Tuya WiFi Energy Meter PM01_A002 [CBU][BK7231N] HLW8112 SPI Power Reading Ratio 1:5?

For information on mine I need to overwrite the bootloader for boot OK.
I cannot flash it anymore, but it works!

I am using OpenBK7231N_1.18.206_hlw8112.rbl on a device like the one in the first post.
It works very well.
Is there a way to correct the measurements within very small limits?
The VoltageSet command does not work.

Interestingly, after flashing the new firmware, my device is reporting current readings exactly 5× higher than the actual values. Is there a way to recalibrate the scaling factor or apply a correction offset in the configuration? Thank you!

I am not the author of HLW8112 integration, but in OBK, we have VoltageSet/CurrentSet/PowerSet commands. We may need to check the source code for HLW8112 to be sure, but calibration is a standard procedure, like with Tasmota.
Is this the driver used?
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/src/driver/drv_hlw8112.c
It looks like the author added some extra commands - something like HLW8112_SetResistorGain.

>>21794549 Thank you for the reply. I tried running some HLW8112 custom commands, but it looks like they aren't supported yet. I noticed a 'TODO' status in the code/documentation—am I interpreting that correctly?

Also, the standard VoltageSet/CurrentSet/PowerSet commands are returning errors.

This does not mean that they are not supported. It means there is no docs for them yet. The author of HLW8112 SPI feature didn't fill their descriptions.

>>21795260 I managed to get it working. Using the command HLW8112_SetResistorGain 1 1000 1 caused the voltage readings to spike into the thousands. However, after running HLW8112_SetResistorGain 0 1000 1, the voltage returned to normal and the current readings became accurate (instead of being 5× too high).

I also noticed a channel mismatch: my current clamp is physically connected to Channel A, but the interface displays the data on Channel B. If I plug the current clamp into Channel B, the interface shows no reading at all.

I’m not sure who the original author of these HLW8112 drivers is. I tried reading through the forum thread, but it got a bit confusing—does anyone know who I should contact with questions?

https://github.com/openshwprojects/OpenBK7231T_App/pulls?q=HLW8112
https://github.com/openshwprojects/OpenBK7231T_App/pull/1810/changes

>>21795325 As a non-coder, where is the best place to get support — here or GitHub? Thanks.

Well, usually the best place to get quick support is here (on Elektroda), but for HLW8112 the case is special, because for some question you may want to reach for PR author.

maxters007 wrote:

Hey @p.kaczmarek2 I have created a PR https://github.com/openshwprojects/OpenBK7231T_App/pull/1810
driver is disabled in the code. please have a look and let me know

@maxters007 are VoltageSet/CurrentSet/PowerSet commands working in your driver? Can you add command descriptions?

>>21795356 Ah, I see—the manufacturer swapped the labels for Channel A and Channel B on the outer case compared to the actual circuit board.

@maxters007

Was

HLW_8112_SCSN

intentional, or is it just a typo of

HLW8112_SCSN

? I’m asking because the parser accepts the underscored form, but I want to know which name you consider canonical and whether accepting both would be the right fix or if there should be an adjustment to a single one - my preference would be

HLW8112_SCSN

.