Like to share some usage experience here.
As most of you may know those OBD_wifi/Bt/USB acutally is a OBD-to-serial converter,
convert OBD data communication to serial (RS232) so easier to use and control in computer by COM-port.
With another serial UART converter, convert RS232 communicate to USB, BT and even Wifi.

It is china vLinkerMC Wifi now I’m using.
With using AT commands, find that the chip is MIC3312,
wifi module is HF-LPT230.
Both are develop and made in china.

About HF-LPT230, it is serial to Wifi 802.11b/g/n converter,
support STA, AP, and also AP+STA mode.
Normally it run in AP mode, and this is the mode we normally use.
If you want customize configuration, by using AT+ command, you can change SSID, wifi key password,
and also turn it run in STA+AP, so every devices can also have internet connect and OBD communication.
Its serial support upto 4Mbps, but in vLinker it is just running at 38.4kbps.

Brief about that MIC3313.
OBD proctocol support up to 500kbps !
It is good for ISO15765-4 which communicate with vehicle in full speed, in theory.
Serial baudrate 38.4kbps by default…
Problem start here, in theory the serial baudrate is programmable (use AT command),
but in MIC3313, it is either not changeable ? or not support due to not implemented in firmware.

It support all ELM327(v2.2) and STN11xx commands and VT commands.
ELM327, you may heard it for long, most OBD dongle are this kind, use AT commands.
STN11xx, the famous ODBLink is using this chip, it also support all as ELM327(v1.3). use AT and ST commands.
(VT commands, not much info about its background, but not important)
So in one chip it almost support everything we need.
Sounds good, but…

Searched around found MIC3313 offical site and contact.
Read over the datasheet, MIC3313 serial baudrate is programmable!
Wrote a email to offical support, but the respond is ridiculous.
They insist the serial link between chip and wifi module is 500kbps.
What the bs, they even don’t know their product !

Why that serial baudrate is so important,
you can refer to Vasilich’s post
https://torque-bhp.com/forums/?wpforumaction=viewtopic&t=16621.0

If you have something like to share or find any mistake,
welcome to talk here.