In the online documentation of the ESP32 I found a warning concerning the use of the SPI interface as slave: Warning: Due to a design peculiarity in the ESP32, if the amount of bytes sent by the master or the length of the transmission queues in the slave driver, in bytes, is not both larger than ei...

Since compilation in windows was too slow I also installed the Windows Subsystem for Linux (WSL). This works really fast. Thank you for the hint so far. But I am having a problem: when I invoke the terminal via "make monitor" I can not exit the terminal using the key "Ctrl+]". How can I accomplish t...

nice answer from ESP_Angus - but why there is no https_mbedtls server example? If mbedtls is the library to prefer I would expect that there are more and better examples...

thank you for your fast answer.
yes, I will be using FAT filesystem with the in esp-idf provided C library. The webpages of course will only be read; so, a simultaneous read of the same file from two different tasks needs to be possible. I guess your answer gives green light for this approach, right?

I am trying to implement a webserver which serves the webpages stored on an SD card. It also should be able to serve more than one simultaneous connection. For this the esp-idf driver for the SD card needs to be reentrant. Is this the case?

Now I saw that there is a bt_spp_acceptor and bt_spp_initiator example available. This seems to be the "missing" BT-classic SPP profile. Has anybody tested it?

My current SW compiles o.k. but during startup of the µC I receive strange messages (in yellow): 0x40080000: _WindowOverflow4 at E:/msys32/opt/esp/esp-idf/components/freertos/xtensa_vectors.S:1685 and 0x400d0018: _flash_cache_start at ??:? and 0x4008bfa4: bb_init at ??:? Do I need to worry about the...

now I fixed my problem: it was related to a race condition between incoming and outgoing telegrams. Now btStack works. Unfortunately even after tuning everything the the BT communication is much slower than the direct serial communication (approx. factor 2).
@loboris: Thanks for your support.

now I also changed hci_dump.c and now there is no logging any more. But my problem remains the same: the communication is too slow. Can you check how fast you can exchange data?

using esp_log_level_set("[BT_STACK]", 3); you can only switch off logging of the esp-idf functions. The btstack still logs many data: I (114548) PacketHandler: spp_send_packet() D (114549) SendPacket: begin [00:01:54.549] ACL => 80 00 19 00 15 00 41 00 09 EF 20 00 41 02 30 30 30 31 32 3 0 35 36 2E 3...