Bug 1010

Summary: Analogue and Digital channels not in exact sync
Product: libsigrok Reporter: skaggmaster
Component: Driver: fx2lafwAssignee: Nobody <nobody>
Status: UNCONFIRMED ---    
Severity: trivial CC: Gerhard.Sittig, soeren, uwe
Priority: Normal    
Version: unreleased development snapshot   
Target Milestone: ---   
Hardware: All   
OS: All   

Description skaggmaster 2017-08-10 17:37:53 CEST
Fiddling with my CWAV AX clone, I see that there is a lag of about 6 us between the analogue channel and the digital channels in PulseView. Analogue is behind. 
(Or around 4 samples at 500 kHz / around 2 samples at 200 kHz). Maybe a "user definable offset" can fix this.
Comment 1 Gerhard Sittig 2017-09-17 12:44:31 CEST
It's assumed that the skew is a property of the hardware in the capture device 
(very probably the ADC).  The software reflects the samples in the very way 
they are available from the FX2's perspective.

It's uncertain how generic an issue this is (applicable to _any_ mixed signal 
acquisition device? to arbitrary input files as well?).  I'd suggest to 
capture to disk, and optionally postprocess the analog part of the capture, 
before loading the file for subsequent inspection.  This might be as simple 
as dropping the first few bytes of the first/only analog chunk, and padding 
the last/only, to "shift" the analog trace by a desired amount of sample