POTs dont response

[dj3nk]

Hi dudes.

my mb16 is now nearly ready but i've got a major problem. All pots seem to work ok. i've got 4 rows of 4. Nr1-8 all is fine! But 8-16 something is wrong. Values just go from 3- 125.

Now....when I turn the 2nd pot of the 3rd line (pot 10), the other pots of this line just go with it. I can turn the other pots of the 3rd and 4th row and they work fine. except when i turn the faulty pot to high, ..... then the other are in/decreasing with the amount the bad pot moves.

Also funnily enough, if the bad pot isnt set up too high, I can "adjust" the range the others can go. In example

badpot @ 100  ====> goodpots@97 or sth; all rest of pots in the line arent changeable anymore .

badpot @  20  ====> goodpots adjustable from 5-127

badpot @  15  ====> goodpots adjustable from 0-122

So when I let that bad pot @ about 15 all others work fine. (hmm... 8-16 just working in that smaller range like this example tells you)

I've already tested to plug another 4051 into my ain but that doesnt affect the problem. hope you can help me.

Power and ground rails cant be the prob i think. They go from up to down. (pot nrs:  1,5,9,13  2,6,10,15  3,7,11,15  4,8,12,16). Due pots 1-8 are working so I dont think it has sth do do with. Powercables are all soldered in the middle of the 4 stripe boards (right word???). Every part has been soldered, no coneectors. I cant find any bad soldering or bridges on my ain.

greetz.

[TK.]

which voltage do you measure at the outer pins? Could it be that it changes? It should always be 5V

Best Regards, Thorsten.

[dj3nk]

4,96 - 4,97V  even when the damaged pot is turned high

Should be fine or not? You meant at the outer pins of the pots ?

add:

now no response on 9-16.  I took a new pic and uploaded my code of mb64.

;

; MIOS Application

; MIDIbox64

;

; Hardware related setup:

;

; Number of connected pots

; Allowed values: 1-64

#define DEFAULT_NUMBER_POTS 16 ; 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

;

; Page handling: special option for MIDIboxes stuffed with 16 pots

; if enabled, 4 pages with 16 pot entries are available which can

; be switched with Meta event FF 05 xx

#define DEFAULT_ENABLE_PAGE_HANDLING 0

;

; Number of connected buttons

; Allowed values: 1-64

#define DEFAULT_NUMBER_BUTTONS  4 ; number of connected buttons

;

; debounce counter (see the function description of MIOS_SRIO_DebounceSet)

; Use 0 for high-quality buttons, use higher values for low-quality buttons

#define DEFAULT_SRIO_DEBOUNCE_CTR 32

;

;

nothing more to change than the number of pots and buttons or not ? im gonna have a the 100st look now at my pcm :(

[dj3nk]

checked the connections between ain and core with a multimeter. all seems ok. no shorts. i've measured directly at the pins of the pics so I can be sure its ok.

[TK.]

It isn't a configuration problem - it's very likely that one of the connection is faulty.

You can easily measure the voltages at the outer pins of each pot, and you can measure the voltage between ground and the middle pin - these are the voltages which are converted by the internal ADC of the PIC. This should help you to locate the error

Best Regards, Thorsten.

[dj3nk]

okay on the way :) hope ill find it soon

[dj3nk]

all voltages are okay. ive checked all pots from left-right left-middle right-middle when turning.

[dj3nk]

Changed cabled to the core so I used the 2nd multiplexer for pots 1-8. The pots and the ain are working fine. Just the problem the other pots are moving with it. lookin aggain at the ain for that. but no chance to get the 2nd ain of the 18f working. dont know why. ill check if i connect it to the third and ground the 2nd. then setting pots to 24 should work or not ?

[dj3nk]

ok something on my lcd in going mad. but i see the pots are working now !!

changed pic to the old one, now works fine (old problem beginning of the thread lol)

think i shouldnt have heatened the solder without unplugging the pic.

[dj3nk]

GOT IT !!!!  Scratched with a nail around the soldering pads and it seems it was VERY LIGHTLY shortened.

hope i can fix the other problem with the ADC thing because it would be wasted saving space.

[dj3nk]

AAAAAAAAHHHH. But now I know what the prob was !

You HAVE to take the 3rd analog input of J5. i see, because i see reverb 9 on lcd when pot 9 is turned. my theory was itll get 17 when taking the 3rd analog input on the core.

I think this should be added to the ain page for others who only want to take 16 pots. A total newb would never find I think.