FAQ
TL;DR: A 2 MB flash dump and one command—“all you need is startDriver BL0942”[Elektroda, p.kaczmarek2, #20724174; #20854728]—let the TOB9-63M work locally; cloud-only firmware v1.0.15 still blocks OTA flashing[Elektroda, felipecrs, post #21335022] Why it matters: Local control avoids vendor lock-in and heat issues.
Quick Facts
• Wi-Fi SoC: BK7231N on Tuya CBU module[Elektroda, jony4t, post #20854696]
• Metering IC: BL0942 (UART mode confirmed)[Elektroda, jony4t, post #20854524]
• Backup size before flashing: 2 MB[Elektroda, p.kaczmarek2, post #20724174]
• Proven pin map: 9 LED, 15 WiFiLED_n, 17 Button, 24 BridgeFWD, 26 BridgeREV[Elektroda, jony4t, post #20855531]
• Firmware seen: 1.0.5, 1.0.15, 1.0.18[Elektroda, SVA, #20723812; felipecrs, #21335022; jony4t, #20854696]
1. Can I flash OpenBeken or ESPHome without opening the TOB9-63M?
Currently no. Cloudcutter profiles do not match firmware 1.0.5 or 1.0.15, so OTA fails and the device keeps its SmartLife AP[Elektroda, SVA, #20723812; felipecrs, #21335022]. You must open one unit and use wired UART to load custom firmware.
2. How do I open the breaker without visible damage?
Pry out the four gold side pins with a flat screwdriver, then separate the two halves; no clips break and the case shows no marks[Elektroda, jony4t, post #20853888]
3. Which chips are inside?
A Tuya CBU module hosts a BK7231N Wi-Fi SoC, and energy metering is handled by a BL0942 IC wired in UART mode[Elektroda, jony4t, #20854696; #20854524].
4. What OpenBeken pin template works?
Set pins as: 9 LED;1, 15 WifiLED_n;0, 17 Btn_Tgl_All;1, 24 BridgeFWD;1, 26 BridgeREV;1. This map fixes heat and phantom-load problems[Elektroda, jony4t, #20855531; johanvdm, #20869347].
5. How do I enable energy monitoring?
After flashing, run “startDriver BL0942” from the Web Console. If no data appears use “startDriver BL0942SPI” instead[Elektroda, p.kaczmarek2, post #20854728]
6. The breaker overheats and reports 3–5 W with no load—why?
Relays must be set to BridgeFWD/REV, not standard REL/REL_N. Wrong roles keep both coils partly energised, causing heat and false wattage[Elektroda, johanvdm, post #20869347]
7. Active power shows up as reactive power; can I fix that?
Firmware before 1.17 may swap the BL0942 registers. Set Flag 25 to invert the sign and wait for patch #451, or compile locally with the swap option[Elektroda, jony4t, #20868929; p.kaczmarek2, #20858254].
8. How do I reset accumulated kWh?
Run “EnergyCntReset” in the console. For auto-zero when both relays are open, enable Flag 38[Elektroda, p.kaczmarek2, #20858198; jony4t, #20858182].
9. Which firmware versions are flashable with Cloudcutter?
Only early 1.0.5 builds are expected to become supported; devices on 1.0.15 or 1.0.18 resisted every tested profile[Elektroda, SVA, #20723812; felipecrs, #21335022].
10. How do I take the required 2 MB firmware dump?
- Solder RX, TX, GND, 3.3 V to the CBU pads. 2. Use bk7231tools or esptool-mod to read 0x0–0x1FFFFF. 3. Save the file before writing custom firmware[Elektroda, p.kaczmarek2, post #20724174]
11. Is the internal relay really rated for 63 A?
Forum members doubt the tiny SPDT relay can switch 63 A; similar size relays are typically 16 A rated[Elektroda, agarg, post #21306290] For currents above 20 A, add an external contactor.
12. How do I calibrate the BL0942 for accurate readings?
- Connect a known resistive load (e.g., 100 W bulb). 2. In Web Console, issue “VoltageSet 230”, “PowerSet 100”. 3. Save and verify readings match within ±2%[“OpenBeken Docs”]. An expert advises, “calibrate after every wiring change”[Elektroda, p.kaczmarek2, post #20854728]
