FAQ
TL;DR: The NOVADIGITAL CB2S (BK7231N) outlet’s BL0937 uses 3 metering pins (CF, CF1, SEL); if CF is wrong, power shows 0. As one expert notes, "CF1 reads current/voltage." [Elektroda, max4elektroda, post #21807434]
Why it matters: This FAQ helps OpenBeken users fix missing/incorrect BL0937 pinouts and get real power readings on this Tuya-based outlet.
Quick-Facts
- Pin map from dump: SEL→P8, CF1(VI)→P7, CF(ELE)→P6, Wi‑Fi LED→P10, Button→P26, Relay→P24. [Elektroda, tadeu1, post #21807160]
- Metering requires CF, CF1, and SEL; CF gives power, CF1 gives V/I selected by SEL. [Elektroda, max4elektroda, post #21807434]
- OpenBeken keeps old pins until you stop the driver or restart after changes. [Elektroda, max4elektroda, post #21807524]
- Tuya blob: module CB2S/BK7231N; Tuya section offset ≈2,023,424 bytes. [Elektroda, tadeu1, post #21807160]
- In OBK, inverted signals use the “_n” suffix (e.g., BL0937SEL_n). [Elektroda, max4elektroda, post #21807422]
Quick Facts
- Pin map from dump: SEL→P8, CF1(VI)→P7, CF(ELE)→P6, Wi‑Fi LED→P10, Button→P26, Relay→P24. [Elektroda, tadeu1, post #21807160]
- Metering requires CF, CF1, and SEL; CF gives power, CF1 gives V/I selected by SEL. [Elektroda, max4elektroda, post #21807434]
- OpenBeken keeps old pins until you stop the driver or restart after changes. [Elektroda, max4elektroda, post #21807524]
- Tuya blob: module CB2S/BK7231N; Tuya section offset ≈2,023,424 bytes. [Elektroda, tadeu1, post #21807160]
- In OBK, inverted signals use the “_n” suffix (e.g., BL0937SEL_n). [Elektroda, max4elektroda, post #21807422]
What’s the correct BL0937/CB2S pinout for this outlet?
From the extracted config: BL0937 SEL→P8, VI/CF1→P7, ELE/CF→P6; Wi‑Fi LED→P10; Button CH1→P26; Relay CH1→P24. [Elektroda, tadeu1, post #21807160]
Why do I see 0 W power but changing voltage/current?
CF likely goes to the wrong pin or is disconnected. CF outputs power pulses; CF1 outputs V/I depending on SEL. If CF is wrong, watts stay at 0 even when V/I move. "CF1 reads current/voltage." [Elektroda, max4elektroda, post #21807434]
Do I need to restart OpenBeken after changing BL0937 pins?
Yes. The driver continues with previous pins until you stop it or restart the device. After editing pins, stop the BL0937 driver or reboot to apply. [Elektroda, max4elektroda, post #21807524]
How do I calibrate readings in OpenBeken?
Use the Web App’s Tools page to run calibration. Confirm that values change slightly while adjusting. If not, revisit pin mapping first. [Elektroda, max4elektroda, post #21807198]
Is there an inverted SEL option in OBK?
Yes. OpenBeken uses the “_n” suffix for inverted signals, such as BL0937SEL_n. This mirrors what you might know as “inverted” in other firmware. [Elektroda, max4elektroda, post #21807422]
What does the Tuya dump tell me about this device?
It’s a CB2S module with BK7231N. The Tuya config section begins near byte offset 2,023,424. Use that offset if you parse the blob again. [Elektroda, tadeu1, post #21807160]
I cleared pins but still see meter values—bug?
Not a bug. The BL0937 driver keeps running with old pins until you stop it or restart. Clear pins, stop driver, then reboot. [Elektroda, max4elektroda, post #21807524]
Can I test only the relay and button while metering is broken?
Yes. Map Relay→P24 and Button→P26 to verify switching and input. Meter tiles may still display until you stop/restart the driver. [Elektroda, tadeu1, post #21807519]
My multimeter shows no continuity on CF/CF1/SEL—what next?
Reinspect solder joints and follow traces visually. The user saw GND/3.3 V continuity but none on CF/CF1/SEL. Recheck routing from BL0937 to CB2S pads. [Elektroda, tadeu1, post #21807560]
Quick steps: How do I apply new BL0937 pins cleanly?
- Stop the BL0937 driver in the Web App.
- Set CF, CF1, and SEL pins, then save.
- Restart the device to load the new mapping. [Elektroda, max4elektroda, post #21807524]
What do CF, CF1, and SEL actually do?
CF outputs active power pulses. CF1 outputs either current or voltage. SEL chooses whether CF1 reports current or voltage at any moment. [Elektroda, max4elektroda, post #21807434]
Can SEL make voltage and current appear swapped?
Yes. If SEL is inverted or mis-set, CF1 will report the opposite metric. Expect V/I to exchange until SEL is corrected. [Elektroda, max4elektroda, post #21807422]
Which channel pins control relay and button on this unit?
Relay channel 1 uses P24. Button channel 1 uses P26. These matched both the JSON and on-device tests. [Elektroda, tadeu1, post #21807160]
What protection thresholds does the extracted config show?
Typical values found: over-current 21000 (units from OEM), over-voltage 265, and low-voltage 96. Treat as starting points; verify during calibration. [Elektroda, tadeu1, post #21807160]
