random midi patterns

Testing/Troubleshooting
1

hi all!

yeah i know… discussed a few times ago but all the threads don’t really solve my problem

built my box, troubleshooted it

loaded up mios –> no problem

loaded up midibox v 2.3 –> big problem

setup of the box:

  • core module

  • 1 ain

  • 1 din

no lcd, nothing else

i get a lot of random midi events. seems that it’s a pattern everytime but not always the same. events come in at every port.

the patterns always include brightness, volume, reverb depth, chorus depth. at power off there are many other events but i think they come from the descending tension of the power supply

if i load up the main.sys from the ain64_din128_dout128_v1_3 file i get random events only on port 2 (perhaps that’s a little hint)

to get a ground line i soldered a cable at the bottom of the core at one of the outer lines where the rectifier and so on goes through. all the things bellow merge at this cable

A3-A7 of the core are grounded

chassis grounded

problem persists

resistance between ground+chassis 0,23 ohm and tension of 0,001V … should not be the problem i think

tension at output of the ain 5,073V like on other measurement points at the core

i also tried to disconnect a0-a3 (and ground them). also disconnected RC,SC,S1 then and grounded them too but same old story

arg … i don’t know how to go on with my troubleshooting.

perhaps someone can help me … hope so

greez

2

ok here are some news:

figured out that i had some problems with my cables and fixed it. but now the problem still persists. but a few changes: now i get (with midibox 2.3) only chorus depth and reverb depth events. if A3-A7 of the core are released from ground i get volume, brightness and portamento ctrl events too.

i also have replaced the 4051 by new ones but this didn’t help.

3

Hi,

Do you have open Ports on the AIN Module ? -

If yes - clamp them to ground.

Just for a test: Do you get random events also, if you disconnect the AIN Module ?

greets

DOC

4

no there are no open inputs … all 32 pots are connected

checked my connectors again and again there was a faulty contact… but fixed it.. now all connections have to work. and i’m getting only chorus depth events. even if i disconnect the ain

also if i disconnect the din too

greez

5

Sorry,

no further advice then…

maybe someone else ???  ??

greets

DOC

6

thx anyways :o)

this sux! i just was happy to get a upload request message and thought i’ll be finished in a couple of minutes and then this… debugging again

i’m now downloading mplab and i’ll try to make a individual syx file. perhaps it will help

7

Hi,

I have the same problem of random midi events, but I don´t use a LCD. Have you solve it??

Thanks.

Kelper

8

Mhhh,

still sounds strange…

Several hints (which helped me in my SID projekt a time ago)…

Take a look at your midi cable.

  1. Take care that the connections between Core and the midi connector are very short.

  2. Disconnect the ground pin from Midi Out on the core (J12).

  3. If the connection between Core (J12/J13) and your Midi Connectors are longer than 20cm, use a shielded cable. But don’t connect the shield on the connectors, just on the Core Ground (leave the shield connection from the Midi-Connectors open)

  4. Perhaps you can test on any ground loops also. Try to ‘bundle’ your ground connection in a central point. But don’t do this at the ground lines of your Pots.

I suggest to connect every 8 or 10 pots to a central ground-point. Not all pots on one ground connection.

(I think this couldn’t be the reason, because you get the events even with no pots connected, right ?)

Please keep in mind, that these hints are jut suggestions on what I would do (or try)…

Hope it helps …

Doc

9

ok news again:

first of all i downloaded mplab and made a new main.syx configured to my needs (only changed number of pots and buttons… hope thats enough)

ground pin lift did not work

now i use an isolated cable and this didn’t help too. but i figured out something new. in the midi flow of chorus depth events there are other events when i’m moving the pots … so the pots seem to work. i also get the flow only on port 1 to 8 and if i move a pot there is activity on the correspondending port. i don’t know if the buttons work because i think it’s too fast to see it because i think pots send much more values so that i can see it.

perhaps thorsten could help hehe

i don’t think that this comes from a false component or so because they are almost all from reichelt and the same as on the lists

10

ok…fixed some problems (short on the ain) but still getting events. but im on the hunt for it and think that it soon will be found. more news tomorrow ;o)

greeez