Teensy 4.0 and EEPROM.h problem

[PaulStoffregen]

I still do wonder how to write and read a specific EEPROM position without the library

If you read EEPROM.h, you'll see it just calls core library functions like eeprom_read_byte(), eeprom_write_block(), etc. These functions are the eeprom API defined by AVR libc, since Teensy supports compatibility with both Arduino EEPROM library and AVR libc functions. You can find those functions in the core library code if you really want to learn how it all works. Along the way, you can also take notice of which open source license applies for each file from the comments at the beginning. When reading the core library, pay attention to the folder name, so you read the code in "teensy4" rather than "teensy3". It's all there in source code, if you really want to learn how it works internally.

 

[Garug]

Thanks, I likely will look into it a bit later. It just takes some effort to dig that deep, I hope that at the end of the tunnel there is few simple not abstracted commands to put a byte in EEPROM and read it from there. That is essentially what I am doing now EEPROM.read and .write but trough so many layers of confusion (and maybe some needed functionality I do not realise yet.).