I think this is the problem: return *(uint8_t*) t.rx_data; You need to set rx buffer and ther return that buffer address: uint8_t data; t.rx = &data; return data; // or return &data; // watever suits you Or issue may be here: void RC522_cmd(spi_device_handle_t spi, uint8_t cmd) { esp_err_t ret; spi_...

1) I dont know if it is possible to organize project the way you pictured, but you can have many workspaces. You can create workspace BASE and in it you can create every single project which you need 2) Very easy. It does not matter where do you have your project in file system. For example, you can...

This is not exactly answer on you question, but i think you may be interested. ESP32 has deep sleep mode and can be wake up by signal on gpio and ready to work faster than you need. http://esp-idf.readthedocs.io/en/v2.1/api-reference/system/deep_sleep.html?highlight=deep%20sleep http://esp-idf.readt...

Im having similar symptoms from time to time. Im playing with esp on vbox ubuntu 14, and only unplug device and plug again helps. Sometimes this does not help then i have to turn on manually bootloader mode under windows and then switch to ubuntu and flash app. In my case it is with devKitC rev1 i g...

Maybe it not covers all topics you want but its more just than simple example:
https://github.com/nkolban/ESP32_Explorer

I think it may be good start for you https://leanpub.com/kolban-ESP32

What offset parameters have you setup in flash downloader for each bin file?

Unlucky it is that arduino is delivering library WiFi and another WiFi library is delivered with BLE stack created by Neil Kolban. If you dont plan to use BLE stack from Kolban then you can delete it from hardware/espressif/esp32/libraries/. Im not guarantee it will solve this issue but its my best ...

Most likely its becuse you didnt use --recursive flag when you git cloned and didnt update submodule. You are missing few submodules.

This may be not good idea, but did you think about freeRTOS notifications? It has less footprint in ram usage. Let say you have task which is blocked until button is pushed. That task can keep pointers to all tasks you want to receive message about this event. Now, when button is pushed you can send...