Bug 1133

Summary: Time scale incorrect when using non-zero pretrigger capture ratio
Product: libsigrok Reporter: minenofmeer
Component: Driver: fx2lafwAssignee: Nobody <nobody>
Status: CONFIRMED ---    
Severity: normal CC: soeren, uwe, w.lunenburg
Priority: Normal    
Version: unreleased development snapshot   
Target Milestone: ---   
Hardware: All   
OS: All   
Attachments: 1% pre-capture
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1% pre-capture
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Description minenofmeer 2018-03-07 16:34:45 CET

First of all: thank you very much for developing and sharing this really great tool.

I just compiled from source on a raspberry pi 3. 
I am using a Chinese USBEE clone (fx2lafw driver) to debug i2c communication.
When pre-trigger-capture-ratio is unequal to zero the time scale in the output of pulseview is not correct (factor 2 to small, time readings are to small, frequencies to high) for digital inputs. When pre-trigger-capture-ratio is set to zero the data are correctly displayed.
The analog input is always displayed correctly.

I did the same tests on a x86 linux machine, with also a recently compiled version of sigrok/pulseview. The outcome was the same: faulty display of digital signals when pre-trigger-capture-ratio is set unequal to zero.

PulseView 0.5.0-git-7b7ab1f

0.6.0-git-187c300b/4:0:0 (rt: 0.6.0-git-187c300b/4:0:0)
- glib
2.54.3 (rt: 2.54.3/5403:3)
- libzip
- libserialport
0.1.1/1:0:1 (rt: 0.1.1/1:0:1)
- libusb-1.0
- libftdi
- Host
armv7l-unknown-linux-gnueabihf, little-endian
- SCPI backends
TCP, RPC, serial, USBTMC
0.6.0-git-fb1870b/4:0:0 (rt: 0.6.0-git-fb1870b/4:0:0)
- glib
2.54.3 (rt: 2.54.3/5403:3)
- Python
3.6.4+ / 0x30604f0 (API 1013, ABI 3)
- Host
armv7l-unknown-linux-gnueabihf, little-endian
Comment 1 Soeren Apel 2018-03-07 16:43:24 CET
Hello, can you please show us some screenshots?
Comment 2 minenofmeer 2018-03-07 17:25:15 CET
Created attachment 393 [details]
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Comment 3 minenofmeer 2018-03-07 17:26:03 CET
Created attachment 394 [details]
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Comment 4 minenofmeer 2018-03-07 17:35:32 CET
Created attachment 395 [details]
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Comment 5 minenofmeer 2018-03-07 17:36:52 CET
Created attachment 396 [details]
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Comment 6 Soeren Apel 2018-03-07 17:46:05 CET
Thanks for the files. The fact that the analog output is correct in both cases tells me that this is a driver issue, not a PV issue. I'm reassigning the bug.
Comment 7 Uwe Hermann 2018-06-15 11:50:42 CEST
*** Bug 1233 has been marked as a duplicate of this bug. ***