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From: Richard Miller <9fans@hamnavoe.com>
To: 9fans@9fans.net
Subject: Re: [9fans] Pi updates
Date: Tue, 29 Dec 2015 10:55:30 +0000	[thread overview]
Message-ID: <bb38a5f71217f84cb29b01eb6ceede4c@hamnavoe.com> (raw)
In-Reply-To: <1211924935.3518360.1451362224733.JavaMail.yahoo@mail.yahoo.com>

Thanks, Brian - that all looks very useful to make the pi more amenable
to hardware tinkering.

One small suggested amendment: your spiclock() says this -

/*
 * According the Broadcom docs, the divisor has to
 * be a power of 2.  This code rounds up so that the
 * resulting clock is the highest value no greater than
 * what's requested.
 */

but http://raspberrypi.org/documentation/hardware/raspberrypi/spi/README.md
has an erratum suggesting "power of 2" should be "multiple of 2".  I have
been using a default divisor of 250 for a 1MHz clock, and that's the frequency
I see on my oscilloscope.




  parent reply	other threads:[~2015-12-29 10:55 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1211924935.3518360.1451362224733.JavaMail.yahoo.ref@mail.yahoo.com>
2015-12-29  4:10 ` Brian L. Stuart
2015-12-29  4:52   ` Anthony Sorace
2015-12-29  6:29   ` Skip Tavakkolian
2015-12-29 10:55   ` Richard Miller [this message]
2015-12-30 21:55   ` Skip Tavakkolian
     [not found] <1247329197.3731220.1451419922659.JavaMail.yahoo.ref@mail.yahoo.com>
2015-12-29 20:12 ` Brian L. Stuart
     [not found] <546388050.3796592.1451425715223.JavaMail.yahoo.ref@mail.yahoo.com>
2015-12-29 21:48 ` Brian L. Stuart
     [not found] <170083162.3836274.1451437972190.JavaMail.yahoo.ref@mail.yahoo.com>
2015-12-30  1:12 ` Brian L. Stuart
     [not found] <1780889748.4171096.1451514147540.JavaMail.yahoo.ref@mail.yahoo.com>
2015-12-30 22:22 ` Brian L. Stuart
2015-12-31 16:25   ` Joseph Stewart
2016-01-02  3:26   ` erik quanstrom
     [not found] <594280736.4698467.1451711534944.JavaMail.yahoo.ref@mail.yahoo.com>
2016-01-02  5:12 ` Brian L. Stuart
2016-01-02 18:06   ` erik quanstrom
2016-01-02 19:58     ` Bakul Shah

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