Return-Path: X-Spam-DCC: paranoid 1233; Body=3 Fuz1=3 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u1HFb9GK015422 for ; Wed, 17 Feb 2016 16:37:10 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aW45H-0001n1-92 for rs_out_1@blacksheep.org; Wed, 17 Feb 2016 15:32:07 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aW45G-0001ms-Ty for rsgb_lf_group@blacksheep.org; Wed, 17 Feb 2016 15:32:06 +0000 Received: from mail-wm0-f54.google.com ([74.125.82.54]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1aW44O-00035F-7q for rsgb_lf_group@blacksheep.org; Wed, 17 Feb 2016 15:32:05 +0000 Received: by mail-wm0-f54.google.com with SMTP id g62so33389206wme.0 for ; Wed, 17 Feb 2016 07:30:59 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=sJ+ym3c/Jw3AbtMNfdTt685qYFGXNO1UbiymzWpYurI=; b=MOE6ObsFvKBB2I9I2c/CzzXdpxFv9KU5+mrHSDTWMBgc4zGO4IzcniHfysUlfDtDR+ 6cHR0DyU9CQvPR3ViEADR9CgwmEs+cxjv/0MN9i6nyBMkVXjkPXCmW6L+fMYrcHbUf31 JWZghmXDhotumGk0Kkl74nSQkIjyEhsWS5t6dBodxh2r3AI4Ww/U7qQZYtS8sThA3IUE rgZtZ8l4f1nSGrcEEZlzVs8AbufRQs49RoL2z9Nbx64Gp864rbqPIJYDeQC4Sl1Fnt0P B5cD9/iHFV+YEKNb6TbnpPEVsoX+K+vdLKDl/QKcDBusnN4BdDW3c8Ys/Io3Br2A1DQg nCHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=sJ+ym3c/Jw3AbtMNfdTt685qYFGXNO1UbiymzWpYurI=; b=Ef5Kvw9PxW20MjdpCTIip+c4F8gHAvgSBV6pMriMbZEpDNa2vGdrBZfe80t5IhTPwF jUQGwTNo4Zmu4ov+yHxBgy4crbd2kgIyuh/IE65rqbIubJewxMTdSWU88QjVKuwvnFcc VRLGrOSEqtUq9zsJ2iOAM2zGmCXTSuLuyEkUDxhJDhtaWHQ2jbl1ppaKeX2zm2LibYpZ ST8qoucNyfUFTpwZbAqU/RhlonqnB2sF/1KEtUblzQbPjY0VMwm8mdFDtqQJ6mRPqyCG 55UbhqjDzGh0MBlMzjNOxeGspo9Txtm9ug7hWQc7V75rFThsCB44jDVPMP7MeWd6ONgD 2h5A== X-Gm-Message-State: AG10YOQgLDBGulscwyxjJNRobyb3e2Tgi6XR6m//BhisbYS9FaHpKmXMQGsJgbgakmgN+QsXGllbDn6O5jwFGg== MIME-Version: 1.0 X-Received: by 10.194.142.135 with SMTP id rw7mr2641832wjb.42.1455723013649; Wed, 17 Feb 2016 07:30:13 -0800 (PST) Received: by 10.28.187.213 with HTTP; Wed, 17 Feb 2016 07:30:13 -0800 (PST) In-Reply-To: References: <56BDED97.5060308@freenet.de> <56BE0364.6070503@gmx.net> <56BE1134.7060205@freenet.de> <56BE1D9E.6060200@freenet.de> Date: Wed, 17 Feb 2016 15:30:13 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org, rsgb_lf_group@yahoogroups.co.uk X-Scan-Signature: d0d76c369792b807e0925732d18ad9b1 Subject: Re: LF: PIC-based GPSDO with A/D converter / supported serial baudrates ? Content-Type: multipart/alternative; boundary=089e013a1de01ebfdd052bf8ed01 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 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 6862 --089e013a1de01ebfdd052bf8ed01 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hit send too soon ................ mutter, mumble........ The following results were obtained : Requested Frequency Baud rate Generated 3M 146xxx (it wobbled) 2M 975xxx (it varied) 1M 500000 800k 400000 500k 250000 480k 240000 So it looks as if the FTDI Chip's FT232 family is eminently useable to 1M baud With a 12 bit A/D and some framing, for two bytes per sample, that means you could send 0.5M Samples/ second 16 bit sampling plus framing will need three bytes, so call it 300kS/s Andy G4JNT On 17 February 2016 at 15:23, Andy Talbot wrote: > I've just made some tests on the FTDI232 chip at high baud rates. > > Using a custom routine written in PowerBasic (CC) , I used that > language's own interpretation and interface to the driver to pass arbitra= ry > baud rates to the chip. With the device set for 8 data, 1 stop bit and > no parity, I repeatedly send the character 0x55 in a continuous loop. Th= is > pattern of bits, if sent contiguously (characters are sent LSB first) > should therefore result in a square wave being generated at a frequency > exactly equal to half the specified baud rate. > > The FTDI232 data sheet states that baud rates are determined based on a > 3MHz input to a divisor of (N + M/8, where N =3D 2 to 16384, plus two spe= cial > cases on N =3D 0 and N =3D 1 for 3Meg and 1Meg rates respectively. Thi= s > setting is hidden from my application, and happens transparently based on > the baud rate I specify beign passed to the driver via PowerBasic. > > The following results were obtained : > > Requested Frequency > Baud rate Generated > > 1M 500000 > 2M > > > > On 12 February 2016 at 17:59, Wolfgang B=C3=BCscher w= rote: > >> Thanks Andy. I wanted to keep it simple (but not necessarily stupid), by >> using available hardware. In my case, the dreadful (and, most likely, >> "faked") Prolific USB <-> RS232 adapter. >> >> > > --089e013a1de01ebfdd052bf8ed01 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Hit send too soon ................
mutter, = mumble........

