Screen backlight brightness

[jLynx]

There is a transistor connected to the cathode for the screen controlled by the CPLD.
I see we have some code in backlight.cpp to control it, but I cant for the life of me get it to change, if I set it to 1 or 31(max brightness), its the same brightness.

Files of note:

• https://github.com/portapack-mayhem/mayhem-firmware/blob/42824e4aec331382c21b0cae67f49e5556448d89/firmware/common/backlight.cpp
• https://github.com/portapack-mayhem/mayhem-firmware/blob/42824e4aec331382c21b0cae67f49e5556448d89/firmware/common/backlight.hpp

   private:
    static constexpr value_t initial_brightness = 25;
    static constexpr value_t maximum_level = 31;

    static constexpr uint32_t ticks_setup = 204e6 * 10e-6;
    static constexpr uint32_t ms_pwrdwn = 5;
    static constexpr uint32_t ticks_lo = 204e6 * 1e-6;
    static constexpr uint32_t ticks_hi = 204e6 * 1e-6;

I am wondering if the ticks_lo & hi are incorrect since turning it on and off works with the button, but trying to control it with PWM doesnt seem to work. Could also be related to where we are calling set_level()