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Aqia Smart Plug F3202-US Teardown and Home Assistant Integration Guide

spamdump43230 1836 2

TL;DR

  • Aqia F3202-US Wi‑Fi smart outlet teardown shows a Tuya-based socket controlled by a WB2S module and adapted for Home Assistant via MQTT.
  • The conversion requires desoldering the H3/H4 power posts, removing the WB2S board, and flashing custom firmware through UART on VBAT, GND, 1RX, 1TX, and CEN.
  • Pin mapping uses Pin 11 for LED, Pin 24 for Rel, and Pin 26 for Btn; the outlet runs as channel 1.
  • Four units were converted successfully, and the sockets are rated for 15A, though desoldering overheated and deformed the case.
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📢 Listen (AI):
  • This is a teardown for an Aqia Model F3202-US Wifi smart outlet. This outlet is controlled via a WB2S module.

    Item description page from MicroCenter

    This was my first reformatting of any sort of smart appliance. I made this work with Home Assistant via the MQTT protocol. I got four of them on sale for $5 each, and was able to convert them all.

    Here is the back of the unit.
    Rear view of Aqia Model F3202-US Wi-Fi smart plug.

    Opened a bit so you can see where to pry the case.
    Partly open Aqia Model F3202-US Wi-Fi smart plug.

    The top side of the control board (A point of pride for me - the yellow C2 was ALREADY melted when I opened it!) This is after desoldering the H3 and H4 contacts.
    Desoldering those was pretty much the hardest part of this entire process. There is a very large mound of solder on them and you either have to use a LOT of desoldering braid, or a vacuum de-soldering tool to work on them. I did four of these sockets and ended up heat-deforming the case on all four.
    Circuit board of a smart Wi-Fi outlet with electronic components

    You can see the desoldered posts here. Notice the melted plastic. Also notice the rings around the posts that are still attached.
    View of the internal part of the casing and components of the smart Wi-Fi socket.

    Once you have the controller board separated from the housing, you can access the back of the control board and see where the WB2S is attached.
    Controller board of Aqia F3202-US Wi-Fi smart socket with visible traces and pins.
    Image of a circuit board with visible connectors labeled GND, 3V3, RX, TX.

    At first, I tried to talk to the WB2S directly, but the circuitry on the controller board was messing me up:
    Circuit board with soldered wires of different colors.

    So I followed the advice given here and removed the WB2S board and worked directly with it.
    That removal process is demonstrated very well in this youtube video at around 1 minute and 40 seconds:



    As I sit looking at this now, I realize I used the WORST possible colored wires to make a post about this board.
    Please notice that in this picture, there are leads attached to VBAT, GND, 1RX, and 1TX on this side of the WB2S.
    There are actually TWO leads attached to GND here, one which goes to the UART programmer and the other to the push button shown below.
    Close-up of a WB2S module with attached wires.


    On the OTHER side of the WB2S, there is a lead attached to CEN. This also goes to the button shown below.
    WB2S module with soldered wires on a blue mat.

    This is the best picture I could get that shows the button. This is a momentary, Normally Open button switch. This allows for an EASY WAY
    to activate the programming mode on the WB2S chip when are using the flashing tool. I tried several times to do it with just touching the wires together, or touching the chip at just the right time, but this actually makes it simple and much less of a hassle.
    PCB board with connected multicolored wires.

    I used a cheap UART programmer with the output set to 3.3V to hook up to my Windows PC.
    UART Programmer listing on Amazon.com
    UART programmer module with micro USB port and pins on the board.

    I used those DuPont breadboard wires to make connecting it easy.
    VOUT -> VBAT, GND -> GND, TXD -> 1RX, RXD -> 1TX (cross over the TX/RX pins)

    I would add the steps for running the software, but I tried to follow two of the older posts, and the software had changed enough to make it harder instead of easier.
    The basic steps are:
      1 - Download the right firmware file
      2 - Connect the UART programmer to Windows (plug it into a USB port)
      3 - Start the flashing software
      4 - Backup the current firmware on the WB2S to a file on your PC (there's a button on the screen)
      5 - Write the new firmware to the WB2S (there's a button on the screen)
      6 - Write the configuration file to map the pins to the functions (there's a button on the screen)

    The important part for this switch or any device is the "pins" and what they do. This software will send signals to pins based on commands.
    So if your first relay is on pin 24 of channel 1, you need to configure this WB2S to know that when it gets the "turn relay 1 on" command, it knows to set pin 24 to high.

