This post is not very popular. :'( I am still coming up empty handed. One thing that makes this issue extremely hard to debug, is that my application used up all of the GPIO pins on the ESP32. So I cannot connect a JTAG and use a debugger.

Doing some deeper digging, I found out that the rfcomm ...

A followup after digging through the Programming Guide for ideas. I basically want to try to not pull data from Bluedroid's queue, so that the queues fill up and Bluedroid might pause the sender automatically. For that, I don't want to read the data through the ESP_SPP_DATA_IND_EVT callback event ...

I forgot to say something important: I am developing in the Arduino environment with arduino-esp32 version 2.0.17 .

This is because I am using the FabGL library, which cannot run with the latest arduino-esp32 version 3.3.4 because that uses too much memory.

After some searching, it looks like that ...

I have made a device with on an ESP32 which has an RS232 serial port that's connected to a device (an old computer in this case). Serial connection with the old computer works great.

In the ESP32, I also offer a Bluetooth Serial (SPP) service, to which I can connect with a PC. In my ESP32, I then ...