Opened 14 years ago

Closed 12 years ago

#2203 closed defect (fixed)

Measure 31 Rising/Falling Edge matches both rising and falling edge

Reported by: carrott Owned by: walter
Priority: Unspecified by Maintainer Milestone: Unspecified
Component: Measure Version: Unspecified
Severity: Unspecified Keywords: dextrose 11.3.0
Cc: Distribution/OS: Fedora
Bug Status: Unconfirmed


The rising and falling edge triggers trigger on both a rising and falling edge, making it difficult to get a stable waveform.

Wistleing gives you a nice clean sine wave and it would be great if the trigger worked and you could demonstrate the waves getting smaller and larger as you change your pitch. Without a working trigger, the wave dances around and it's difficult to see what's going on.

The best way to get a stable waveform is to put the trigger close to the top or bottom of the wave, so the distance between the rising and falling edge is small.

Change History (7)

comment:1 Changed 13 years ago by greenfeld

  • Keywords 11.2.0 added

Seen in OLPC 11.2.0 os14/Measure 32 using a sine-wave tone generator. We seem to be a bit too hair trigger sensitive and may falsely regularly trigger on the wrong side. It would be nice if the trigger level was adjustable, although it doesn't really need to be set to the top of the wave.

comment:2 Changed 13 years ago by carrott

Still an issue on Measure 32 on os508dx.

The trigger level is adjustable (click on the display field to set the trigger point). I think I understand what you're saying though -- is noise causing a momentary downslope on one or two samples even though the gross trend is upslope and the trigger fires anyway?

comment:3 Changed 13 years ago by walter

If someone has a good handle on how to fix this, I welcome a patch.

comment:4 Changed 13 years ago by godiard

  • Keywords 11.3.0 added; 11.2.0 removed

comment:5 Changed 12 years ago by carrott

On 12.1.0 Build 10 we find that the trigger no longer works at all on XO-1.5 and XO-1.75.

comment:6 Changed 12 years ago by walter

I fixed the logic error that was causing the double trigger. See [1]


comment:7 Changed 12 years ago by walter

  • Resolution set to fixed
  • Status changed from new to closed
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