[PATCH 5/8] staging: comedi: adv_pci1710: fix pci1720 bipolar data writes
Hartley Sweeten
HartleyS at visionengravers.com
Mon Jun 23 17:08:19 UTC 2014
On Monday, June 23, 2014 4:57 AM, Ian Abbott wrote:
> On 2014-06-20 20:01, H Hartley Sweeten wrote:
>> On the PCI-1720 board, bipolar analog output ranges use two's
>> complement data. Use comedi_offset_munge() to munge the comedi
>> offset binary values before writing them to the hardware.
>
> Which manual are you looking at? According to Table 4.7 in the
> PCI-1720U manual from Advantech, this should not be done as 0
> corresponds to -Vref output, 0x800 corresponds to 0V output, and 0xFFF
> corresponds to +Vref output, which is what Comedi expects.
Ugh.. My bad. I misread the tables.
Greg,
Please drop this patch.
Thanks,
Hartley
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