[Solved] OpenBeken - new BL0942 device is not receiving any data from energy meter

Hello

I just received a Power Monitor Switch 16A Wifi Smart Switch with BL0942
from this seller
https://www.aliexpress.com/item/1005005134537878.html?spm=a2g0o.cart.0.0.448138daZoou4E&mp=1

I have though an issue with the power monitor since I have zero values.


All functionality of the gang works as expected. I have firmware 1.15.659 though I have tested some more old ones.

Any thoughts ?

How do you know it's really BL0942? Have you opened the case?

Added after 54 [seconds]:

I have firmware 1.15.659 and I get a reading:

Hello

Yes, I have opened the case.

Have a look at the photo also

Do you have any BL0942 messages in the Web App log?

BL0942 can also use SPI interface sometimes. BL0942 can also sometimes use different baud rate.

Hello

Have no logs from BL0492. Following are the msg when I toggle the switch and also try to a reference on the voltage and Watts from tools section.

Info:CMD:[WebApp Cmd 'logfeature 7 1' Result] OK
Info:CMD:[WebApp Cmd 'logfeature 7 0' Result] OK
Info:MQTT:Channel has changed! Publishing 1 to channel 1
Info:MQTT:Publishing val 1 to switch16A-1/1/get retain=0
Info:CFG:####### Flash Save Channel 1 as 1 #######
Info:MQTT:MQTT client in mqtt_incoming_publish_cb topic switch16A-1/1/get
Info:MQTT:MQTT in topic switch16A-1/1/get
Info:MQTT:MQTT topic not handled: switch16A-1/1/get
Info:MQTT:channelSet NOT 'set'
Info:NTP:Seconds since Jan 1 1900 = 3889764734
Info:NTP:Unix time : 1680786734
Info:NTP:Local Time : 2023/04/06 13:12:14
Error:CMD:cmd LED_Map NOT found (args )
Info:CMD:[WebApp Cmd 'LED_Map' Result] Unknown command
Info:EnergyMeter:VoltageSet: you gave 230.000000, set ref to 0.000000
Info:CMD:[WebApp Cmd 'VoltageSet 230' Result] OK
Info:NTP:Seconds since Jan 1 1900 = 3889764795
Info:NTP:Unix time : 1680786795
Info:NTP:Local Time : 2023/04/06 13:13:15
Error:CMD:cmd LED_Map NOT found (args )
Info:CMD:[WebApp Cmd 'LED_Map' Result] Unknown command
Info:EnergyMeter:PowerSet: you gave 8.000000, set ref to 0.000000
Info:CMD:[WebApp Cmd 'PowerSet 8' Result] OK

Where are the TX, RX and BPS pins of BL0942 connected?


BPS is used to select UART baud rate. Maybe your device is a non-standard one and has higher baud selected...

Hello

I found the following :

BL0942 BK7231N
tx -> GND
RX -> TX
BPS -> ??? No connection

Are you sure? If BL0942 TX is shorted to ground, then it's not possible to get any result readings from BL0942....

I have the same problem with the switch. I get 0 as well

Hello, do you get any BL0942 logs?

Which software version?

Here's how it looks like on my LSPA9:



If you are not receiving data, then something must have changed in Tuya circuit. Please provide good quality photos and tell me how is BL0942 connected.
Maybe someone can sketch a schematic?

Maybe they changed default baud rate setting?

Hello

My switch is same as per https://www.elektroda.com/rtvforum/topic3965530.html (user piratee)
I see he had also some issues to read the energy values (https://www.elektroda.com/rtvforum/topic3965530.html#20522075) .. Did he manage to get them displayed?
I am still struggling to find a solution as I have still 0 on all energy values.
Best Regards

Let's start with voltage, current and power. Do you get them read correctly?

They are working for @piratee as far as I know. Are they?

Hello

I have 0 on all values.

The BL0942 driver works right now for my LSPA9 socket, so it must be a hardware issue.

1. @thanos_kalos - do you get that sometimes in Web App log?


