[sdiy] STM32 (or other) audio DSP learning recommendations

[Eric Brombaugh]

On 07/05/2018 07:33 AM, Martin Klang wrote:
> 
> The H7 is fun. It's a shame the HAL is so terrible. I know, it's better 
> to roll your own, but it's a complex device and just reading the 
> reference manual is a job in itself!

HAL isn't -awful- if you use it carefully. I tend to use it just for 
initial setup and then do direct register access for the realtime 
control. HAL provides a nice complement of lightweight inline macros for 
most bitbanging you might need to do so it still ends up looking fairly 
coherent even when you're bypassing most of the heavy functions.

>  From my experiments the F7 only gives a moderate performance boost, 
> while consuming almost twice as much power. Not ideal.

For the applications I do the F7 running full-bore is about 2-3x faster 
than an F4 - mostly due to the caching, but you're right that it's 
power-hungry. In some applications I actually dial the clock frequency 
back a fair bit until my application just barely meets its schedule 
deadlines just to save the milliamps. There's another penalty to pay - 
the cache can do strange and hard to debug things. Be aware of it, 
especially when you're working with DMA.

Eric