Cleanup boards.txt

[dbuezas]

The boards.txt file became unnecessarily big.
This PR reduces its size from 414 to 87 lines without losing features by:

• Removing all lines which were already commented out
• Removing dedicated boards for external clocks
• Adding 32, 16 and 12MHz external clocks to the clock source selection
• Changing the Clock menu to a generic Clock Divider menu that works with all clock sources and crystals.

Specifically, it:

• Removed Larduino Uno (same as the 328D variant)
• Removed LGT8F88D (was already commented out)
• Removed dedicated boards for 16 and 12 MHz external clocks (clock source & divider now independent)
• Removed 328D-SSOP20 (was already commented out)

[dbuezas]

@seisfeld @wollewald
Your feedback is also welcome :)
If I didn't miss anything, this would be released as v3.0.0

[LaZsolt]

I'll test the new menu after morning.
Does the divider menu look better this way?

1
1/2
1/4
1/8
1/16
1/32

[dbuezas]

It's also an option. We could use:

• divider (int or fraction)
• prescaler (int or fraction)
• multiplier (with fractions as you suggest)

I just thought that "divider" seems to be what we call it in issues

[dbuezas]

BTW, I tested it with an LQFP48 which has an external 16MHz xtal too, didn't see any issues.

[LaZsolt]

Prescaler.

[dbuezas]

(updated screenshot to Internal 32MHz)

[dbuezas]

This is how it looks with fractions

[dbuezas]

IMO the UI is much easier to understand and configure without the extra boards for each crystal. And the boards.txt is also way easier to follow

[wollewald]

Hi I just tried it. Looks better than before. And I would recommend to keep "clock divider" and not multiplier or prescaler. I think it's best understandable for beginners.
A pedantic comment: If you choose "Clock divider" and take the fraction style, e. g. 1/32, it's not correct. 32 is the divider and not 1/32. Then multiplier would be correct.

[dbuezas]

Release in progress