    For this switch there are four controls:
    "Btn", which is the "is this switch on?" light inside the little button on the front
    "LED", which is the blinky light when it's connecting to the network
    "Rel", which is the Relay for the power

    Two things:
    This switch only has one outlet, so everything is "channel" 1. If you had more outlets in the device, they would each get a new channel.
    This switch treats "LED" like most other devices on this list treat the "WifiLED." Not sure why, but trial and error showed it to be the case. So to see the button light up with you turn on the switch, you need to map the "Btn" command.

    The mappings are
    Pin 11 - LED
    Pin 24 - Rel
    Pin 26 - Btn

    The JSON file that makes this go more quickly is included here. You'll use the firmware writer program to flash it to the WB2S

    Code: JSON
    Log in, to see the code


    (copying without the syntax tag so you don't need to log in to see it)
    {
    "reset_t":"3",
    "rl1_lv":"1",
    "netled_lv":"1",
    "bt_type":"0",
    "bt1_pin":"26",
    "ch_flag1":"1",
    "inch_dp":"44",
    "rand_dpid":"43",
    "net_trig":"2",
    "module":"WB2S",
    "ch_cddpid1":"9",
    "led_)Bgw_wsmdp":"40",
    "jv":"1.1.5",
    "init_conf":"38",
    "lock_dp":"41",
    "cyc_dpid":"42",
    "ch_num":"1",
    "netled_pin":"11",
    "total_stat":"2",
    "reuse_led_m":"1",
    "rl_type":"0",
    "rl1_pin":"24",
    "ch_dpid1":"1",
    "bt1_lv":"0",
    "crc":"100"
    }

    The requirements for posting a teardown say to include the JSON file from the Web Application main page, so I'm including that here as well. I think you'll see it's the template with only the pins changed

    Code: JSON
    Log in, to see the code


    (copying without the syntax tag so you don't need to log in to see it)
    {
    "vendor": "Tuya",
    "bDetailed": "0",
    "name": "Full Device Name Here",
    "model": "enter short model name here",
    "chip": "BK7231T",
    "board": "TODO",
    "flags": "1024",
    "keywords": [
    "TODO",
    "TODO",
    "TODO"
    ],
    "pins": {
    "11": "LED;1",
    "24": "Rel;1",
    "26": "Btn;1"
    },
    "command": "",
    "image": "https://obrazki.elektroda.pl/YOUR_IMAGE.jpg",
    "wiki": "https://www.elektroda.com/rtvforum/topic_YOUR_TOPIC.html"
    }

    I'm sorry I can NOT remember how I originally got the pins configured. I think I used the web page that becomes available after the socket connects to your network. From there, you can change local settings. Using the original firmware backup, I was able to poke around and see which pins has something defined. Then by trying different values on those pins in the configuration, I could make it work. Then I put those configurations into an OBK template JSON file and loaded that using the firmware writer. For subsequent sockets, I could just load that same JSON file and it worked.

    Hopefully, this will help someone else get these up and running. They are nice because they handle a full 15A, whereas most of the wifi sockets are limited to 10A.

    If you are a tinkerer, feel free to contact me at spamdump43230(_at_)gmail.com to let me know if I left anything out or to make corrections.

    Cool? Ranking DIY
    About Author
    spamdump43230
    Level 1  
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    spamdump43230 wrote 1 posts with rating 5, helped 1 times. Been with us since 2024 year.
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  • #2 21375892
    p.kaczmarek2
    Moderator Smart Home
    Posts: 14444
    Help: 650
    Rate: 12414
    Good job, regarding the desoldering those two huge pins, I would try to mix the Pb-free solder with some old classic leaded solder to lower the melting point of the whole mix. Then braid/solder wick, as you said.

