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A lot of midi message when I connect a DIN


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Hi,

I'm having trouble with DIN R5, just insert the ribbon on J1 and I receive on midi in an avalanche of messages (Buttons-note on / off).
I'm working on NG Default but I have tried also with Midio128, same problem. I tested resistance and welding on DIN and it all looks ok.
Have any of you ever encountered this problem?

 

Thank you.

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Hi,

 

my first guess would be a short somewhere. That is sort of what a button would do, it would close the circuit between a DIN pin and ground.

 

What kind of key values are recognized in Mios Studio when you are using the NG Default script? Maybe this could help narrowing down the error?

 

my regards

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Hi,

I think it is also a short, on mios in default NG I receive continuous signals of buttons and related notes.

I tried to do a test with a simple Hello.NGC but same problem, mios appears on a continuous data stream "chn # 1 note on/off C1" of course the code is : EVENT_BUTTON id = 1 = LED fwd_id: NoteOn key = 1 type = range = 36 0:127 lcd_pos = 1:1:1 label =" Button #% 3i:% 3d "

Another thing that seems strange to me is that the red LED is continuously lit on the LPC1769 ..... this is right?

 

Tnx a lot for your help ;-)

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Hi,

 

the red led on the LPC17 core is lit, when some kind of data is processed (like the hdd led on a computer). If there´s a short on the DIN module this would be normal since it processes data continously (impulse from din -> midi data out).

 

I´m a little confused about that button event you posted because it wouldn´t really make sense if it looks that way. Did you post it here exactly like in the *.ngc file?

 

To test a bit further, I´d suggest you create a new *ngc file and insert some simple button events with an id from 1 to 32 and the midi event NoteOn and key from 1 to 32 (to test all input pins on the DIN):

 

EVENT_BUTTON id=1 type=NoteOn key=1

EVENT_BUTTON id=2 type=NoteOn key=2

EVENT_BUTTON id=3 type=NoteOn key=3

EVENT_BUTTON id=4 type=NoteOn key=4

........

EVENT_BUTTON id=32 type=NoteOn key=32

 

After that you load it and look at the midi in monitor inside Mio Studio. If there is a continous stream of midi events still coming in, just let it stream for a few seconds and then cut the power of the LPC17 core (to stop the stream ).

 

Then you can study the stream and see, what kinds of notes appear in it. This could help narrowing down where the short sits.

 

my regards

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Hi,

about your answere :

 

the red led on the LPC17 core is lit, when some kind of data is processed (like the hdd led on a computer). If there´s a short on the DIN module this would be normal since it processes data continously (impulse from din -> midi data out).

 

The red led is continously lit even without DIN..... and I begin to believe that the short is on the core :-(

I tried with your code but same problem, practically is like an open flow of data streaming, any event that I assign to a DIN (and I tried with 2 different DIN) back as a loop on the midi monitor, below a link for a screen shot of the Mios so you can see the data message.

 

https://www.dropbox.com/s/9b3qlhl83eggggq/Screen%20Shot%202013-08-26%20at%2016.11.27.png

 

I did also a test on resistance (R9) on the core but it seems this is not the problem.

If you have an idea about this problem I would be eternally grateful.

 

Tnx a lot .

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Ok, after your additional descriptions it really seems that there is a problem on the LPC17 core. The problem on my side would be to narrow down where this problem is, a remote diagnosis from here can be very hard.

 

You can try/check a few things:

 

1. What kind of computer are you using? PC or MAC?

if you are on a PC, I suggest you install the gm5 driver, it´s much more stable than the native windows driver.

 

2. Visually inspect all the soldering points on the board.

 

3. If you have access to a multimeter, check the complete core for the expected voltages (look at the LPC17 schematics).

 

4. Check all the parts, especially those which has a polarity and all the ICs if there are put in the right way.

 

my regards

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Hi,

I tested everything following the schematics and everything seems to work fine, all voltages are correct, at least the ones described (+3.3 V +5 V-)

and each IC is in the correct direction.

Also tested resistance, ok.
About the computer I use Mac but I don't believe the problem is on the driver.
The thing  I need to understand is why even without plug the DIN the led2 of the LPC remains continuously red, I think this is a clear sign that the problem lies in the core of the LPC but where?

 

Thank you.

 

Regards.

