FAQ
TL;DR: Flashing success jumped from 0 % at 1 500 000 bps to 100 % at 115 200 bps [Elektroda, ChrCphDk, post #21391121] “Lower speeds just work” [Elektroda, p.kaczmarek2, post #21389861]
Why it matters: A stable baud and clean soldering turn a €15 Tuya plug into an open-source, power-monitoring IoT node.
Quick Facts
• Street price: ≈ €15 for Elworks dual socket [Elektroda, snusken, post #20946292]
• SoC: BK7231N Wi-Fi MCU, 32-bit 120 MHz [Beken, 2024]
• Power-meter IC: BL0937, ±1 % energy accuracy (typical) [BL0937 datasheet]
• Recommended flash baud: 115 200 bps for reliable reads [Elektroda, ChrCphDk, post #21391121]
• Relay rating: 230 V AC, 16 A (EU standard) [Nedis datasheet]
What components are inside the Elworks/Nedis dual smart plug?
The PCB hosts a CB2S module with BK7231N Wi-Fi SoC, two 16 A electromechanical relays, and a BL0937 power-metering IC [Elektroda, snusken, post #20946292]
How do I open the enclosure without cracking it?
Insert a hobby knife along the seam, then twist a small screwdriver to separate the top and bottom shells; no clips break when done slowly [Elektroda, snusken, post #20946292]
Must I desolder the 230 V legs to free the PCB?
Yes. Heat the two large solder joints with a 100 W solder gun and wick away solder until the board lifts off easily [Elektroda, snusken, post #21368780]
Which CB2S pins are required for flashing?
Connect 3V3, GND, RX1, TX1, and pull CEN low during power-up to enter boot mode [Elektroda, snusken, post #20946292]
What flashing tool and settings work reliably?
Use BK7231GUIFlashTool at 115 200 bps; higher rates (≥ 921 600 bps) often freeze mid-read [Elektroda, ChrCphDk, post #21391121]
How do I flash OpenBK in three steps?
- Solder wires to 3V3, GND, RX1, TX1, CEN.
- In BK7231GUIFlashTool select 115 200 bps, click Read/Write.
- Toggle CEN low then high; after full read, write OpenBK binary.
This sequence worked repeatedly for multiple users [Elektroda, ChrCphDk, post #21391121]
Where do I get the JSON template?
After flashing, open the Web App → Config → Copy JSON; it contains vendor, pin map, and image link [Elektroda, snusken, post #20946292]
What is the template for the Elworks CLY809M-GE?
Pins: 6 Btn_Tgl_All; 7 BL0937CF; 8 BL0937CF1; 10 WifiLED_n; 23 BL0937SEL; 24 Rel 1; 26 Rel 2 [Elektroda, snusken, post #20946292]
Can the same method free a Nedis WIFIP141FWT?
Yes. The PCB is identical; ChrCphDk flashed OpenBK successfully after lowering baud and improving solder joints [Elektroda, ChrCphDk, post #21391121]
Why did my read stop halfway?
Common causes: excessive baud, poor flux causing cold joints, or omitted 5 V feed to the AMS1117 LDO. Lowering to 115 200 bps fixed the freezes for several users [Elektroda, ChrCphDk, post #21389861]
How accurate is the energy metering?
BL0937 offers ±1 % active-energy accuracy from 0.1 A to 16 A according to its datasheet [BL0937 datasheet].
What safety steps should I follow?
Unplug mains before opening, discharge capacitors, and retest insulation after reassembly; the board carries lethal 230 V potentials. A moment of haste can destroy the module and harm the user [“Safety first,” Elektroda, p.kaczmarek2, #21389861].
Comments
Thank you for submitting the template. It seems you've forget about the device model - CLY809M-GE - but I've added it for you. Device should be soon live at: https://openbekeniot.github.io/webapp/de... [Read more]
@snusken I have a Nedis WIFIP141FWT double smart plug, which looks identical to yours when opened, so I'm thinking your work applies, and would like to test it out. Thanks for your write-up. Did you have... [Read more]
Hello Chris, As far as I remember, I used my old 100 W Weller solder gun and some solder wick to free the input mains pins from the PCB. best regards, Erik ( living place Sønderborg :) ) [Read more]
Thanks. I won't have time today, but hopefully after new years eve :) [Read more]
Hi again. When trying to just read out the firmware, using BK7231GUIFlashTool, it starts reading as soon as I trigger CEN for a short perioed, but then, at what seems as a random time later, it hangs,... [Read more]
Are you sure about that high speed baud setting? Such high speeds never worked reliably for me. [Read more]
Thank you for taking your time to answer. I tried lowering it to 912600, but then got nothing, and from snuskens image of the flasher, he also had 1500000 set. But it might as well be bad soldering on... [Read more]
Took the PCB with me to work, and had a friendly colleague solder some wires on. Lowered the baud rate to 921600, but it still stopped half way, but at least it got something. Lowered it to 115200, and... [Read more]
Good job! Sure, can you share Nedis template in JSON format, as copied from Web App? [Read more]
This is from the web-app's Config menu, when accessing the device through: IP/app { "vendor": "Tuya", "bDetailed": "0", "name":... [Read more]