Add chip_model method

[vickash]

I'm working on ESP32-S2 and ESP32-S3 support for mruby-esp32-gpio (PR soon). This method allows the mruby script to identify which chip it's running on.

[pandax381]

Thanks!

We will merge them, but there is one thing we would like you to change.
I would like the system type to be a constant value instead of a string.

[vickash]

Do you mean store the string in something like ESP32::Constants::CHIP_MODEL instead of a method? Or do you want to use the raw integers from the enum instead of a readable string?

[pandax381]

The later. I want the raw integers in enum to be defined as mruby constants and used as such.

[vickash]

Done. I'm working on the ESP-IDF 5.1 release btw. Lower versions won't have values for the newer chips available in the enum.

[pandax381]

Perfect!

I'll merge it once here.
Please submit another pull request for ESP-IDF 5.1 support.

[vickash]

5.1 generally works like 5.0 with no changes.

I meant that defining constants for new chips (introduced in 5.1) breaks backward compatibility with 5.0.

I changed it to be conditional based on IDF version in da5abb7. That should restore compatibility with 5.0.

[pandax381]

Thanks to this, I understand it.