What about using another micro to provide the clock?

 

What about using another micro to provide the clock?

Has worked well for me. I have programmed a few function generators. All square waves in my case, then I have used op amps and capacitors to shape the waveform to my bidding. I'm saving up for a GOOD scope so I can see them waves.

 

Why are you trying to get the maximum frequency out of the ‘555? A lower frequency should be easier to get it to work. Bipolar ‘555s cannot get anywhere near 2MHz. Is yours a CMOS one?

Bob