Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=3 Fuz1=3 Fuz2=3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v1EN68HZ031113 for ; Wed, 15 Feb 2017 00:06:09 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cdm71-0002uC-4e for rs_out_1@blacksheep.org; Tue, 14 Feb 2017 23:02:19 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cdm70-0002u3-S3 for rsgb_lf_group@blacksheep.org; Tue, 14 Feb 2017 23:02:18 +0000 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1cdm6x-0005ZW-E6 for rsgb_lf_group@blacksheep.org; Tue, 14 Feb 2017 23:02:17 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id EFA9B20CF9 for ; Wed, 15 Feb 2017 00:02:14 +0100 (CET) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3vNHxL54Fpz1041 for ; Wed, 15 Feb 2017 00:02:14 +0100 (CET) Message-ID: <58A38C76.9060406@posteo.de> Date: Wed, 15 Feb 2017 00:02:14 +0100 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: In-Reply-To: X-Scan-Signature: 195b836cb7437e99aa05107459888659 Subject: Re: LF: Raspberry Pi sound interface that works Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.75 Status: RO X-Status: X-Keywords: X-UID: 10594 Very interesting! 6 synchronous sampled inputs, that's the perfect system for the tree. I can imagine the power consumption is even lower than my 2 stereo USB soundcards. 2 loops + 1x E field + PPS+NMEA, i.e. 4 channels for VLF, the perfect system. And 2 left for MF... Tell me when this board with 6 inputs is available please :-) 73, Stefan Am 14.02.2017 16:52, schrieb Paul Nicholson: > > USB audio on the Raspberry Pi is pretty useless thanks to > lost USB packets. A much better solution for audio is to > use the I2S bus via add-on boards such as the Wolfson. > > Unfortunately the Wolfson never worked with the quad core RPi. > I'm just testing another one, called an Audio Injector from > Flatmax Studios. It uses the same wm8731 chip as the Wolfson > but works with the quad core Pi: > > http://audioinjector.net/ > https://www.amazon.co.uk/gp/product/B01HBC8CJ0/ > > Runs up to 96k samples/sec stereo in full duplex. > > Measured input performance is at > > http://abelian.org/scard > > (Ignore the two spikes in the noise floor, these are from > the neighbour's solar panel. I'll measure the noise again > after sunset!) > > Noise is lower than 1uV in 1Hz and full scale input is > quite high, so the dynamic range is great. It runs at > 32 bits per sample very nicely. > > It appears to run real well with ebsynth: > > http://abelian.org/vlf/tmp/170214b.gif > > Uses about 11% of one core and appears as good if not better > than even a PCI soundcard on a PC! > > It looks like Flatmax Studios are kick starting development > of a multi-channel version with 8 outputs and 6 inputs. If > that works it will be great for 3 axis coherent reception > with just one Raspberry Pi. Due apparently in April. > > A lot more testing to do but so far it looks promising. > Sorry I just bought the last two from Amazon uk so they're > out of stock for the moment! > -- > Paul Nicholson > -- > >