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  #1  
Old 04-05-2014, 03:27 PM
Mac Mac is offline
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Default MIDI indicator LED

Hi:

I recently purchased an MPA 10k pot version.
My intent is to use it for triggering and pitch bends on various bent
circuit toys I have been working on.

After assembling I connected a fresh 9v battery and and a MIDI cable from my
MIDI controller keyboard set to midi channel 1.

On power-up the MPA Red indicator light flashes once > a good sign

After no MIDI signal is indicated by the flashing red light I switched the DIP
switches to all on > nothing > switched back and forth between all DIPs
on and off …. finally I got some MIDI flashing when playing notes and also when rotating the pitch joystick and went to bed happy dreaming of taming the sounds of some very rude toys.

next day …. red light when I fire it up ... no MIDI flashing light indication .... All dip switches were flipped to on then off then on then off again a number of times … re-plugging in the battery after each flip to reset it.

I tried a few more MIDI routes other than the original keyboard MIDI out into
MPA MIDI in … I always get a red light flash whenever battery is first plugged in.

A list of routes tried:

1) keyboard MIDI out > MPA MIDI in … no flashing red light for MIDI (only worked once)

2) keyboard MIDI out > MPA MIDI in > MPA MIDI thru to an RME Fireface MIDI in …. no flashing red light … on the RME Fireface however I get two yellow MIDI indicator lights that both stay on permanently (normal state for one light but the other usually only flashes when there is midi activity) is this a clue?

3) Cubase MIDI note sequence to RME MIDI in (both flashing yellow lights indicates active MIDI) > MPA MIDI in ….. no flashing.

3) Keyboard MIDI out and Cubase MIDI note sequence to RME MIDI in (both flashing yellow lights indicates active MIDI) > MPA MIDI in ….. still no flashing.

To test the MPA Do I need to have the MPA wired to some triggers or pitch bend points for
the red MIDI indicator light to flash? or will the MPA flash upon MIDI input with only the MIDI in plugged in?

Do I need to have something plugged into the MPA MIDI thru for MIDI in light flashing to work?

I downloaded a SysEx app for both my Mac and my PC in anticipation of
needing it. here is the txt file (see below) I ran thru your cool little SysEx convertor.

http://support.codeandcopper.com/txt-to-syx/

Maybe the MIDI red light flashes I got early on were a fluke … I thought I could get by with just the original out of the box firmwear settings. I haven't tried sending a SysEx replacement yet .... I am re-reading both manuals again to
see if there is anything I missed.

UPDATE: I checked and re-checked all solder points under a magnifying glass to be sure they were all sound and touched up any one that was slightly suspect. I made sure that there were no bridges. I checked the direction and reseated all the IC chips ... all good. I assume that the female MIDI socket numbering system is when you stare straight at the front side of it where you plug in the male plug .... if so all is good there.

I went thru all of the same MIDI routes as above and got the same results. no MIDI flashing indicated by the MPA.

If you have any work-around or insight gleamed from my description pleaselet me know.


THANKS
MAC




F0 00 01 5D 01

00 02 00
00 02 01
00 02 02
00 02 03

00

00 3C
00 3D
00 3E
00 3F
00 40
00 41
00 42
00 43

00 00 00 00

00 00 00 00 00 00 00 00

F7

Last edited by Mac; 04-07-2014 at 12:40 AM. Reason: Clarification, checked solder, IC directions, re-tested all routes
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  #2  
Old 04-09-2014, 09:53 PM
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John John is offline
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Hi Mac,

Welcome to the forum.

The MPA DIP switch controls the MIDI channel for MPA outputs that do not have an explicit channel set in the configuration sysex. By default, and in the sysex you have posted, that means all outputs (logic and pot).

Changes to the DIP switch only become active at power-up. So if you make a change while the MPA is already running, it will have no effect.

For more information see the section "DIP Switch Channel
Selection" on the last page of the MPA firmware user manual.

During normal operation, the MPA activity LED will only flash when a message is received that matches one of the outputs. There is also an "Activity Indicator LED" section in the MPA firmware user manual with more details.

