Well if you got as far as you did you have already installed the ESP32 boards so you can pick the correct one. I assume the core basic does still use the "M5Stack-Core-ESP32" board. https://github.com/m5stack/m5stack This link shows the documentation for the Grey(which I am using) and the Basic. I can't translate all the warnings you got but the last part seems to indicate it isn't pointing to the correct config.h(or it can't find it). Config.h, i believe, is the library that is handling defining all the pins used in the stack. So without it the board has no idea what is going on. Are you able to open other sample arduino sketches and select something like an UNO and compile just fine? I wish I could help more. The only thing I can suggest is to step through the setup once again. https://docs.m5stack.com/en/quick_start/m5core/arduino

@hwtaro9 yes, they are located on the M_Bus

What are you trying to do? There are loads of examples but if you are trying to build something specific that might help. I did a beginner 3.5hr video on doing a gps based speedo and talk about some basic graphics, text display and getting GPS using the TinyGPS++ library. not sure if that is what you are looking for. https://youtu.be/xlb7FGKBp3Q

@parahooner Very many thanks for posting this, it completely resolved the problem.

Look at the M5Unified Speaker example it has full volume and tone control and runs on the Core2

@hoodlem Hi! Thanks for the feedback! this is already on our lists! stay tuned for more

@glennswest Hi there, thanks for your feedback! we will be sure to let our innovation team know!

@glennswest Hi there! please have a look at https://docs.m5stack.com/en/unit/extio2 this supports software configuration of I2C address