Hello Flow75,
You're encountering an exception related to the EveryNSamplesWritten event because the Data Transfer Mechanism (DMA, USB Bulk, or Interrupts) imposes constraints on the buffer size and the sample interval.
You have here two different options to solve this issue:
- If you don't necessarily need to use EveryNSamplesWritten, the best approach is probably to send the samples in chunks (chunkSize) at regular intervals. This would allow you to manually update your progress bar.
To do this, you can take inspiration from the small code snippet structure below.
while (written < totalSamples)
{ int remaining = totalSamples - written;
int currentChunk = Math.Min(chunkSize, remaining);
double[] buffer = new double[currentChunk];
Array.Copy(signal, written, buffer, 0, currentChunk);
writer.WriteMultiSample(false, buffer);
written += currentChunk;
Console.WriteLine($"Progression : {written * 100 / totalSamples}%");
Thread.Sleep(100); // <-- Simulate the regular interval }
However, while this method provides a practical workaround, it is not true hard real-time. Still, it’s often sufficient for generating simple analog signals.
If you’re working with a high sampling rate, you’ll also need to adjust both chunkSize and Thread.Sleep() to avoid underfeeding the device.
- If you absolutely want to use EveryNSamplesWritten, you’ll need to make sure the buffer size is an exact multiple of N.
However, be aware that not all modules and configurations support this approach (which is what your error message is indicating), so in many cases it's better to rely on your own progress logic, like in the first method using chunkSize.
