Too confusing to do this myself, perhaps simple for you $$$?

You’ve probably had this sorted already, but the code for doing this is very simple, and you would probably be best just getting an Arduino and reading a few tutorials. It would be cheaper and once you’ve figured out the basics you’ll be able to quickly mess with frequency timing etc. Lots of sample code out there for setting up a timer on a pin.

Also watch the driving of the power transistors carefully. The micro can only really drive 20mA reliably, and if you are feeding directly into the gate, the transients current to charge the gate capacitance can be very high - enough to cause intermittent reliability problems.