Help identify this Module

[bitcom]

Hi everybody, I just got myself a solar inverter it is a SRNE Hyp model rebranded ECO WORTHY. Anyways if came with a wifi dongle to connect to internet for monitoring purposes but it was too slow and cumbersome to use.
So I decided to take it apart and find what microcontroller it was using (hoping for esp32) but to my bad luck, the label on the IC was erased so I've been unable to identify it, there is serial interface on it but noting is printed out I tried all boud rate from 9600-115200 aad nothing comes out.
The pins for tx/tx go to pins 27/28 on the IC.
Here are some pics of it, maybe somebody outhere has been on this road before and can point me on the right direction.
Thanks in advance...

[Psi]

Keep in mind the pin number doesnt always start in the same rotation from pin1 mark, so pin 27/28 could be pin 6/5

I checked a few common ones but didn't find anything that matched ANT and XTAL and UART.

[Sacodepatatas]

Hi everybody, I just got myself a solar inverter it is a SRNE Hyp model rebranded ECO WORTHY. Anyways if came with a wifi dongle to connect to internet for monitoring purposes but it was too slow and cumbersome to use.
So I decided to take it apart and find what microcontroller it was using (hoping for esp32) but to my bad luck, the label on the IC was erased so I've been unable to identify it, there is serial interface on it but noting is printed out I tried all boud rate from 9600-115200 aad nothing comes out.
The pins for tx/tx go to pins 27/28 on the IC.
Here are some pics of it, maybe somebody outhere has been on this road before and can point me on the right direction.
Thanks in advance...

The B02-02 marking on the silkscreen, suggests me that the MCU could be a Bufaloo Labs BL602/702...

[Whales]

Bufaloo Labs BL602/702...

Did an image search for "serial to wifi module Bufaloo" and found this



Very close.  Castellated pins are a bit different though (the OP's photo shows them unequally spaced around the edges).

[mikerj]

The B02-02 marking on the silkscreen, suggests me that the MCU could be a Bufaloo Labs BL602/702...

Very interesting parts, I hadn't heard of them.  Unfortunately the antenna pins don't match up to the OP's circuit; QFN32 BL602 is pin 9 and BL702 is pin 16 and the OP's looks to be pin 2.  The old ESP8266 has the antenna on pin 2, but pins 27,28 are for a crystal and 25,26 are UART.

[bitcom]

Thank you both for your observations, I also thought it is a Bufaloo Labs micro and downloaded their programming software but could not be identified, maybe because it needs to be put into boot mode first. Apart from the usual serial pins grd tx rx vcc, there are 2 more labeled srv and buz I tried connecting them to vcc 3.3 through a 10k resistor but nothing happened on the serial console. As far as the pinout I'm assuming pin one is the one closest to the crystal going CC. Thanks again

[mikerj]

I found this FB post (will need translating) that shows the same module: https://www.facebook.com/groups/535518005787356/posts/696153129723842/

The part number leads back to this manufacturer and they also have the four petal flower logo: https://www.eybond.com/page192?_l=en

Some useful information on specs, but nothing on the IC itself.  Something worth noting is it says the comms side is Modbus RTU (RS485). It's very late for me now so I'm off to bed, happy digging.

[bitcom]

Yes I found that Facebook post, did the translation and the guy was asking for someone to program it for him. This is a very common dongle used in a bunch of solar inverters, I would've thought someone had already flashed it with esphome which is what I wanna do make it a Bluetooth proxy for Home Assistant.