Benchmarks

[Synthex]

I did some response time tests of the 32 inputs @ 20MHz version.
The average response time is 9 ms.

On the chart, the first line is the piezo signal, the second line is the Midi signal.

[Goldie]

Is soundcard latency included in 9 ms? Because 2nd waveform looks like sound to me. Can you please explain how you did it. And would it be possible to record midi note on as short click. This would give us best results.

[Synthex]

Is soundcard latency included in 9 ms? Because 2nd waveform looks like sound to me. Can you please explain how you did it. And would it be possible to record midi note on as short click. This would give us best results.

No, the soundcard latency is not included. the 2nd waveform is numeric MIDI signal.
I plugged directly leaving the Atmega32 on my sound card (as an oscilloscope).

[Goldie]

Ok, good job.

[Synthex]

Roland brains seems to be less than 4 ms.

Is it possible to reduce this latency in a future version of the firmware ?
(code optimization, higher frequency, ...)

[dmitri]

Strange. Unless I made a mistake somewhere, the delay should be no more than 4ms. How did you measure it? And what did you mean by 'average 9ms'? Are there minimums and maximums? It should be pretty much a constant.

[Synthex]

Strange. Unless I made a mistake somewhere, the delay should be no more than 4ms. How did you measure it? And what did you mean by 'average 9ms'? Are there minimums and maximums? It should be pretty much a constant.

I use a sound card to record the gap.
I make a recording in stereo : right channel = piezo, left channel = TX output of Atmega32.
I found response times of between 7 and 10 ms.

I may be wrong ...

Have you ever done these measures ?

[Goldie]

Roland SPD-6 = 5ms delay

Left channel - mike on SPD pad
Right channel - SPD midi out through Di box

Just had to try it. It's possible to record midi out. It sends pulse all the time, i guess active midi sensing. 222 samples delay @44,1 khz. Dmitri 4ms would be excelent.

[dmitri]

I'll try to make measurement myself

[dmitri]

Synthex, try these two versions for 22 inputs:
16MHz:

megadrum32_16.hex

20MHz:

megadrum32_20.hex