public inbox for linux-iio@vger.kernel.org
 help / color / mirror / Atom feed
From: Xander Huff <xander.huff@ni.com>
To: lars@metafoo.de
Cc: Jaeden Amero <jaeden.amero@ni.com>,
	Josh Cartwright <joshc@ni.com>,
	Joseph Hershberger <joseph.hershberger@ni.com>,
	linux-iio@vger.kernel.org
Subject: XADC values read from VAUX0-15 are consistently ~10% less than they should be
Date: Tue, 05 May 2015 17:11:38 -0500	[thread overview]
Message-ID: <5549401A.4080800@ni.com> (raw)

Hi Lars,

I've been working on transitioning one of our hardware devices over from using 
the out-of-tree hwmon driver that Xilinx used to provide to the xadc driver you 
added upstream, but I've been having trouble accessing our connected auxiliary 
channels. I've found that for all channels I've tested, after multiplying the 
raw value by the scale value (0.244140625), the resulting mVs are always about 
10 percent less than what we expect them to be. (2.9V instead of 3.3V, 5.4V 
instead of 6V, etc.). I'm interested in any tips you may have on how to debug 
this issue.

Thanks!

--
Xander Huff
Staff Software Engineer
National Instruments

             reply	other threads:[~2015-05-05 22:11 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-05 22:11 Xander Huff [this message]
2015-05-06 18:35 ` XADC values read from VAUX0-15 are consistently ~10% less than they should be Xander Huff

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5549401A.4080800@ni.com \
    --to=xander.huff@ni.com \
    --cc=jaeden.amero@ni.com \
    --cc=joseph.hershberger@ni.com \
    --cc=joshc@ni.com \
    --cc=lars@metafoo.de \
    --cc=linux-iio@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox