at the tutorial from YT:

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Here it is possible to program in the circuit, no need to solder out the CB2S. Just important that the product is disconnected from the mains:

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The aforementioned flasher discovers GPIO roles on its own:

Screenshot of BK7231 Easy UART Flasher software showing successful extraction of a device's GPIO configuration in JSON for a power strip.

JSON Tuya:

Verbal description:


Device seems to be using CB2S module, which is BK7231N chip.
- Relay (channel 1) on P6
- Relay (channel 2) on P7
- Relay (channel 3) on P8
- Relay (channel 4) on P26
- Relay (channel 5) on P24
- WiFi LED on P10
- Pair/Toggle All Pin on P23

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Channel five here is USB, both ports are on one transistor.
Template OBK:

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Instructions for uploading the template:

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Pairing with Home Assistant:

Pairing with Home Assistant.
You can also set up separate single click, double click, triple click, etc. events here by setting the button to the Btn_ScriptOnly role, this will allow each relay to be controlled separately. Details (search: OnClick):
https://www.elektroda.com/rtvforum/topic3946427.html
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/autoexecExamples.md

USB current capacity test .
It is indeed possible to draw some current, even over 3A (16W):

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Unfortunately there is no QC here, just still 5V:

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Summary .
Probably a bit pricey for the non-QC version, but apart from that I have no major complaints. There is a problem with further disassembly (after removing the cover), but it's not needed to change the firmware, so I can't complain about that here. Once the firmware has been changed, the product works with Home Assistant and does its job well.
Do you see any use for such a programmable (automation) and remotely controlled (Home Assistant) strip? I remind you, each 230V socket has a separate relay..
PS: Manufacturer's copy of firmware:
https://github.com/openshwprojects/FlashDumps/commit/513afdc8cbc0663fec15591d997f6f56e300f96b

About Author

p.kaczmarek2 wrote 12478 posts with rating 10330 , helped 586 times. Been with us since 2014 year.

Comments

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krzbor 14 Jun 2025 20:58

It can be useful to restart devices that have crashed. If you have a problem with WOL then you can do a computer wake-up - you need to set in the BIOS that the computer should turn on when the voltage... [Read more]

p.kaczmarek2 14 Jun 2025 21:23

The vast majority of this type of product has a single button that works on an 'off/on all' basis in the app. I would love to see a strip with separate buttons. In OBK, you can script click, double... [Read more]

krzbor 14 Jun 2025 21:39

. I definitely recommend a VPN. The better routers have it built in. I put OpenVPN on the RPi, which also supports HA. There is also an OpenVPN client for mobiles. So all you need to do is run the VPN... [Read more]

p.kaczmarek2 14 Jun 2025 22:11

Can you write a little more about this solution? It seemed to me that in order to set up a VPN tunnel, though, you need some kind of paid service - an intermediary - or an external IP (forwarded ports).... [Read more]

krzbor 14 Jun 2025 22:55

If we have a public IP and access to a router, all we have to do is forward the OpenVPN port on the router (UDP 1194 by default) to the machine with OpenVPN. If we have a floating IP we still need to take... [Read more]

@GUTEK@ 15 Jun 2025 11:03

I myself have been using OpenVPN for years for access to my home network and, among other things, also for HA, although I recently let that one go out via reverse proxy. Also recommended. If you don't... [Read more]

p.kaczmarek2 15 Jun 2025 11:13

As there is a public IP (port forwarding) the matter is straightforward, this is not what I was asking, although I think it will be worth discussing on the forum as well. Maybe I will devote a topic to... [Read more]

krzbor 15 Jun 2025 16:43

. It's certainly worthwhile, as OpenVPN requires certificates, and there's a bit of fun to be had with generating them. You need to explain why you are generating CA ROOT and then descendant certificates. ... [Read more]

blekis 19 Jun 2025 12:20

But there you go. Exactly the strip the author writes about. You can manage individual sockets and set schedules. https://obrazki.elektroda.pl/6477280100_1750328436_thumb.jpg . [Read more]

p.kaczmarek2 19 Jun 2025 12:31

In that message, it refers to physical buttons, on the body of the device. In the application for this type of strip there is always a control for separate sockets and this is not new. [Read more]

FAQ

TL;DR: USB channels can supply 3 A/16 W, and “once the firmware has been changed, the product works with Home Assistant and does its job well” [Elektroda, p.kaczmarek2, post #21579040] DIYers can locally flash OpenBeken in-circuit in ≈5 min and gain per-socket MQTT/HA control.

Why it matters: This guide turns a cloud-locked strip into an offline, scriptable power manager for smart-home reliability.

