From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 3437 invoked from network); 25 Apr 2021 17:57:55 -0000 Received: from 1ess.inri.net (216.126.196.35) by inbox.vuxu.org with ESMTPUTF8; 25 Apr 2021 17:57:55 -0000 Received: from mail-pg1-f180.google.com ([209.85.215.180]) by 1ess; Sun Apr 25 13:27:57 -0400 2021 Received: by mail-pg1-f180.google.com with SMTP id b17so1558294pgh.7 for <9front@9front.org>; Sun, 25 Apr 2021 10:27:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=g4fQr3T0KCP8jVJJzWYGbRwp2YLMRxYzAMbFQlaPfbM=; b=KtSVhxP40PZRO414eZo4LFtLPtu8vTd2Fv6VlzvM/Rcx9/Edjn2Zb9f7Xn5U4NOQ8u wtmjmqwcjar8Zg9R61abyfXX9spryG8NNdxQNQKZeW03eK8hL3MF2647AVBnrh9ZXf7P jKIYwJMmcSa4Rc/lacw0U3vUzRrU88zn5u/dMzIvrjghqRjCl3fXJFqIa+UQlMv8VF4L GFcV7QUJAP/D4G801hwZ40hmPaDqkrdhvYBpNaqfR7GcXkVy5HRxXJVebNP1NjgXE+j3 0E/uG3cFtAxLWlLzz2Xjt0HtP1F1cEiNR2Y2MnXDQb+jgBZF0XBJ94eP7WOps11Fx0yA hIDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=g4fQr3T0KCP8jVJJzWYGbRwp2YLMRxYzAMbFQlaPfbM=; b=cSrFVTDqNDbnqMG0+yWiiRquZvAOhOk/uJ2tZmYtHwRtBXddHAmRdI87LgOPMYXh6W QZA20OiDtMmjGM6i0u+cjcUZKeN1R3ExS3x7dzlDEDgn6VYxuW23c+DTbCkVmLJXv8XJ oR7q4oh8PG4rdl2/58vpPv6KO43FigY+D6PrdDLJmdkihPqjA4Lb2RcEYV7sUe6DvspE LqO0CzsFQpBy4TTQZZJupuSQSor2vKgpx/NO6tN1Y87nMeac811O+28XEFuW9/+5zGUZ V5au2qoQG1tBlJYForGpBfcCezFPMa2s9fhM1vhktBqq5D2Daju+6Np7OpGdxBLU4hgI SdWQ== X-Gm-Message-State: AOAM532Lg4TqsOlE32gLXx4JgyKmzDS5EUoXmYtBDvrl5XDCA+vXKevC zs4DBovCMB9rnL/aF63e1OdwY5QGUQiBcmxNdjx0+oLV X-Google-Smtp-Source: ABdhPJywAvY8e3q7H4xHwj943k/gQC526q2TGcyh3jU6UbiUrf8XhQPQG9bW1fs2sOkny0M1Ai5DQS4Y2213iYe/Tb4= X-Received: by 2002:aa7:80c9:0:b029:249:cac5:e368 with SMTP id a9-20020aa780c90000b0290249cac5e368mr13678283pfn.12.1619371290468; Sun, 25 Apr 2021 10:21:30 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a05:6a20:a01e:b029:1b:3549:26b7 with HTTP; Sun, 25 Apr 2021 10:21:30 -0700 (PDT) In-Reply-To: References: <0C73F8031AC040C9C98E26332A9A4D2B@felloff.net> From: hiro <23hiro@gmail.com> Date: Sun, 25 Apr 2021 19:21:30 +0200 Message-ID: To: 9front@9front.org Content-Type: text/plain; charset="UTF-8" List-ID: <9front.9front.org> List-Help: X-Glyph: ➈ X-Bullshit: browser-oriented cache event Subject: Re: [9front] Getting Started with Kernel Development? Reply-To: 9front@9front.org Precedence: bulk sorry, just realized this is rpi3. rpi3 has no good usb support, maybe that's why they thought gpio will be more stable? maybe you'll have to try it out, and if it doesn't work, just upgrade to a rpi4. On 4/25/21, hiro <23hiro@gmail.com> wrote: > here's a fitting solution > > https://de.aliexpress.com/item/1005002220730177.html > > i picked this one because it doesn't have a case, just like the rpi. > of course the ones with case are a little cheaper, but this way you > can say you built it yourself > > On 4/25/21, cinap_lenrek@felloff.net wrote: >>> I've also got the "BCM2835 ARM Peripherals" spec, which specifies how >>> to interact with the chip's I2S audio interface. >> >> As far as i know, the stock raspberry pi is not using I2S. >> >> There are some people that have build their own soundcards >> for the pi with a I2S DAC but it is not standard. >> >> Instead, they hacked together some filter circuit and connected >> it to a GPIO pin. >> >> (This pattern is a logical continuation on raspberry pi hardware >> design philosphy, where using the existing dedicated peripherals >> for their intended purpose must be rejected and standards must be >> ignored: cpu -> GPU, ethernet -> USB, audio -> GPIO, wifi -> SDCARD, >> usb -> ?????WHATISTHIS????, usbc -> ?????, PXE -> ???????). >> >> The GPU has firmware code to drive that GPIO pin and also send >> audio over HDMI, but todo that you have to talk to the videocore >> firmware thru a complicated software media streaming interface. >> >> Afik, it is possible to drive the gpio pin from the cpu somehow >> but quality will be garbage and waste alot of power. >> >> -- >> cinap >> >