The Freedom-K64F is an ultra-low-cost development platform for Kinetis K64, K63, and K24 MCUs.

PTC12 isn't a PWM output

28 Jan 2017

PTC12 doesn't support PWM output (or at least doesn't function using the mbed libraries).

The pinout image above should be updated to reflect this.

Maybe the green LED should also be shifted pins. It shares a pin with the one exposed on the headers (PTE26) and thus causes problems when that pin is then configured as an input.