FAQ
TL;DR: Tuya PJ-1103A handles up to 80 A and can be OTA-flashed in under 2 min; “It should be possible to link old BL0942 energy stats to TuyaMCU” [Elektroda, p.kaczmarek2, post #21164859] Update rate adjustable to 3 s via dpID 129.
Why it matters: Rapid, cloud-free energy data lowers home-automation latency.
Quick Facts
• Measurement range: 0.2 – 80 A, 110–240 V AC [Elektroda, taktlos, post #20828178]
• Wireless: 2.4 GHz Wi-Fi, BK7231N/CB2S module [Elektroda, taktlos, post #20828178]
• Flash method: CloudCutter OTA, profile “tuya-generic-pj-1103a-energy-meter” [Elektroda, taktlos, post #20828178]
• Reporting interval: 3 – 60 s via dpID 129 (default 10 s) [Elektroda, alexan_e, post #21400668]
• Calibration coefficients: 800 – 1200 (voltage/current/power), stored in dpIDs 116-128 [Elektroda, alexan_e, post #21400668]
What chips and sensors does the PJ-1103A use?
Most retail units combine a BK7231N Wi-Fi SoC on a CB2S module with a HLW8112 dual-channel metering IC; older sub-variants used TuyaMCU plus BL0942 [Elektroda, taktlos, #20828178; alexan_e, #21377847].
How do I jailbreak and flash OpenBeken OTA?
- Run Tuya CloudCutter, select profile “tuya-generic-pj-1103a-energy-meter”.
- Upload OpenBeken-v1.17.262_bk7231n.ug.bin.
- Reboot; create autoexec.bat to load TuyaMCU driver and map dpIDs [Elektroda, taktlos, post #20828178]
Which dpIDs map to the main electrical values?
Voltage 112, Current 113/114, Power 101/105, Frequency 111, Energy Fwd/Rev A 106/107, Energy Fwd/Rev B 108/109, Total Energy 130/131, Reporting rate 129 [Elektroda, alexan_e, post #21400668]
tuyaMcu_sendQueryState every 5 s still shows few updates—why?
The MCU itself limits how often it pushes fresh registers. Manual polling does not bypass its internal 10 s sample window, so extra commands yield identical data [Elektroda, taktlos, post #20837502]
Can cumulative energy be handled like the BL0942 driver?
Not yet. “TuyaMCU may not provide frequent enough updates for it to work good. It is currently not implemented” [Elektroda, p.kaczmarek2, post #21164859]
How can I display direction channels as enums instead of text hacks?
Enums require a dedicated channel type. The maintainer confirmed it can be added for dpIDs 102 and 104, but the feature is still pending [Elektroda, p.kaczmarek2, post #21164859]
Is there a native OpenBeken driver for HLW8112?
Development has begun (branch drv_hlw8112) and basic SPI communication works, but register writes can fail (error at reg 0x80) and no stable readings yet [Elektroda, dicamarques, #21333858; nhsqr, #21333875].
What causes the “Failed to write reg 80 val A04” boot error?
The HLW8112’s SPI_EN pin or CLK/MISO/MOSI lines are mis-routed or clocked while the chip sleeps. Confirm CS low, SPI_EN high, and 2 MHz clock. Edge-case logs show read 0x410000 instead of 0x0 A04 [Elektroda, nhsqr, post #21333875]
How do I calibrate voltage and current?
Set dpID 116 to 800-1200 for voltage, 117/123 for current A/B, and 118/124 for power. Use known loads, then issue SetChannel <dpID> <coef>; coefficients persist in flash [Elektroda, alexan_e, post #21400668]
What is the smallest reporting interval?
dpID 129 accepts values down to 3 s; anything lower is ignored by firmware [Elektroda, alexan_e, post #21400668]
Does the meter lose energy totals after a blackout?
Forward and reverse totals (dpIDs 130, 131) survive power loss, but some per-channel counters reset—an observed edge case on early firmware 1.0.10 [Elektroda, rohanb, post #21157458]
I lost my Tuya backup—can I restore stock firmware?
Yes. Another full dump from the same hardware (link in post #21212779) can be flashed with BKWriter. Device-specific UUID/keys regenerate on first boot [Elektroda, divadiow, post #21378170]
What else is needed after `startDriver HLW8112SPI`?
Map the SPI pins in pinRole, reboot, then run EnergyMeter_Init HLW8112 and assign channel types. Without proper pin mapping, register writes fail and all readings show zero [Elektroda, paulkayBlack6spdZ, post #21390310]
Typical cost and availability?
Aliexpress listings range from US $18–25 for 1-CT units and US $24–30 for dual-CT versions (March 2025 search). Prices include two 80 A clamps and shipping to EU [Aliexpress listing ID 1005005861421515].
