BK7231 RF receiver driver tutorial - how to use SYN590R or similar to control multiple devices

p.kaczmarek2 15 Dec 2025 20:10 5 246 Cool? (+4)

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How to flash and configure RF remote receiver with open source firmware? How to use it to control relays and external devices, with and without Home Assistant? How to add custom remotes? Here's a short guide to RC (Radio Control) driver in OpenBeken, all basics covered. With this tutorial you'll be able to transform your simple RF relays controller into all-in-one RF control hub for many other Wi-Fi appliances, such as smart bulbs, LED strip controllers, external relay modules and much more.

Device used for presentation
The driver presented here can work with many devices and receivers, for presentation we used a popular Tuya 4-channel 220V AC Wi-Fi Remote Control Relay Switch Module 433 MHz RF from Aliexpress:

Wi-Fi relay module with 4 220V AC channels and labeled control components

This board features CB3S (BK7231) Wi-Fi module, which can be flashed with OpenBeken.

CB3S module on relay board with a red debugging wire connected

The device comes with a single remote, more remotes can be bought separately:

RF remote with 8 numbered buttons and antenna, text reads DIGITAL REMOTE CONTROLLER

Back of RF remote with battery cover removed and 23A 12V battery visible

This device features SYN590R (590R), which is connected directly to one of Wi-Fi module pads. It's not connected via external MCU, like on some devices, so in order to utilize it, Wi-Fi chip firmware must have a special driver for it. Luckily, there is such a driver in OBK!

Close-up of PCB with SYN590R RF module and 13.52127 MHz crystal oscillator

For the flashing part, see our BK7231 flasher page. Our flasher, which is a recommended solution for Beken and other OBK-supported chips, can also detect device configuration:

Screenshot of BK7231 Easy UART Flasher showing RF pin P20 configuration

Import the template and proceed to RF setup:

Basic guide for OBK RC driver
So, in order to run RC (Radio Control) driver in OBK, you need to set the RCRecv pin (check PCB trace or extract Tuya config if possible) and start the driver with startDriver RC command. Then you will get events and codes in OBK console:

OBK console log showing received RF codes and MQTT connection details

We may add more information or hex format for codes in the future, but the core functionality will remain the same.
Then, to handle events, use the event handler in autoexec.bat:


addEventHandler2 RC 591946 0 POWER TOGGLE

First argument is always RC, second is remote control code, third is held state - first press has 0 value, further repeats (when the button is held) have a value of 1 there.
If you don't know how to create autoexec.bat, see guide:
https://www.youtube.com/watch?v=kXi8S12tmC8

Comparison with Tasmota
For the comparison purposes, we've hooked ESP32 flashed with Tasmota to the same receiver:

Wi-Fi relay module with USB flasher connected, on a blue work surface

This way, both Tasmota and OBK can see the same signal:

OBK console screenshot showing RF code 0x90848 received in hexadecimal format

Screenshot from OBK console showing received RF codes 591944 using protocols 1 and 17

OBK currently uses decimal format for RF code, but a little conversion can clearly show us that the codes are matching, so both solutions are interchangeable.

Conversion of 90848 from hexadecimal to decimal: result is 591944

Sample device config (autoexec.bat)
Sample autoexec.bat was based on OBK documentation. It's designed to showcase control of both the same RF device (relays), and other devices directly via their IPs.
The procedure to create autoexec.bat is simple - we just test the remote with OBK console open to see what the code is, and then write the code down.
Autoexec.bat can be rerun without restarting OBK device in many cases, so it's easy to develop quickly.


// addEventHandler RC 1234 toggleChannel 5 123

// on first receive
// addEventHandler2 RC 1234 0 toggleChannel 5 123
// on hold
// addEventHandler2 RC 1234 1 toggleChannel 5 123

addEventHandler2 RC 591944 0 ToggleChannel 1
addEventHandler2 RC 591940 0 ToggleChannel 2
addEventHandler2 RC 591948 0 ToggleChannel 3
addEventHandler2 RC 591938 0 ToggleChannel 4

addEventHandler2 RC 591937 0 PowerAll 1

addEventHandler2 RC 591950 0 PowerAll 0

// sample of external device control
addEventHandler2 RC 591946 0 SendGet http://192.168.0.58/cm?cmnd=Power0%20Toggle

And here is short presentation - first control of the relays device itself:

