ESP32 wifi transparent bridge

[electronichamster]

Hello,
I'd like to use ESP32's wifi and BLE capabilities for a transparent uart bridge. I have a microcontroller that I'd like to interface with the outside world via the UART. I have a BLE module that's acting as a BLE-UART bridge talking to a phone app. But there are some things that I'd like to do via wifi because of the limitations of BLE, but I'd still like to maintain the current BLE implementation. Currently, JSON data is passed via BLE to my application MCU (we're using JSON for a reason), and my application MCU passes JSON response back to he BLE module to relay to the phone app.

1) BLE-UART bridge:
The BLE-UART bridge would function like the Nordic definition for a BLE-UART bridge. GATT server advertises two characteristics - a writable one for TX and a readable/notify characteristic for RX. In this case, you're limited the the number of bytes for GATT characteristic payloads. My application MCU takes care of packetizing long JSON strings, and the MCU and Android pieces JSONs together.

2) WIFI-direct UART bridge:
Looking to be able to stream TX and RX data between an Android/iOS phone and the ESP32. Unlike BLE where the protocol is fairly well defined, I don't have a good idea of how to do this part, so any insights here would be useful. I'm trying establish feasibility and get some terms that I can google and talk to the mobile app developer. I'm working on the firmware side. And I'm guessing wifi direct, but maybe that just ends up being the ESP32 acting in AP mode to allow for connections, and then somehow stream bi-directional data - somehow.

So on the ESP32 side, I want to do wifi direct and BLE concurrently. I'd like some advice on feasibility, and maybe suggestions for implementing the wifi uart bridge. I actually saw someone else ask about the UART bridge functionality. I think it's super useful.