    Alternatively, once you knew where CB2S pads are, you could just cut a hole in the casing there, but it could me in many ways worse than desoldering... depending on your equipment and skills. I'm just saying there is also such option.
    Helpful post? Buy me a coffee.
📢 Listen (AI):

FAQ

TL;DR: For Home Assistant tinkerers, this guide turns a 15A Aqia F3202-US plug into a local MQTT device. The author converted 4 plugs at $5 each and said the button method "actually makes it simple" for WB2S flashing. It also gives the exact OBK pins: 11, 24, and 26. [#21371464]

Why it matters: It shows a repeatable path from a cheap retail smart plug to local Home Assistant control, while documenting the main teardown risk: hard-to-desolder high-mass pins.

Option What it changes Advantage Main drawback
Add leaded solder + braid Lowers the solder mix melting point Cheaper and more controlled Still labor-intensive on large pins
Vacuum desoldering tool Removes the large solder mound faster Best for H3/H4 posts Requires extra equipment
Cut access hole near module pads Avoids full desoldering path May skip board removal Can damage the case and looks worse

Key insight: The fastest reliable result came from removing the WB2S module and flashing it off-board, then loading a JSON template with Pin 11 = LED, Pin 24 = relay, and Pin 26 = button LED/input. [#21371464]

Quick Facts

  • The plug is sold as a 15A Wi‑Fi outlet, which the author highlights as higher than the 10A limit common on many other Wi‑Fi plugs. [#21371464]
  • The author bought 4 units for $5 each and successfully converted all four to Home Assistant over MQTT. [#21371464]
  • The UART setup used 3.3V output and four core connections: VBAT, GND, 1RX, and 1TX, with TX/RX crossed. [#21371464]
  • Confirmed OpenBeken mappings are Pin 11 = LED, Pin 24 = Rel, and Pin 26 = Btn, all on channel 1 because the device has one outlet. [#21371464]
  • A later thread reply notes a webapp update tied to commit ac72759981b9179279fc0674d82e4772a37f6736, indicating the device template work was tracked after the teardown. [#21376348]

How do I flash an Aqia Smart Plug F3202-US with a WB2S module so it works with Home Assistant over MQTT?

You flash it by removing the WB2S, connecting a 3.3V UART adapter, writing new firmware, and then loading the correct JSON pin map. 1. Open the case and separate the control board. 2. Remove the WB2S and wire VBAT, GND, 1RX, and 1TX to a Windows PC UART programmer. 3. Back up the original firmware, flash the new firmware, and load the JSON with Pin 11, 24, and 26 assignments. The author used this process on 4 plugs and then controlled them in Home Assistant over MQTT. [#21371464]

What are the correct pin mappings for the Aqia F3202-US smart plug in OpenBeken or OBK?

The correct mappings are Pin 11 for LED, Pin 24 for Rel, and Pin 26 for Btn. The device has one outlet, so every function stays on channel 1. The author also notes that the visible button light follows the Btn mapping here, not the more typical WifiLED-style behavior used by many other devices. [#21371464]

Why is it difficult to desolder the H3 and H4 posts on the Aqia F3202-US control board, and what tools work best?

It is difficult because H3 and H4 hold a very large mound of solder that takes much more heat and removal effort than the small WB2S pads. The author calls those two contacts the hardest part of the whole process. A lot of desoldering braid can work, but a vacuum desoldering tool is the more effective option on these large posts. [#21371464]

What's the safest way to open the Aqia F3202-US case without melting or deforming the plastic housing?

The safest method in this thread is to pry the case open first, then minimize heat time before attacking the large solder posts. The author shows where to pry, but still heat-deformed all 4 housings while desoldering H3 and H4. If you already know where the module pads sit, one reply suggests cutting an access hole instead of full desoldering, but only as an alternative with its own risks. [#21371464]

How should I wire a 3.3V UART programmer to a WB2S module for flashing, including VBAT, GND, 1RX, and 1TX?

