XADC values read from VAUX0-15 are consistently ~10% less than they should be
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!
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Xander Huff
Staff Software Engineer
National Instruments
Quoted 10 lines · Xander Huff
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.
Nevermind, it turns out I had somehow transcribed the scale value incorrectly for my testing. After modifying my test to directly use the scale values from our target, the resulting voltages came out as expected
Signature · 3 lines
Xander Huff Staff Software Engineer National Instruments