high values of voltage on pin7 IC11 for all octaves

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Deepsky
 
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high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Hi all! I finished assembling my x0xbOx kit (x0xsh0p.de), but...
In keyboard mode the notes in each octave sound too high and some are wrong. :(
So I checked the voltage for each note on pin 7 of IC11, the results are reported in table... I think they are quite wrong :?

Thank you for any help!
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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

Yes, those values don't make any sense. Since I don't see any pattern here I suspect something major must have happened here.

Can you check the voltages on the processor side of IC9 (pin 3, 4, 6, 11, 13, 14) while playing non-transposed G# and A?

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

The voltages on IC9 are:

playing G#:
3 - 4.95V
4 - 4.95V
6 - 4.93V
11- 4.93V
13- 4.95V
14- 4.95V

playing A:
3 - 0V
4 - 0V
6 - 4.93V
11- 4.93V
13- 0V
14- 0V

a few days ago I tried to replace the 74hc174 but I have not solved the problem.

I noticed another thing, but I do not know if it is caused by the same problem: the buttons do not respond immediately, there is about 1 second of latency from the moment I keep them pressed until the LED lights up and you hear the sound, same thing for the transpose keys, accent, and selecting the patterns in "pattern sync out" mode.

Also the tempo knob is not working properly, :? in "random" mode the LED flashes (slowly) but the tempo is not incremented and decremented correctly

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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

This looks like a problem on the digital side.

For G# all looks ok except pin 11 should be 0V,
For A everything looks OK except pin 6 should be 0V.

Please press the lowest (transposed down) C and the lowest (transposed down) F and measure again. If my theory is correct you'll get for the "C" voltages on all pins except pin 4 and for the "F" the same voltages as for your previous measurement for the (non transposed) "A".

My guess is that either the processor is faulty (and puts the two lines on "high" all the time) or there is some (unwanted) bridge that is responsible for this.

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Exactly! I have these values:

playing C (lowest):
3 - 4.95V
4 - 0V
6 - 4.93V
11- 4.93V
13- 4.95V
14- 4.95V

playing F (lowest):
3 - 0V
4 - 0V
6 - 4.93V
11- 4.93V
13- 0V
14- 0V

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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

I'll look into this either later today or tomorrow and I'm quite certain we'll get to the root of this problem.

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Thank you very much for you interest in my problem, I could order a new ATMEGA162 and then check if everything works out ...although I realized that the cost of the part (adding shipping and taxes) is not very economical to be only an attempt

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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

Let's try the following first: Remove the processor, turn on the xoxbox and measure the voltage on pin 6 and 11 of IC9 (no additional action is needed).

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

I have 0.23V on pin 6 and 0.21V on pin 11

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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

OK. Bend away pins 25 and 26 of the processor and re-install it.

Check at those exposed pins what happens when playing G# and A an keyboard mode. Check also pins 6 and 11 on IC9 again.

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Leaving out pins 25 and 26:
4.93V on pins 25 and 26 when playing G # and A
0V on pins 6 and 11 of IC9 when playing G # and A

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mmm
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by mmm »

This definitely looks like a processor problem to me.

You could try two more things before ordering a new one:

1. Check what happens to the MIDI data when playing the xoxbox in keyboard mode. If the MIDI notes are correct this would also hint at a problem with the processor.
2. You could try to re-flash the processor; maybe just the firmware is corrupted.

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Playing a midi keyboard in "midi play" does not sound any note, I tried to change channels on both devices but does not work.
I will try to reinstall the firmware

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antto
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by antto »

he meant setting the x0x to "Keyboard mode" and pressing the pitch buttons on the x0x (which make it play notes, and also send midi notes OUT)
"midi play mode" is for playing notes externally via midi IN

Deepsky
 
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Re: high values of voltage on pin7 IC11 for all octaves

Post by Deepsky »

Sorry, I misunderstood, thanks for the clarification.
I connected the midi output to a synthesizer, but it doesn't sound.

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