How do I free the PJ-MGW1103 energy meter from the cloud and connect it to Home Assistant?

Almost, there is one more step needed - you need to check SEL pin state to see if it's set to UART or SPI. Change it if needed.

Quote:

7 SEL UART/SPI mode selection (0: UART 1: SPI), internal pull-down resistance,
connected to GND is 0 level (UART), connected directly to VDD is high level (SPI)

You also need to pay attention to SCLK_BPS:

Quote:

8 SCLK_BPS Serial Clock input for SPI. If using UART, this pin is used to config baud rate of
UART

Last night I tried your firmware and the device still showed weird readings so I proceed to a proper visual inspection of the PCB, using the microscope this time. It didn't take long until I found the culprit: resistor and capacitor on one input of the BL0942 is cracked. It's possible I somehow cracked them when I first open the device to flash it. Embarrassing, never happened to me until now...

I will try to replace these components and see if the calibration is still accurate. It's a shame I don't have 0402 smd components in my inventory

At least I am happy I found out why it was behaving like this... it drove me crazy not understanding why...

Thank you very much for your time and support and for the whole "open beken project", it's amazing!

Just to confirm, I have replaced the broken components and the device is working great now!
And for reference the resistors are 470R and capacitors are 68nF - (on the input pins 2 and 3 of the BL4092)

That's good to know, I didn't consider that. So now it also works good with OBK?

Yes, now it works good with open beken.

Added after 9 [minutes]:

Yes, now it works good with open beken.

Dont know if i can ask this here but:

- I had this device die on me.
- Removed the CB2S and tried to make a back up alwasy giving the same error of CRC mismatch with differente values.
- Since it was bad, i assumed it was corrupted and flashed anyways. The flash is correctly verified, but it doesnt get too hot when plugged and it never created the AP.

- I had an used WB2S (from a bulb). I could back it up and flash it and it creates the AP.
- The thing is while it get sent the startdriver tuyaMCU command it doesnt give info back.

Should/would the WB2S work as a drop-in module? (the original P24 and P26 on CB2S are now PWM4 and PWM5 in WB2S)
If it should, do i need to rewire the pins from the PWM4 and PWM5 to other pads or can it be just configured from the web app?
Which command should i use for seeing the info that i get from the device? currently the "tuyaMcu_sendQueryState" says OK but doesnt show anything back, same with "uartSendHex 55AA0008000007"

Well, i went for it. I'll leave this here in case it's useful to anybody. Since i had no communication with the Tuya MCU chip (U6 empty space near the RX pad at the end of the black wire) and soldered the BL0942 directly to the CB2S (Tx -> Rx and viceversa), through the test pads in the board as pictured:



As startup command, i used (I assume this is the same as autoexec.bat(?)):

startDriver BL0942
PowerSave 1

SetupEnergyStats 1
EnergyCntSample 1

and has been working OK through MQTT on home assistant. It has quite more entities than what i remember from the Tuya App:



Since it worked as is, i assume the BL0942 it's configured in uart mode by default.

scattering wrote:

PowerSave 1

edit disregard it, I had outdated info, it works now good in OBK

>>21852105
Wasn't this BL0937 problem?
How would it cause trouble for BL0942, considering it uses UART?

And BL0937 problem on BK+powersave was fixed quite a while ago.

>>21852105

Thanks, i had no idea.

Indeed there's some info online. Since i'm not actively using it right now and it's not totally clear if it causes issues or not (both insmod comment as info online mentioning newer firmware or even hardware issues) i'll put it in series with another device and check if the measurements are consistent or not (ofc that would just describe how my specific unit ebhaves but it's better than nothing).

insmod wrote:

Wasn't this BL0937 problem?
How would it cause trouble for BL0942, considering it uses UART?

And BL0937 problem on BK+powersave was fixed quite a while ago.

My bad then, I had outdated info, I apologize.