Account for two tick delay in sample counter on DigitalIO device

jonnew · jonnew · commit 58a018f3ca3c · 2025-08-07T15:37:55.000-04:00
- This is known issue in version 2 of the DigitalIO device. This
  correction results in the digital sampling rate matching the value
  specified by SampleRate
diff --git a/OpenEphys.Onix1/ConfigureDigitalIO.cs b/OpenEphys.Onix1/ConfigureDigitalIO.cs
@@ -116,7 +116,7 @@ public override IObservable<ContextTask> Process(IObservable<ContextTask> source
 
                 if (sr is not null)
                 {
-                    var periodTicks = (uint)(baseFreqHz / sr);
+                    var periodTicks = (uint)(baseFreqHz / sr) - 2; // NB: -2 results from known issue in version 2 of DigitalIO device
                     device.WriteRegister(DigitalIO.SAMPLE_PERIOD, periodTicks);
                 } else
                 {

Original file line number	Diff line number	Diff line change
`@@ -116,7 +116,7 @@ public override IObservable<ContextTask> Process(IObservable<ContextTask> source`
`116`	`116`
`117`	`117`	`if (sr is not null)`
`118`	`118`	`{`
`119`		`- var periodTicks = (uint)(baseFreqHz / sr);`
	`119`	`+ var periodTicks = (uint)(baseFreqHz / sr) - 2; // NB: -2 results from known issue in version 2 of DigitalIO device`
`120`	`120`	`device.WriteRegister(DigitalIO.SAMPLE_PERIOD, periodTicks);`
`121`	`121`	`} else`
`122`	`122`	`{`