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PSoC 5, 3 & 1

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Hi all


I am relatively new to programming, and just discovered the PSOC line. Let me say...these IC's look awesome! I have quite a few applications that I have been playing around with in my head for quite some time, and the PSOC line seems like a perfect fit! 




Anyways, I have just ordered an evaluation board, and am now reading through the documentation of each block. Is it possible to adjust the filter cutoff frequency in real time? I am working on an audio application (compressor) and would like to have variable 2nd order butterworth high and low pass filters in the sidechain. Would this be possible? I have read the documentation and do not see anything implying that it can be adjusted in real time, but may have missed something. If the filter cuttoff cannot be adjusted in real time, what are the work arounds? I would REALLY like to use these IC's as an all-in-one solution. 😄



2 Replies
Expert II

Welcome in the forum and in the fascinating world of PSoCs!


Short answer: Yes, you can.


Long version: The Filter component has got 128 bytes of ram area to store filter coefficients which you may change under program control.


Very long version: The filter block is a programmable DSP. There is an assembler you may use to construct your own algorithms for filtering.


But;  I can assure you that this is nothing for the newbies, it is complicated as .... (language barrier involved).


I would suggest you to:


Download and install (complete) PSoC Creator. This will give you access to all the documentation and a heap of example projects.


Installing the Kit-Only files for your evaluation board. So you will get some board-specific examples additionally.


Programming will be done in C-language, so get hands on a manual like this one.




Happy coding




Nathan, I suggest doing a Google (or other) search for The Filter Wizard who is Kendall Castor-Perry. He has a blog on Cypress for all things about filters -- FIR, IIR, time aligning multiplexed inputs. You will find a fantastic filter education with him. The short answer to your question is YES you can do the cutoff in real time -- even with multiple input channels at audio frequencies. You can also do a search for The Filter Wizard in this Cypress Community window.