Then usage of RF device as a gateway to control another device via HTTP GET - the LED strip controller is under the table, it's the device with 192.168.0.58 IP, as you can see in autoexec.bat:

Home Assistant support
We're also working on Home Assistant support - it should be released within upcoming days. The published RF format will match Tasmota standard, as can be seen there: https://tasmota.github.io/docs/RF-Protocol/

Summary
The following method should work with many RF receivers, including STX882 and so on. It allows you to reuse cheap 433 MHz RF hardware as a flexible automation input without relying on cloud services or vendor firmware. Thanks to event handlers and HTTP/MQTT integration, RF buttons can trigger virtually any action in your local network. The solution scales well, from simple relay toggling to complex multi-device scenes and automations. Combined with MQTT Home Assistant support, OpenBeken turns RF receivers into a powerful and fully open smart-home control layer.
Do you have any devices with RF inputs? Let us know!

About Author

p.kaczmarek2 wrote 13460 posts with rating 11290 , helped 617 times. Been with us since 2014 year.

Comments

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DeDaMrAz 15 Dec 2025 21:04

One thing to note is that the remotes that come with these type of devices are Princeton protocol RF remotes. OBK driver recognizes Roger protocol as well and we didn't test beyond that right now but it... [Read more]

divadiow 15 Dec 2025 21:35

great work guys! regarding this standard mini breaker/switch with RF on P8 https://obrazki.elektroda.pl/5081148700_1765829028_thumb.jpg https://obrazki.elektroda.pl/8964425900_1765829028_thumb.jpg... [Read more]

p.kaczmarek2 15 Dec 2025 21:40

By the way, do you remember those switches where 480RA RF receiver is connected to buttons controller MCU, and not to Wi-Fi module? Like there: https://www.elektroda.com/rtvforum/topic4110013.html I... [Read more]

divadiow 15 Dec 2025 23:04

well, yes, though it seems I do have one of those switch types but it does contain remote_io in the config - Bingoelec W601 T34 . On the other hand, the two other devices I posted about here do... [Read more]

p.kaczmarek2 16 Dec 2025 00:04

Ah, I think the board on photos has USB port, so it's 5 V powered, it's just that I found the 230V-powered version and put the schematic of that. Thanks for updating template! RC driver should be... [Read more]

FAQ

TL;DR: Flash a Tuya 4‑channel (433 MHz) relay with OpenBeken, map RCRecv, run startDriver RC, then bind button codes—“all basics covered.” [Elektroda, p.kaczmarek2, post #21781577]

Why it matters: This turns a cheap RF relay into a local, cloud‑free RF hub that can trigger Wi‑Fi devices, scenes, and Home Assistant automations.

Quick Facts

- Hardware demo: Tuya 4‑channel 220 V AC Wi‑Fi relay with SYN590R receiver and CB3S (BK7231) module. [Elektroda, p.kaczmarek2, post #21781577]
- Firmware: OpenBeken (OBK) supports an RC driver; start it with `startDriver RC` after assigning the RCRecv pin. [Elektroda, p.kaczmarek2, post #21781577]
- Event model: First press held-state=0; repeats when held=1; bind with `addEventHandler2`. [Elektroda, p.kaczmarek2, post #21781577]
- Interop: RF format aligns with Tasmota; OBK shows decimal codes that match Tasmota after conversion. [Elektroda, p.kaczmarek2, post #21781577]
- Integrations: Control local devices via HTTP/MQTT now; Home Assistant support is imminent with Tasmota-style RF format. [Elektroda, p.kaczmarek2, post #21781577]

What is OpenBeken and why use it here?

OpenBeken is open firmware for BK7231 modules. It adds an RF driver so the SYN590R receiver connects directly to the Wi‑Fi chip. You read button codes, then trigger relays or other devices over HTTP/MQTT. It avoids vendor clouds and works as a flexible RF-to‑Wi‑Fi bridge. “RF buttons can trigger virtually any action.” [Elektroda, p.kaczmarek2, post #21781577]

How do I flash the BK7231 (CB3S) module and detect the device template?

Use the BK7231 GUI Flash Tool from the OpenBeken project. The tool flashes the CB3S module and can auto-detect configuration. Import the detected template into OBK, then proceed to RF setup. Keep the console open to capture RF codes during testing. [Elektroda, p.kaczmarek2, post #21781577]

How do I enable the RF receiver and start seeing codes?

