#garfield Logs

Jan 06 2021

12:00 AM rue_mohr: yay I'm digital fitlering!
12:07 AM rue_mohr: zippo:/files/programming/c/FIR/test1# ./a.out
12:07 AM rue_mohr: Freq: 100.000000, Vop-p: 1.739873
12:07 AM rue_mohr: 2Vp-p in
01:11 AM rue_mohr: huh, it rolls off just as it hits nyquest
01:54 AM rue_mohr: a quick read seems to imply that you can use FFT logic to build FIR constants
01:54 AM rue_mohr: interesting
01:57 AM rue_bed2: bleck, Its annoying having to do a bunch of self educating to play with neat things
01:57 AM rue_bed2: the reason I wanted to play with FIR is from what I saw when I was playing with FFT
01:58 AM rue_bed2: the difference, so I said, was that one of the systems gets its constants from a sine wave and the other from an array of arbitrary constants
01:58 AM rue_bed2: but the FFT does the math in a horrid order
02:01 AM rue_bed2: I wonder how I can get a book organized of my circuits
02:02 AM rue_bed2: without doing a crazy amount of work
07:09 AM polprog: ohh fir filters
07:09 AM polprog: i tried to write one once
07:10 AM polprog: http://polprog.net/papiery/filters/fir.c
08:19 AM rue_mohr: hmm
08:24 AM aandrew: attn rue_mohr https://www.instructables.com/Building-Giant-Articulated-Hands-carved-From-Wood-
08:37 AM Tom_L: i bet those are heavy even just to hold up
08:39 AM aandrew: I've written FIR filters, even nice ARM NEON+ optimized stuff. the magic is not in the algorithm at all, but in the coefficient calculation
08:39 AM aandrew: there are some nice calculators where you specify taps and desired rolloff and it'll spit out the coefficients
10:56 PM rue_mohr: yea I found a second one last night
10:57 PM rue_mohr: interseting find, as I been working with hands
10:57 PM rue_mohr: its the big thing guy, I think