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Hi Duggle,

I did a test, I only tried with the slot J3, I started to put in ground from D0 and so on and at the moment that I put on ground D6 data cycle stops "NO EVENTS"
Regarding the DIN "R5" I loaded 8 network 10k (obviously with the poles in the right place) and 4 capacitors 100nf, I hope this board do not need more resistor....

 

 

Tnx a lot.

 

Regards.

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Hi,

 

The thing  I need to understand is why even without plug the DIN the led2 of the LPC remains continuously red, I think this is a clear sign that the problem lies in the core of the LPC but where?

 

for the MBNG application this is normal, the LED is toggled with a very high frequency so that it looks like it's permanently lit.

So, the issue is probably not related to the core module.

 

Are you sure, that the ribbon cable is connected correctly?

E.g. as far as I remember, a continuous stream will be generated if the cable is cable is plugged in the reversed direction into the socket.

 

These pictures might help to doublecheck this (they are for a different module, but with the same socket polarity):

http://www.ucapps.de/mbhp/mbhp_dio_matrix_7.jpg

http://www.ucapps.de/mbhp/mbhp_dio_matrix_8.jpg

 

Best Regards, Thorsten.

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Hi Thorsten,

 

The cable is positioned correctly, I tested with the same ribbon 2 DOUT and an  AINSER64 and everything works correctly, instead on 2 DIN the same problem, I re-tested the resistors and also tried chance IC's but no improvement,  what tests can I still do?

 

Tnx a lot.

 

Regards.

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Hm... let's do some additional checks:

 

- what happens if all 74HC165 are removed?

Expectation: no MIDI events should be sent

 

- what happens if only the first 74HC165 is plugged into the socket?

Expectation: MIDI events for the first 8 pins should be sent whenever D0..D7 inputs at J3 are grounded. No continuous toggles should be generated.

 

- what happens if the DIN module is connected, and J8/9:SI is directly connected to Vs (ground) with a short wire?

Expectation: once you connect the cable, many Note On events should be sent, but only once. Thereafter no additional events should be generated anymore.

Once you disconnect the cable, many Note Off events should be sent, but again only once. No repeating note on/off...

 

Best Regards, Thorsten.

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tested and.....

without 74HC165 "no midi event"
With the first 74HC165 assembled and all the pins grounded "No midi events"

With the DIN module connected and J8/9:SI  directly connected to Vs I receive just some events "only note on" than no additional events.

but when I disconnect the cable again continuos signal of note  off/on :-(

 

Thank you.

 

Regards.

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With the first 74HC165 assembled and all the pins grounded "No midi events"

 

but you get a MIDI event whenever a ground connection is done (and removed)? Just like if you would push a button?

 

 

 

With the DIN module connected and J8/9:SI  directly connected to Vs I receive just some events "only note on" than no additional events.

 

I forgot to mention, that the DIN module should not be connected for this test.

However, the result is like expected.

 

 

 

but when I disconnect the cable again continuos signal of note  off/on :-(

 

You notice this, when DIN module is connected, right?

What happens if the DIN module is not connected, and you repeat this test?

 

And please also do the test with the single 74HC165, because it seems that with a single chip no continuous note off/on will be generated, right?

Or does this mean, that they won't be generated if all digital inputs (D0..D7) are connected to ground?

 

Best Regards, Thorsten.

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but you get a MIDI event whenever a ground connection is done (and removed)? Just like if you would push a button?

 

I get a midi event only on pin D7

 

You notice this, when DIN module is connected, right?

What happens if the DIN module is not connected, and you repeat this test?

 

Yes without DIN is correct, On when I connect and Off when I disconnect.

 

And please also do the test with the single 74HC165, because it seems that with a single chip no continuous note off/on will be generated, right? Or does this mean, that they won't be generated if all digital inputs (D0..D7) are connected to ground?

 

Best Regards, Thorsten.

Right, with the single chip no continue on/off if DO..D7 is connect to ground.

 

Thank you.

 

Regards.

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I come to the conclusion, that this issue is matching with 

 

- MIDI monitor logs shows exactly the same behavior (rapid note on/off toggles)

- D7 triggers MIDI events

- SI input is working

 

Geth fixed this by re-soldering every connection of the core module.

I think that it should be sufficient to re-solder all pins which go to/come from IC1 (74HCT541)

Especially J8/9 SC & RC1/2, Pin #12/13/14 of IC1, Pin 7/8/9 of IC1, P0.9, P0.7, P0.6 of the LPCXPRESSO.

Maybe also the power related lines (Vs/Vd) to J8/9

 

Best Regards, Thorsten.

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