Random MIDI messages from a pot?

[neilneil]

Hi, i built a CORE board made by smashTV (thank you very much Smash!)

ive added a single pot (10k linear) to it and i get no output from half of the turn of the pot and seemingly random MIDI messages from the other half, could i have missed something out in the MIOS  upload or the MIDIbox 64 editor?

All unused pins i have grounded (i think)

I REALLY am sorry if this has been covered elsewhere, i couldnt find an answer.

Point me in the right direction and tell me to look better before asking if you dont have time to answer.

Cheers

Neil

[goyousalukis]

Hey Neil,

It really sounds like you either have the pot wired wrong, or you have a faulty pot. You have one side connected to ground, the other side to 5v and the middle to the A0 pin on the Core module? Double check that A1-A7 are connected to ground. Of course, if you have another pot, try that out.

Justin

[stryd_one]

Make sure you follow all the guidelines in the wiki for testing pot jitter...

First thing, are all the unused AIN pins grounded?

[neilneil]

Thank you very much for replying!!!

i have deffinately got one side connected to 5v the other to Vs and the middle terminal to A0 on the CORE module. Ive tried a couple of pots. And i dont have an AIN connected.

The unused pins of J5a on the CORE are connected to the Vs on J5a and unused on J5b are connected to Vs on J5b

Sorry if im doing something really stupid here.

[nebula]

Did you try a different pot, just to be sure?

[neilneil]

Yeah, ive tried 3 different ones.

I went over the circuit resoldering some parts and took out the pot, then put it back on and resoldered the connections between ground for all the unused pins, now i dont get any message when i turn the pot! i have no idea whats happening.

When you upload the application from the MIDIbox 64 editor should it confirm that the application has been succesfully loaded?

Thanks again!!!

[goyousalukis]

Ok, so I guess you don't have a LCD hooked up to confirm the application is running?

Just to make sure, the steps to load the PIC are:

1: burn the bootstrap loader with a PIC programmer (unless you bought it pre-burned)

2. Upload MIOS - you should use MIOS Studio if possible. When you send the data, you should get the messages confirming each block uploaded correctly.

3. Upload the Midibox 64 application(with MIOS Studio - not the midibox 64 editor). The editor is for modifying the configuration, not for uploading the application.

If you then boot up the core module with no pots connected, you will get lots of midi data on lots of channels.

If you turn it on with all the inputs grounded except one, you'll get lots of midi data on just one channel.

I wouldn't mess with the midibox 64 editor, until you get the core running.

Another thing, If you don't have an AIN module connected to the Core, you need to change a flag in the Main.asm file and recompile the source code - this is from that file:

 Number of connected pots
; Allowed values: 1-64
#define DEFAULT_NUMBER_POTS 64 ; number of connected pots
;
; Multiplexers (AINX4 modules) connected? -> set this value to 1
; No multiplexer connected= -> set this value to 0, allowed number of pots in this case: 1-8
#define DEFAULT_MUX_ENABLED 1 ; enable multiplexers

I'm not sure if there is another way to change this without re-compiling. Let me know if you don't know how to do this... I could do it and email the .hex / .syx

Hope this info helps a little....

Justin

[neilneil]

I have an AIN module, i hooked it up and now the PIC doesnt appear to even send a startup message!

Have i just killed my PIC?

If i get this fixed i will then try and upload the app through MIOS studio.

Thank you Justin for pointing that one out! (about virtual 64)

Thanks

Neil

[goyousalukis]

You don't have to have the AIN hooked up to load MIOS and the application.

It is possible you have a short that is preventing the PIC from starting. Use just the core, and see if you get that startup message. Then try to load MIOS, and then the Application(MB64).

I doubt if you fried the PIC.  I have done some horrible things to PICs (Accidentaly of course!) and they haven't fried, but it is possible.

If at all possible, I highly recommend you get a LCD - even just a little 2x16 non-backlit type. It will make it so much easier to troubleshoot. You will know when you've loaded MIOS, and when you've loaded the application.

Justin