LEDs won't turn on until two buttons are pressed!?

[Guest xlazyx]

Hello!!

Good to be back at the forum! :D

I recently started fiddleing with my box and decided to add some more LEDs (been using only 8 of them until now). But I though i should check up on something first!

When i press my buttons the corresponding LED lights up, but there are two LEDs that seem to depend on eachother. They wont light up when only one of the buttons are pressed, but only when both buttons are pressed! You would expect that it was something wrong with the LED wirering, but at bootup they all flash ok, and when i change the control to the other 8 buttons i can control them induvidualy. So it's probably something wrong with the button wiring, but when check it with my meter nothing is wrong (cant find anything). Any of you smart heads out there got any idea how this situation can appear? That two leds (or buttons i belive) depend on eachother? This also happens when i send MIDI messages to the box from Cubase telling the box to light the LEDS. Then i must send two NOte ON messages for them to light up.

Any idea???? ???

Thanks!!

Also great to see so many new boxes in the gallery and so much activity in the forums. I'll be writing a small script for MIDI-OX that will work with SX and ill make sure it gets on the site when its finished!

Until next time, good luck and happy soldering! ;D

Tor Arne

[ThomasT]

The LED wiring my be ok, but what about the button wiring?

Are the inputs of the 165 5V? All pullups ok? Do you measure 0V when button is pressed only on this input?

Have the two corresponding LEDs/Button the same MIDI-event?

[Guest xlazyx]

Hey!

I checked up some more on this and this is what i found:

(Note that i have 16 physical buttons, but only 8 physical LEDs, so when i say connect, it means i connect the 8 buttons and 8 LEDs in question to the different OUTPUTS on the PCB!)

1. When the box boots, I DO have the same problem.  The two LEDs light only together!

2. The MIDI events for the two buttons (or any button) are not the same.

3. When i connect buttons 1-8 to LED's 1-8 (my usual setup) LEDs 5&6 will only light up when button 5&6 are pressed at the same time.

4. When i connect buttons 1-8 to LED's 9-16 LEDs 13&14 will light up like normal, independently of what button (5 or 6) is pressed.

5. When i connect buttons 9-16 to LED's 1-8 LEDs 5&6 will only light up when button 13&14 are pressed at the same time.

6. When i connect buttons 9-16 to LED's 9-16 LEDs 13&14 will light up like normal, independently of what button (13 or 14) is pressed.

All this points to one thing: There is something wrong with the PCB LED output 1-8. Because it will malfuntion even when controlled by button INput 1-8 or 9-16. And the physical LEDs 1-8 will work fine when connected to PCB LED output 9-16. So there is nothing wrong with the acutal LEDs, only the output to them (output 1-8).

So, what can then be the fault? It's been a long time since i did my box and I've forgot some stuff about what to measure to see if something is wrong, and I don't want to shortcircuit my box!

Hope someone can understand this!

Thanks!

Tor Arne Vestbø