Trace the PCB to find the RCRecv pin, assign it in OBK, then run startDriver RC. Press a remote button and watch OBK’s console to see the decimal RF code and the held-state flag. Use those values in event handlers. [Elektroda, p.kaczmarek2, post #21781577]

What’s the quickest way to bind a remote button to a relay?

Three steps: 1) Capture the button code in the console. 2) Add to autoexec.bat: addEventHandler2 RC <code> 0 ToggleChannel <n>. 3) Save and re-run autoexec to test without rebooting. Map channels 1–4 as needed. [Elektroda, p.kaczmarek2, post #21781577]

Can I control other devices (like smart bulbs or LED strips) from this RF hub?

Yes. Use event handlers to send HTTP commands directly to device IPs, or publish via MQTT. The example shows an RF button toggling a Wi‑Fi LED strip at 192.168.0.58 using SendGet. This provides local, low‑latency control with no cloud. [Elektroda, p.kaczmarek2, post #21781577]

How does held vs. single press work in OBK’s RC driver?

OBK exposes a held-state parameter in events. First press sets the third argument to 0. Holding the button generates repeats with the value 1. Use addEventHandler2 to branch behavior by that flag. This enables press-and-hold actions. [Elektroda, p.kaczmarek2, post #21781577]

Does this approach work if the RF receiver is behind an external MCU?

If the SYN590R output goes into a separate MCU, the Wi‑Fi chip will not see raw RF data. OBK’s RC driver needs the receiver wired to a BK7231 pad. In MCU‑mediated designs, use the MCU’s protocol or modify hardware. [Elektroda, p.kaczmarek2, post #21781577]

How does OpenBeken compare to Tasmota for 433 MHz remotes?

The demo feeds the same RF signal to OBK and a Tasmota ESP32. After converting OBK’s decimal code, both match. This means remotes and automations are interchangeable. Upcoming HA support will follow Tasmota’s RF format. [Elektroda, p.kaczmarek2, post #21781577]

What is the SYN590R and why was it chosen?

SYN590R is a 433 MHz RF receiver used on the Tuya 4‑channel board. It connects directly to a BK7231 pad, making it ideal for OBK’s RC driver. This eliminates a middle MCU and reduces latency and complexity. [Elektroda, p.kaczmarek2, post #21781577]

What is Tuya in this context?

Here, “Tuya” refers to the showcased 4‑channel 220 V AC Wi‑Fi relay module sourced from AliExpress. It ships with one RF remote, and you can add more. The board carries a CB3S (BK7231) module and a SYN590R receiver. [Elektroda, p.kaczmarek2, post #21781577]

How do I structure an autoexec.bat for multiple buttons and scenes?

Use one line per button code. Example shows mappings for channels 1–4, plus all‑on and all‑off. Add HTTP calls to control other IP devices. You can re-run autoexec without rebooting for fast iteration. Keep codes readable and documented. [Elektroda, p.kaczmarek2, post #21781577]

Is there a Home Assistant integration?

Yes, support is being finalized. The published RF format will match Tasmota’s documented standard. That ensures simple pairing with existing RF automation flows in HA once released. Watch for builds in the coming days. [Elektroda, p.kaczmarek2, post #21781577]

What failures should I expect, and how do I debug them?

If no codes appear, verify the RCRecv pin mapping and that startDriver RC ran. Check whether the RF path goes through an external MCU, which OBK cannot read. Use the console to confirm codes and the held-state flag. [Elektroda, p.kaczmarek2, post #21781577]

Can one RF hub trigger multiple Wi‑Fi devices at once?

Yes. Use multiple addEventHandler2 lines for the same code to call several actions. You can toggle relays locally and fire HTTP/MQTT commands to other devices for scenes. This scales from one relay to whole‑home actions. [Elektroda, p.kaczmarek2, post #21781577]

Do I need internet or cloud accounts for this to work?

No. All examples use local networking. OBK handles RF reception on‑device, and actions run via local HTTP or MQTT. This yields privacy, resilience, and fast response even if the internet drops. [Elektroda, p.kaczmarek2, post #21781577]

What concrete example stats should I copy from the guide?

The sample uses RF codes like 591944–591950, mapping to four channels, all‑on, and all‑off. First press=0, hold=1. Reuse this structure with your own captured codes for consistent behavior. [Elektroda, p.kaczmarek2, post #21781577]