Pin 40 Issue

[sbonasuk]

Using the slide potentiometer method for the hi hat, worked fine for a few seconds then MG stopped restarted,continuous midi signals from pin 40 until the only way I could get it to stop was to ground pin 40. I suspected that perhaps the firmware had corrupted in some way so tried to reload but the software give the MG does not respond "msg". Do I need to get the Atmega re booted.

[dmitri]

I've never heard Atmega or ARM corrupting its firmware during normal use. The firmware may get corrupted only by an interrupted firmware upgrade. For a fail safe firmware update/recovery use procedure in viewtopic.php?f=3&t=1252

[sbonasuk]

Thanks that worked fine. However any thoughts why taking a lead from gnd to the pin 40 net stops the continuous midi output .

[dmitri]

Pin 40 on the kit? You short HiHat controller's power to ground so no more signals from it.

[sbonasuk]

The issue that the 4 bars of pin 40 show continuous output on the screen with the led always lit. If I take a lead from the circuit gnd and short it to anywhere on the output net the it stops and all's well. Only started when I tried to connect a sliding potentiometer on the 38/39 Hihat circuit.

[dmitri]

Sorry, I don't understand what you're trying to do and what the problem is.

[sbonasuk]

When I switch on MD, normal sequence however the first 4 blocks on the VDU are full, and when connected to MDM it shows constant midi activity. This first started when I was attaching a hihat foot pedal made with a slide potentiometer. I checked for any broken tracks or dry joints, loose cables etc, nothings seemed out of place. By accident checking for shorts i put a cable from the GND circuit of the board and the other end on a track coming from PIN 40 and the midi activity stopped and everything returned to normal. So the questions are why does grounding the pin 40 circuit stop it from producing an output, and what possibly started it in the first place Further more you can put the end of the cable from earth on any of the output pins 34 35 etc and pin 40 will drop the output


thanks

[dmitri]

You either damaged the MUxer, or, more likely, you still have breaks between Atmega and this MUXer, in particular to pins 9, 10 and 11 of this MUXer.

[sbonasuk]

You are right there is a dry joint or break somewhere, it was a fluke that touching the pin stopped it, Time to rebuild the board. all the chips are new, it has to be a physical break.

Thanks again

[sbonasuk]

And sure enough after the new board was built the problem went away thanks Dmitri.

Would the 56i single sided board, update to the ARM based chip using a Surface mount to TTH converter without too much effort or is the board layout so completely different, and would it be worth the effort.