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Drive frequency and command rate question

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Last seen: 1 year 2 weeks ago
Joined: 2022-10-10 19:16
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Drive frequency and command rate question

I've designed and built an ESC based on the F405 and separately the F407 (same clock chip), and was wondering what was needed to increase the maximum drive frequency into the 30-36kHz range. The ESC works beautifully for some applications like motors with lower pole count, but I have an application that requires a faster drive frequency of at least 30-32kHz. Right now, if I put the frequency too high, it looks liek the CWT is tripping. 

From what I've seen, driving a single motor, the max at the moment is only 28kHz. I'm currently only using the serial input, CAN to pass commands to a second ESC (not necessary - just playing with it...), but everything else (periphery) is not used, including the temp sensor. I've run different ESCs at 32kHz on a 72MHz chip in the past, so my presumption is that it should be able to do it with the 168MHz chip. 

I'm hoping that this is not a monumental task, but if there's a way to do this, I'd appreciate some insight. Or is this a limitation of the RTOS? 

Also - what is the maximum serial command rate for the ESC? Can it process serial commands at 20Hz or better?