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AOUT problem


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Hi

 

I feel i ask a lot of questions on this forum, but i am very grateful for all the answers

 

I am currently building the AOUT (orig version) and i just finished the bipolar PSU, plus the board and tried hooking everything up to the my LPC1769 core

 

The LED lights up on the AOUT and i am running the AOUT tutorial, but i can't figure out if everything is working correctly. I have tried measuring the different outputs on the board with my multimeter but i get a constant reading of around -10v on all outputs, thinking this isn't correct

 

I am sending loads of different notes and velocity and i can't seem to get it to change values. I had first plugged it in without the bipolar PSU, but figured out that this was actually necessary for the tl074, so i am a little worried these might have taken damage? I think i will try to swap them out and test again and otherwise go somewhere i can measure with an oscilloscope instead.

 

Any ideas or experiences? I tried searching but couldn't find very much about the AOUT

 

Thanks again for all the help!

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The Gate LEDs don't light up either, shouldn't they be doing that in the tutorial application? I think i should try and just run through all connections on the aout board. It might also be the 6007b shunt which isn't sitting correctly. 

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The gate LEDs are a good indicator, if the Core->MAX525 communication is working or not, because an unconnected bipolar PSU or shunt won't affect this.

 

Apparently the communication is not working, otherwise the gates would be enabled whenever a note event is played.

 

Just to doublecheck:

 

I guess that you are trying this example: http://svnmios.midibox.org/filedetails.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2Fcontrollers%2Fmidibox_ng_v1%2Fcfg%2Ftests%2Fcvnotes.ngc

 

Did you change:

AOUT  type=AOUT_NG  cs=0  num_channels=8

to:

AOUT  type=AOUT  cs=0  num_channels=8

to select the right protocol?

 

If yes: doublecheck the connections between AOUT module and MBHP_CORE_LPC17::J19.

 

Best Regards, Thorsten.

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The gate LEDs are a good indicator, if the Core->MAX525 communication is working or not, because an unconnected bipolar PSU or shunt won't affect this.

 

Apparently the communication is not working, otherwise the gates would be enabled whenever a note event is played.

 

Just to doublecheck:

 

I guess that you are trying this example: http://svnmios.midibox.org/filedetails.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2Fcontrollers%2Fmidibox_ng_v1%2Fcfg%2Ftests%2Fcvnotes.ngc

 

Did you change:

AOUT  type=AOUT_NG  cs=0  num_channels=8

to:

AOUT  type=AOUT  cs=0  num_channels=8

to select the right protocol?

 

If yes: doublecheck the connections between AOUT module and MBHP_CORE_LPC17::J19.

 

Best Regards, Thorsten.

 

 

I am actually running the 016_aout tutorial, but maybe i should try out this example you're giving here.. 

 

I have connected the J19 like this: 

   J19:Vs -> AOUT Vs
   J19:Vd -> AOUT Vd
   J19:SO -> AOUT SI
   J19:SC -> AOUT SC
   J19:RC1 -> AOUT CS
 
That should be correct, right? It is taken from the readme in the 016_aout tutorial. 
 
I'll just run through things and doublecheck here and there :)
 
Thank you Torsten
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OK, i doublechecked the connections between core and aout and it seems it is correct. 

 

When i turned on the core the first time afterwards, the red led on ch 1 lit up for a few seconds, but when i rebooted the core it didn't do it again. Something isn't right with the connections and i am going through my soldering work on the AOUT now.... hmmm!

 

I also checked all the power supply connections now and they also seem to be good - ie. +/- 12v for the tl074 and 2.048 for the max525 (i measured 2.050, should be ok, yeah?)

Edited by istel
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  • 2 weeks later...

Ok, so i just got away from this a little while and came back with fresh eyes. The b11 and b12, b21 and b22 etc are supposed to be connected with jumpers on the male pin headers if i just want unipolar out, right? If i want bipolar i can make the little schematic shown on the AOUT page with a trimmer and some resistors...

 

I am now going to check out if there is any problems on the core, since i get quite irregular results when i turn on the core - for instance the red LED just lit up on channel 1 and yesterday it did on channel two. Doesn't seem like there is any bad connections on the AOUT board, so i am thinking it is something from the core..

Edited by istel
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The b11 and b12, b21 and b22 etc are supposed to be connected with jumpers on the male pin headers if i just want unipolar out, right? If i want bipolar i can make the little schematic shown on the AOUT page with a trimmer and some resistors...

 

yes, but this shouldn't make a difference for the gate LEDs - please focus to debug this first (yes, maybe there is a problem with J19 of the core module)

 

Best Regards, Thorsten.

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yes, but this shouldn't make a difference for the gate LEDs - please focus to debug this first (yes, maybe there is a problem with J19 of the core module)

 

Best Regards, Thorsten.

 

Sure. This is correct right:

 

   J19:Vs -> AOUT Vs
   J19:Vd -> AOUT Vd
   J19:SO -> AOUT SI
   J19:SC -> AOUT SC
   J19:RC1 -> AOUT CS
 
I just can't find any mentions of the AOUT and the LPC1769. This is taken from the 016_aout tutorial where it is the STM32 which is being discussed. But as far as i understand it should be the same for the LPC?
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