I have just added the ESP32 toolchain to the Arduino IDE (v1.8.0) on Windows 10. To get the IDE to allow me to select ESP32 chips I had to place the Espressif folder in "D:\Program Files(x86)\Arduino\hardware" (Yes my C drive is called D, its a long story)
I managed to compile and run Blink and after several minutes of celebration I tried the ESP32 Example Wifi->WifiScan. It failed to compile because
WARNING: Category '' in library OneWire is not valid. Setting to 'Uncategorized' In file included from D:\Program Files (x86)\Arduino\libraries\WiFi\src\utility\spi_drv.cpp:21:0: D:\Program Files (x86)\Arduino\libraries\SPI/SPI.h:16:26: fatal error: avr/pgmspace.h: No such file or directory compilation terminated. Multiple libraries were found for "WiFi.h" Used: D:\Program Files (x86)\Arduino\libraries\WiFi Not used: D:\Program Files (x86)\Arduino\hardware\espressif\ESP32\libraries\WiFi Multiple libraries were found for "SPI.h" Used: D:\Program Files (x86)\Arduino\libraries\SPI Not used: D:\Program Files (x86)\Arduino\hardware\espressif\ESP32\libraries\SPI exit status 1 Error compiling for board ESP32 Dev Module.
If I am reading this correctly, there are a couple of duplicate libraries, Arduino versions and ESP32 versions and the IDE picked the Arduino versions.
Is there a way of telling the IDE to prefer the ESP32 libraries rather than Arduino ones? I suspect all I need to do is change the order of the -I and -L commands, but I don't have a clue how, or if that's the right thing to do.