No chance to open the device without damage.
The plug - bought at Amazon, seems to be a bit different from the one described in #1:
The housing seems to be a bit different and so the chipset, but it's called "ANTELA Smart Plug Model: F1s202-EU", too (even on the housing bottom).
It seems that it really is a BK7231n, not BK7231t. Thoughts in my message #18 were wrong, it was a hw prob...
The config for the device changed, too.
Here's my complete setup:
1. Flash 3rd Party Firmware
2. From device-profiles (i.e. custom profile)
5. Put device in AP (slow blink) mode
6. Put device in AP (slow blink) mode again
P7 (PWM1) Btn 0
P8 (PWM2) Rel 0
P10 (RXD1) LED 0
P11 (TXD1) BL0937SEL
P24 (PWM4) BL0937CF1
P26 (PWM5) BL0937CF
It seems to be a bit difficult using the plugs with MQTT2 in FHEM:
There were some strange answers in the Current/Active Power/Apparent Power/Reactive Power/Power Factor/Energy Total section.
The "inf" and "nan" answers from the device aren't very helpful.
And: Which Flags should be enabled to get/set most of the possibilities of the plug under MQTT ?
Under Tasmota (Theo Arends) flashed devices aren't such probs...
Sorry, but flashing by wires isn't possible without bricking the device.
Initially nan is in: Current/Active Power/Apparent Power/Reactive Power/Power Factor/Energy Total, but i managed to get numbers in the responses. After applying values in Voltage, Current and Power i got reasonable values.
Think it could be helpful if the init value isn't nan, but 0?
The FHEM MQTT2 server is similar to Mosquitto, but a special one only for the FHEM home automation software.
You can find more of the meaning of FHEM in https://fhem.de/.
MQTT clients can automaticallly be configured by pre-built templates. I'm still working on such a template with some effort.
The Tasmota software built by Theo Arends has some different MQTT-names like "tele/sonoff/LWT" or similar.
Some of the device responses can be modified by parameters, that could be very helpful.
Another strange behaviour:
After a reboot of the plug the relay is always in the "off" state, regardless what i've done before.
Current value of the flags=1075840192.
What has to be done for remembering the switch state?
One additional general question:
Is it possible to switch the device in AP mode via button for reconfiguring it in a different WLAN environment?
In Tasmota you have to push and hold the button for approx. 40 seconds,