To summarize the above, you probably are not getting an activity indication because the MPA is not receiving a MIDI message to match any of its outputs.

If the MPA still has the factory configuration, you can trigger an activity indication by doing the following:

1. Set all DIP switch positions to "off". (For channel 1)
2. Send a MIDI "middle C" note to the MPA on channel 1 (note number 60)

If you want a sure way to send a note #60, you can use SendSX on your PC to send the hex code:

90 3C 7F

That is the code for a middle C note-on message with velocity of 127 on MIDI channel 1.

Please let me know if that helps you to reliably see an activity indication from the MPA. From there, we can continue the discussion.
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Old 04-09-2014, 10:39 PM
Mac Mac is offline
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Join Date: Apr 2014
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Default MIDI indicator LED cont

Hi John:

Thanks for the reply.

>If the MPA still has the factory configuration, you can trigger an activity indication by doing the following:

The MPA is still set to the factory config. I was just prepping myself on the sysEx in case you might see it as a possible solution.

>1. Set all DIP switch positions to "off". (For channel 1)
>2. Send a MIDI "middle C" note to the MPA on channel 1 (note number 60)

All DIP switches set to off, MIDI channel set to channel 1 on my Keyboard controller … hit middle "c" tried every other key in every octave to be sure. also sent joystick info to try and trigger the pots

Tried sending every MIDI note up/down the scale from Cubase set to MIDI channel 1 thru my RME Fireface, still no flashing on the MPA. For good measure I also set all DIP switch positions to "on" and set all MIDI input devices to channel 16 … still no response. I did remember to re-power up the MPA to reset the DIP switch change.

The keyboard and the Fireface have no problems communicating MIDI … in fact the MPA passes the signal thru when it is powered up …. I just can not get the MPA LED to indicate it is itself receiving MIDI by flashing its LED.

Do you have a next course of acton?

Thanks again
Mac

Appended:
Fired up SendSX and sent hex code 90 3C 7F ... Still no MIDI LED flashing. SendSX claimed a successful send but the MPA did not flash 3 times to indicate a successful receive.

Last edited by Mac; 04-10-2014 at 02:53 PM. Reason: Tried to send hex code
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  #4  
Old 04-16-2014, 04:22 PM
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John John is offline
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Quote:
Originally Posted by Mac View Post
Hi John:

Thanks for the reply.

>If the MPA still has the factory configuration, you can trigger an activity indication by doing the following:

The MPA is still set to the factory config. I was just prepping myself on the sysEx in case you might see it as a possible solution.

>1. Set all DIP switch positions to "off". (For channel 1)
>2. Send a MIDI "middle C" note to the MPA on channel 1 (note number 60)

All DIP switches set to off, MIDI channel set to channel 1 on my Keyboard controller hit middle "c" tried every other key in every octave to be sure. also sent joystick info to try and trigger the pots

Tried sending every MIDI note up/down the scale from Cubase set to MIDI channel 1 thru my RME Fireface, still no flashing on the MPA. For good measure I also set all DIP switch positions to "on" and set all MIDI input devices to channel 16 still no response. I did remember to re-power up the MPA to reset the DIP switch change.

The keyboard and the Fireface have no problems communicating MIDI in fact the MPA passes the signal thru when it is powered up . I just can not get the MPA LED to indicate it is itself receiving MIDI by flashing its LED.

Do you have a next course of acton?

Thanks again
Mac

Appended:
Fired up SendSX and sent hex code 90 3C 7F ... Still no MIDI LED flashing. SendSX claimed a successful send but the MPA did not flash 3 times to indicate a successful receive.
Hi Mac,

Can you double-check the orientation of IC2? If reversed, it will prevent the MIDI signal from getting in to the MPA. Since you are observing the LED self-test upon power up, it seems that IC1 is healthy.

I will follow up via PM.
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  #5  
Old 04-16-2014, 06:53 PM
Mac Mac is offline
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Join Date: Apr 2014
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Default IC 2 direction

Hi John:

Checked the IC2 and it is and has been facing in the right direction.


Thanks again for your assistance
Mac
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