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1. minute (mntmn@mastodon.social)'s status on Friday, 08-Dec-2023 23:24:00 JST minute

   who is good at texas instruments maths here and can tell me N0, N1 and D1 values for a lowpass? lets start with something extreme like 1KHz

   • minute (mntmn@mastodon.social)'s status on Friday, 08-Dec-2023 23:43:00 JST minute

     in reply to

     i asked google bard. i have some doubts

   • minute (mntmn@mastodon.social)'s status on Friday, 08-Dec-2023 23:48:16 JST minute

     in reply to

     • Timjan

     @timjan what would normalized mean in this case?

   • Timjan (timjan@social.linux.pizza)'s status on Friday, 08-Dec-2023 23:48:18 JST Timjan

     in reply to

     @mntmn
     I haven't touched these in a long while... Isn't z normalized sampling rate?

   • minute (mntmn@mastodon.social)'s status on Friday, 08-Dec-2023 23:57:09 JST minute

     in reply to

     • Timjan

     @timjan ahh i see, thanks

   • Timjan (timjan@social.linux.pizza)'s status on Friday, 08-Dec-2023 23:57:11 JST Timjan

     in reply to

     @mntmn
     z=1 would be the sampling frequency, z=0.1 is sampling frequency / 10.

     Saying "cutoff at 1kHz" doesn't help, because we don't know what the sampling rate is. If that is, say, 100kSamples/second, you'd want the cutoff at z = 1k/100k = 0.01.

     But again, I haven't done discrete filters since college, and over breakfast I might not be of much help 😬

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 00:34:44 JST minute

     in reply to

     • Arno DL2SSB

     @arnobert 48000Hz

   • Arno DL2SSB (arnobert@chaos.social)'s status on Saturday, 09-Dec-2023 00:34:46 JST Arno DL2SSB

     in reply to

     @mntmn Which sampling frequency do you use?

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 01:12:37 JST Dirk Eibach

     in reply to

     @mntmn are you planning to do a subwoofer out?

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 01:12:37 JST minute

     in reply to

     • Dirk Eibach

     @de i just want to test (hear) if the filter works at all (so far it doesn't do anything)

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 01:38:09 JST minute

     in reply to

     • Dirk Eibach

     @de haha, i also found this tool! but then we're on the same page. i'll try your results as well... my results don't do anything yet (just hardcoded in the driver)

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 01:38:10 JST Dirk Eibach

     in reply to

     @mntmn

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 01:38:10 JST Dirk Eibach

     in reply to

     @mntmn Where can I pick my prize😂 ?

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 01:38:45 JST minute

     in reply to

     • Dirk Eibach

     @de this is what i tried so far

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 01:48:41 JST Dirk Eibach

     in reply to

     @mntmn so you are texting on the audio input?

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 01:48:41 JST minute

     in reply to

     • Dirk Eibach

     @de yeah i want to try filtering some high frequency noise from the MIC input (ADC)

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:01:55 JST Dirk Eibach

     in reply to

     @mntmn this looks too simple

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:01:55 JST minute

     in reply to

     • Dirk Eibach

     @de you're probably right. Table 7-25. says "No" for first-order IIR. also my input is MIC1RP_P, not sure if that is routed to left mono channel or i need stereo processing

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:12:46 JST minute

     in reply to

     • Dirk Eibach

     @de hmm idk how that would work in parallel to the driver

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:12:47 JST Dirk Eibach

     in reply to

     @mntmn you said hardcoded in the driver. Can you access these via i2ctools?

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:18:34 JST Dirk Eibach

     in reply to

     @mntmn I don't assume that these values are written regularly. So it should work fine.

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:18:34 JST minute

     in reply to

     • Dirk Eibach

     @de i thought that i2cset doesn't want to write to claimed addresses, but probably i'm wrong?

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:20:34 JST Dirk Eibach

     in reply to

     @mntmn use the -f flag

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:20:34 JST minute

     in reply to

     • Dirk Eibach

     @de oh neat :3 thanks!

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:27:30 JST Dirk Eibach

     in reply to

     @mntmn 7.3.9.4.2.1 looks alright for your usecase

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:27:30 JST minute

     in reply to

     • Dirk Eibach

     @de yeah, so that's what i'm trying to use

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:38:00 JST minute

     in reply to

     • Dirk Eibach

     @de ahaaa! with ADC off, i can finally read some non-zeroes back from page 4

   • Dirk Eibach (de@noc.social)'s status on Saturday, 09-Dec-2023 02:38:01 JST Dirk Eibach

     in reply to

     @mntmn seems the ADC must be powered down for updating coefficients

   • minute (mntmn@mastodon.social)'s status on Saturday, 09-Dec-2023 02:38:57 JST minute

     in reply to

     • Dirk Eibach

     @de yessssss this was it, filter works! thanks a ton!