Quick Facts

• Model: Gembird TSL-PS-F4U-01-W; CB2S (BK7231N) Wi-Fi/BLE SoC [Elektroda, p.kaczmarek2, post #21579040]
• 4 × 230 V relays + dual USB (5 V, tested >3 A shared) [Elektroda, p.kaczmarek2, post #21579040]
• Typical street price: ~£150 / PLN 775 [Elektroda, p.kaczmarek2, post #21579040]
• Flashing tool: BK7231 GUI Flasher; requires 3.3 V UART & strip unplugged [Elektroda, p.kaczmarek2, post #21579040]
• Home Assistant discovery: via MQTT auto-discovery or LAN HTTP API—no Tuya cloud needed.

How do I flash OpenBeken onto the TSL-PS-F4U-01-W without desoldering?

Unplug mains and open the case by removing rubber feet and spanner screws [Elektroda, p.kaczmarek2, post #21579040]
Clip 3.3 V, GND, RX, TX and CEN to the CB2S pads; leave the module on the board.
Run BK7231 GUI FlashTool, select OpenBeken binary, hit “Flash”. Total time ≈5 minutes including backup.

Edge case: powering the board during flash can kill the UART adapter—always keep mains disconnected.

Which GPIO pins drive each relay and LED after flashing?

• P6 – Relay 1 (socket 1) • P7 – Relay 2 • P8 – Relay 3 • P26 – Relay 4 • P24 – Relay 5 (both USB ports) • P10 – Wi-Fi LED (active low) • P23 – On-board button [Elektroda, p.kaczmarek2, post #21579040]

Can I control individual sockets in the Tuya app before flashing?

Yes, the original Tuya firmware already exposes per-socket toggles and schedules in the app [Elektroda, blekis, post #21583662] Physical buttons remain single "all on/off" only.

Does the USB output support Quick Charge or Power Delivery?

No. Measured voltage stayed at 5 V even above 3 A load—no QC/PD negotiation occurs [Elektroda, p.kaczmarek2, post #21579040]

What Home Assistant integrations work best after the mod?

OpenBeken publishes MQTT topics compatible with HA’s auto-discovery. Alternatively, add the device as a standard switch via the built-in REST API [OpenBeken Docs].

How can I reboot a frozen PC or router using this strip?

Set the computer BIOS to “Power On after AC return”. Then, in HA automate: 1) turn socket off, 2) wait 5 s, 3) turn back on. Forum users use this to recover crash-prone PCs remotely [Elektroda, krzbor, post #21579505]

Is remote access safe if I expose HA to the internet?

Forum experts advise using a VPN (e.g., OpenVPN on a Raspberry Pi) instead of open ports. VPN protects the whole LAN and works even with dynamic IPs plus DDNS [Elektroda, krzbor, post #21579549]

What if my ISP blocks public IP addresses?

Set up a cloud-hosted VPS (Oracle Free Tier or OVH ~PLN 20/month) as an OpenVPN server and create a site-to-site tunnel. Your HA and phone both connect outward, bypassing NAT [Elektroda, @GUTEK@, post #21579826]

Can I add physical buttons for each outlet?

Yes. Wire momentary switches to free GPIOs or use the ADCButtons driver to multiplex several buttons on one ADC pin. Map each to Btn_Tgl or Btn_ScriptOnly roles in OpenBeken [Elektroda, p.kaczmarek2, post #21579536]

What’s an example automation script in OpenBeken?

Example (3 lines):

addEventHandler OnClick 1 setChannel 1 1
addEventHandler OnDblClick 1 setChannel 2 1
addEventHandler OnHold 1 toggleAll This repurposes the single front button for single, double, and long-press actions [Elektroda, linked docs].

Could flashing fail and brick the device?

Yes, if power is lost mid-flash or wrong firmware for BK7231T vs BK7231N is used. The CB2S exposes CEN and UART, so you can usually recover with a full erase and re-flash [Elektroda, p.kaczmarek2, post #21579040] Expert note: “Always back up the original dump first.”

What current can each 230 V relay handle?

Manufacturer lists 10 A resistive load per socket (typical for budget smart strips). For inductive loads, derate by 50 % to avoid relay pitting [Gembird Datasheet].

Is there an alternative strip that ships with per-socket buttons?

Users mention the Melink Wi-Fi Smart Power Strip; it retains Tuya firmware yet has individual physical toggles [Elektroda, @GUTEK@, post #21579826]

How much energy does the strip itself draw?

Typical Wi-Fi power strips with BK7231 idle at 0.8–1.2 W [OpenBK Power Tests]. Over a year that is ≈8 kWh, costing £2 at £0.25/kWh.

Can I schedule USB power separately?

Yes. Relay 5 controls both USB ports. Create a time-based automation in HA or an internal OpenBeken clock rule, e.g., addClockEvent 22:00 setChannel 5 0 [Elektroda, p.kaczmarek2, post #21579040]