Wire the 3.3V UART adapter as VOUT to VBAT, GND to GND, TXD to 1RX, and RXD to 1TX. You must cross TX and RX. The author used a cheap UART programmer set to 3.3V, DuPont wires, and a Windows PC for the flashing setup. [#21371464]

What is a WB2S module, and how does it relate to the BK7231T chip used in Tuya smart plugs?

WB2S is a Wi‑Fi module that mounts on the smart plug control board, exposes VBAT, GND, UART, and CEN connections, and carries the logic the author reflashed for local control. In the included template JSON, the device vendor is Tuya, the module is listed as WB2S, and the chip field is BK7231T, showing the module-to-chip pairing used on this plug. [#21371464]

What is MQTT in the context of Home Assistant smart plug integration, and why would someone use it instead of the stock cloud app?

MQTT is the protocol the author used to make the Aqia plug work with Home Assistant after reflashing. In this thread, the practical reason is clear: it let the author convert 4 sale-priced plugs into Home Assistant devices after replacing the original firmware path. That gives a local integration workflow instead of staying with the plug's original app-based setup. [#21371464]

Why does the Aqia F3202-US button light require the 'Btn' mapping instead of the usual WifiLED-style mapping?

This plug drives the button light from the Btn function, not from the network LED function. The author found that by trial and error. They state that this device treats LED differently from many other templates, so you must map Btn to see the front button light when the switch turns on. [#21371464]

Which works better for removing lead-free solder on large smart plug pins: adding leaded solder and braid, or using a vacuum desoldering tool?

Both can work, but the stronger method here is a vacuum desoldering tool. The original teardown says the H3 and H4 posts need either a lot of braid or vacuum desoldering. A follow-up reply adds that mixing lead-free solder with classic leaded solder lowers the melting point first, making braid or wick more effective on the large pins. [#21375892]

How do I put a WB2S module into programming mode using a momentary normally open button connected to CEN and GND?

Use a momentary normally open pushbutton that shorts CEN to GND when pressed. The author soldered one lead to CEN on one side of the WB2S and another ground lead to GND on the other side. They say this button method made programming mode easy and much less of a hassle than touching loose wires at the right moment. [#21371464]

What steps should I follow in the firmware flashing software to back up the original Aqia plug firmware, write new firmware, and load the JSON configuration?

Follow the software flow in this order: back up first, flash second, configure last. The author lists six steps: download the right firmware file, connect the UART programmer, start the software, back up the current WB2S firmware, write the new firmware, and then write the JSON configuration file. That backup matters because the author later used the original firmware image to inspect which pins had functions defined. [#21371464]

How can I identify the relay, network LED, and button LED pins on a Tuya-based smart plug when I don't have a published template?

Start by checking the original firmware backup for defined pins, then test candidate pins one by one in the local configuration page. That is how the author reconstructed the working map. On this Aqia plug, that process led to Pin 24 for the relay, Pin 11 for the network LED, and Pin 26 for the button function. [#21371464]

What does the OpenBeken template JSON file do, and which fields matter most for configuring a single-outlet Aqia F3202-US device?

The OpenBeken template JSON file maps physical pins to logical functions so the flashed firmware knows what to switch or light. For this single-outlet Aqia plug, the important fields are the module or chip identity and the pins object. In the included template, the critical assignments are "11": "LED;1", "24": "Rel;1", and "26": "Btn;1", all tied to one channel. [#21371464]

What problems can happen if I try to flash the WB2S while it is still soldered to the Aqia smart plug control board?

The board circuitry can interfere with communication and make direct flashing unreliable. The author first tried talking to the WB2S in-circuit and says the control-board circuitry was "messing me up." They solved that by removing the WB2S and working directly with the module, which is the clearest failure case documented in the thread. [#21371464]

Why might someone choose the Aqia F3202-US 15A smart plug over more common 10A Wi-Fi plugs for Home Assistant projects?

You would choose it when you want a higher current rating than the 10A limit common on many Wi‑Fi plugs. The author specifically calls out the Aqia unit's full 15A handling as a selling point after the reflash. They also proved the economics were attractive by converting 4 units bought on sale for $5 each. [#21371464]
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