MOSFET LED strip switching - with 3.3V control, using 555 timer PUBLIC

WIP on using a 555 timer IC to drive an IRF540 MOSFET for 12V LED strip PWM without needing the microcontroller to supply fast PWM. INCOMPLETE.

Continuing on from this IRF540 driver circuit, replace the totem pole and npn/pnp push/pull with a 555.

The 555 has active push/pull on its output pin and can easily deliver 100kHz for fast LED PWM.

Incomplete. The 555 is in free-running astable mode right now and very slow. The next step is to have the microcontroller input use the reset to turn the timer off, and the control pin voltage to vary PWM rate.

I'm having a problem with the 555 always delivering a 5V OUT - see this forum post which I think might be related to the simulation. So I haven't added the microcontroller input yet.

All following on from this stackexchange question.