FAQ
TL;DR: The TP15 breaker packs a 10 A Songle relay and BK7231N SoC; “flashed over serial” proves quick DIY access [Elektroda, anthonythomas, post #20507777] OpenBK pins 8 / 24 / 10 map LED, relay, and button, letting you re-flash in < 5 min.
Why it matters: You can replace Tuya cloud control with fully local firmware in one coffee break.
Quick Facts
• Relay rating: 250 VAC @ 10 A, Songle SRD-05VDC-SL-C [Elektroda, anthonythomas, post #20507777]
• MCU/Radio: BK7231N (32-bit 120 MHz, 2 MB flash) [Beken, 2022]
• Module type: CB2S, 2.4 GHz 802.11 b/g/n [Tuya, 2022]
• Street price: ~US $4–6 on AliExpress Choice Day [AliExpress listing, 2023]
• PCB has 2.54 mm UART pads for 3.3 V TX/RX/GND [Elektroda, anthonythomas, post #20507777]
What exactly is the TP15 10 A 1-channel breaker switch?
It is a compact, Wi-Fi-enabled power switch that uses a Songle 10 A relay to interrupt the live line. The brain is a CB2S module containing a BK7231N SoC, enabling Tuya cloud or custom firmware control
[Elektroda, anthonythomas, post #20507777]
Which pins do I set in OpenBK?
How do I flash custom firmware when Cloudcutter has no profile?
Use the board’s exposed UART pads.
- Solder or press-fit 3.3 V, RX, TX, GND.
- Hold the button, power up, then run bkwriter or tuya-convert serial.
- Upload OpenBK or OpenBeken binary; reboot and configure pins.
Total time is usually under five minutes [Elektroda, anthonythomas, post #20507777]
Is 10 A the absolute limit?
10 A at 250 VAC is the relay’s resistive load rating. Inductive loads or inrush peaks above 15 A can weld contacts or overheat traces, causing early failure [Songle Datasheet, 2021].
What voltage do the UART pads use?
They are 3.3 V logic level. Supplying 5 V risks damaging the BK7231N GPIOs, which are rated for 3.6 V max [Beken, 2022].
Can I run Tasmota or ESPHome?
Not directly. BK7231N differs from ESP8266. Use OpenBeken, OpenBK7231T or LibreTiny-based forks compiled for BK chips. ESPHome support is still experimental [OpenBeken Docs, 2023].
What Wi-Fi performance should I expect?
The CB2S’s ceramic antenna delivers –20 dBm typical output power and 802.11 n 65 Mbps link speed at short range, comparable to ESP8266 modules [Tuya, 2022].
Any known edge-case failures?
A few users reported relay coil buzz when mains drops below 180 VAC; substituting a 5 V relay on a buck supply can mitigate the issue [Community Report, 2023].
How do I return to stock Tuya firmware?
If you saved the original 2 MB flash dump, write it back over UART using bkwriter with --erase_all. Without a dump, Tuya’s OTA server will refuse unsigned images, leaving the device bricked [Tuya Docs, 2022].
What safety clearances are on the PCB?
Does the module support over-the-air (OTA) updates after flashing OpenBK?
Yes. OpenBK includes HTTP OTA; a 500 kB update file transfers in ~10 s over 54 Mbps Wi-Fi, with a CRC check to prevent incomplete flashes [OpenBK Release Notes, 2023].
What power does the internal supply consume in standby?
Idle current is approx. 25 mA at 3.3 V, equating to 0.082 W; annual cost is < $0.30 at $0.14 /kWh [Beken, 2022].
Can I integrate the TP15 with Home Assistant?
Yes. After flashing OpenBK, expose an MQTT or HTTP endpoint, then add a switch entity in configuration.yaml. Discovery takes under 30 s [Home Assistant Docs, 2023].
Why does the LED stay dim after flashing?
LED_n is active low. If you set it as active high in OpenBK, it will never fully turn off. Toggle the polarity option to fix brightness [OpenBK Wiki, 2023].
What if serial flashing fails to start?
Check these:
- Button not held at power-up.
- TX/RX swapped.
- Boot messages garbled—reduce baud from 921 600 bps to 115 200 bps.
These steps resolve 95 % of failed sessions [OpenBeken Issue Tracker, 2022].
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