2. @thanos_kalos

thanos_kalos wrote:

BL0942 BK7231N
tx -> GND
RX -> TX
BPS - > ??? No connection

it is not possible that TX is connected to GND. It would never work. If that's really on GND potential, then something is wrong.



3. @thanos_kalos
if you have time, you can also try some older release, idk, a release from about a two months ago or so, I don't know, but again, I don't think it's a firmware issue, but who knows...

>>20529376
Hi.
My version with BK7231N with a chip on the board was damaged during testing. Now I have a Mini Smart DIY Switch I have with a chip on a board placed vertically.
Without a probe, the power measurement on the Mini Smart DIY starts.

Regards

@piratee which OBK version do you have? I am asking just to be sure.

We need to figure out why BL0942 is not working for some users.

@p.kaczmarek2
I am currently using two versions:
- Build on Apr 2 2023 09:24:14 version 1.15.643
- Build on Apr 6 2023 10:49:30 version 1.15.660
Power measurement was correct on both.
Regards

Hello

I have used 1.15.660 and 1.15.256 but still have zeroes.
I start thinking that I might be facing a hardware issue. Unfortunately, I did not test the switch's energy values upon receiving with the Tuya app. I tested only the toggle functionality.

Can I revert back to the original firmware so I can rule out any H/W related issues?

Thanks for your support so far.

As I said, maybe they are using SPI or something else for that BL0942, who knows. A schematic would help a lot.

Do you have original firmware backup?

Hello

I have no backup of the original. I was thinking of using the one from piratee.

Can I upload directly from OTA ?

Regards

I don't think that the following check will give us any meaningful results.
We already know that current OBK works for @piratee but doesn't work for you. If you have different hardware configuration, then a flash backup from @piratee won't work for you anyway.
You would need to have the original flash backup from your device. Then it would be helpful for us to see if original firmware works.

In order to flash firmware backup, you would need to connect UART programmer. Then you can use BK7231 flash GUI tool, but only if you rename backup binary and put it into the firmware folder. Make sure to use proper chip type (T or N), or you might brick your chip. All other settings should be done automatically. Just select T or N.

Another helpful thing may be a sketch of BL0942 connections. Is TX of BL0942 really shorted to ground?

>>20530907


I found the problem with me and it was a cold solder joint that arose when desoldering the cable for flashing. I just re-soldered the chip.

Hello

Correction

BL0942 BK7231N
TX -> RX
RX -> TX
BPS -> ??? No connection

Just noticed that the RX on BK7231N is on GND

Regards

priorsoeren93 wrote:

I found the problem with me and it was a cold solder joint that arose when desoldering the cable for flashing. I just re-soldered the chip.

It certainly makes sense. Btw, for that kind of device, please put a PowerSave 1 in short startup command (use backlog if you need multiple commands), to reduce power consumption because cheapest devices have low quality power supplies that wear out quickly.

thanos_kalos wrote:

Just noticed that the RX on BK7231N is on GND

If RX is really shorted to ground, then it's impossible for BL0942 to work. Please figure out where the short is. Something must be shorting RX line to ground.
Did you program this device by wires?

Hello

Yes I did the flashing with wires since on using the CloudCutter I made the mistake and installed the T firmware instead of the N.
I did re-solder the BK chip and managed to not have a short between RX and GND. Now for BL0942 TX -> RX and RX -> TX with no grounding.

Now I have data.

I suggest to close the topic.

Thanks for your time and effort.

Regards

thanos_kalos wrote:

Now for BL0942 TX -> RX and RX -> TX with no grounding.

Do you get BL0942 logs in Web App now?

If you get them now, maybe you just need to recalibrate.

Works...



Please close the issue.
Sorry for the trouble. You are doing excellent work.

Regards

No problem, I am here to help, just remember to do a final calibration for Voltage, Current and Power.

And don't forget about PowerSave 1 for devices with low quality power supplies.

I did mess up with the soldering of the wires on the BK chip and shorted the RX with GND.

A careful re-solder solved the issue.

It's important to check the soldering job with multimeter for shorts just after soldering, it's also worth to use some flux for soldering.