The following results were obt= ained :

Requested=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0 Frequency
Baud rate=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Generated

3M= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 146xxx=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0 (it wobbled)
2M=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0 975xxx=C2=A0=C2=A0=C2=A0=C2=A0 (it varied)
1M=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 500000
800k= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0 400000
500k=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0 250000
480k=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0240000

So it looks as if the FTDI Chip's=C2=A0 FT232=C2= =A0family is=C2=A0eminently useable to 1M baud

Wi= th a 12 bit A/D and some framing, for two bytes per sample, that means you = could send=C2=A00.5M Samples/ =C2=A0second

16 bit = sampling plus framing will need three bytes, so call it 300kS/s
<= br>


Andy=C2=A0 G4JNT

=


On 17 February 2016 at 15:23, Andy Talbot <andy.g4jnt@= gmail.com> wrote:
= I've just made some tests on the FTDI232 chip=C2=A0at high baud rates.<= /div>

Using a custom routine=C2=A0written in=C2=A0=C2=A0= PowerBasic (CC) , I used that language's own interpretation and interfa= ce to the driver to pass arbitrary baud rates to the chip.=C2=A0=C2=A0 With= the device set for 8 data, =C2=A01 stop bit and no parity,=C2=A0I=C2=A0rep= eatedly send the character 0x55 in a continuous loop.=C2=A0 This pattern of= bits, if sent contiguously (characters are sent LSB first) =C2=A0should th= erefore result in a square wave being generated=C2=A0at a=C2=A0frequency ex= actly equal to=C2=A0half the specified baud rate.

= The FTDI232 data sheet states that baud rates are determined based on a 3MH= z input to a divisor of (N + M/8, where=C2=A0N =3D 2 to 16384, plus two spe= cial cases on N =3D 0 and N =3D 1 for=C2=A0 3Meg and 1Meg rates respectivel= y.=C2=A0=C2=A0 This setting is hidden from my application, and happens tran= sparently based on the baud rate I specify beign passed to the driver via P= owerBasic.=C2=A0

The following results were obtai= ned :

Requested=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0 Frequency
Baud rate=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Generated

1M=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 500000
2M



= On 12 February 2016 at 17:59, Wolfgang B=C3=BCscher <<= a href=3D"mailto:dl4yhf@freenet.de" target=3D"_blank">dl4yhf@freenet.de= > wrote:
=20 =20 =20
Thanks Andy. I wanted to keep it simple (but not necessarily stupid), by using available hardware. In my case, the dreadful (and, most likely, "faked") Prolific USB <-> RS232 adapter. =C2=A0=C2=A0=C2=A0


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