Question about MIDI LED

[jerzy]

Since I don't have LCD, this LED is my only indicator. I have problems with analog board and I would like to know it's normal behavior. Does it lights up on startup for 1-2 seconds? When I hit the pad, again, it lights up for 1-2 seconds?

[Synthex]

Since I don't have LCD, this LED is my only indicator. I have problems with analog board and I would like to know it's normal behavior. Does it lights up on startup for 1-2 seconds? When I hit the pad, again, it lights up for 1-2 seconds?

This LED lights up on startup for 0.5 second and when you hit a pad, it must lights up less than 0.5 second.
You have a problem with the firmware on Atmega. Check your fuses.

[dmitri]

Or a mismatch between crystal and firmware frequencies.

[jerzy]

So it looks like µC restarts every time I connect +5V to one of pins of AnalogueConnector.1 (and maybe my analog board is fine after all:). I did use firmware file named "megadrum32_20_32_20080209.hex" as I have 20MHz quartz with ATmega32-16PU (maybe mine doesn't like overclocking?) I have used fuse settings from documentation page, but I will check again in a minute.

I did measurement with stopwatch in hand and it appears, that this LED lights for 5 seconds on startup (and also, there is a 2-2.5 second delay, after power-up), so looks like it's 10 times slower than it should.

AC voltage meter shows some activity on Analogue.Connector.2, but I don't have oscilloscope anymore to check what's really going on. Do you think I can use sound card for this? How high is switching frequency on that connector? I'm guessing, that resolution should be about 1ms, so is it around 1kHz?

[dmitri]

The switching frequency on pins of this connector may be up to 50KHz.

[jerzy]

4 channels at 50kHz - thats pretty hi-fi sample rate for those poor piezos:)
Syntex: you were right: I had CKSEL bits set wrong. Thanks:)

[jerzy]

PS.
An ("debug" without LCD) feature request: maybe MIDI LED could blink (lets say) 3 times at boot-up, so there would be visible difference between normal work and one would know if µC just restarts or works fine, without even connecting analog board?