SSC-32 input problem

[dark]

Hi guys,

i think i need some help on my inputs wiring…
as ive no idea of whats going on there

here a pic of my setup

the pot w/o knob is connected to the input A

the multiplexer is connected on the pin 28, 29, 30, 31
and is not connected in the inputs

the pot with the knob is connected on channel 1 of the multiplexer

if i connect the pot alone, it work fine

if i connect the multiplexer alone, it work fine

now if i connect the pot on the input A, and then connect the mutliplexer into the power supply and the input pin(s0 to s3) on the ssc32
the value on the pot(input A) change

and if i add the pot on the multiplexer
then the value on the input A and multiplexer goes to 0

someone know whats wrong with my setup?

ive tested 2 different voltage regulator just to be sure, but result were the same.

[dark]

eh… nvm… it work now

not sure exactly what was the problem…
but i get values now with everything connected

[zoomkat]

Floating control pins on multiplexing chips can cause issues.

[dark]

well… i think i really need help with the wiring after all

i was doing some tests and the voltage regulator didnt light up…

so i decided to use the other VR, connected everything, led on the VR and the SSC32 was lit

was doing some querries on the inputs, in lynxterm with the official firmware.
then all of a suddent it did smell burned electronic.
quickly disconnected everything and found out the multiplexer was burning hot :S

not sure the mutliplexer is still functional or not but i fear that i will end up with a toasted ssc-32 if i keep playing with the inputs

ive put back the pics, maybe someone can see some obvious error in my wiring?

at some point i thought my firmware was the problem so i went back to the official firmware
but the result is the same…

if i would not be stuck on this inputs nightmare, the beta version of my firmware would be released already
was going to do more tests on the inputs and this all started when ive tryed to connect more than 1 input on the ssc-32

[robotdude]

The images are of no help. They are too far back and you can’t see what is connected to what. Can you draw up a schematic or take a closer picture?

[dark]

here a better pic

the wiring is pretty simple and straight foward

1 pot is connected to VR, sweeper and ground to the input A on the ssc32

multiplexer’s vcc/gnd connected to the VR, sig/en connected to input C on the ssc32
s0 to s3 connected to the ssc32 output pin 28, 29, 30, 31

other pot is conected to the VR and the sweeper to the channel 1 on the multiplexer

[dark]

i think ive finaly figured whats going on there and why my multiplexer burned when i tryed the official firmware and lynxterm

i made a new test with the official firmware and lynxterm

ive connected the battery and checked the inputs voltage

on the official firmware the inputs are configured in latch mode by default.
and that is what i read on the pins

input A: +5v
input B: +5v
input C: +5v
input D: +5v

then i pressed VA, VB, VC, VD 2 time to set them in analog mode and get a value
now the pins read

input A: +5v
input B: 0v
input C: +5v
input D: 0v

i dont think i should have +5v on the inputs!?!?

now the fact that the multiplexer as only burned when i performed a test with the official firmware and lynxterm is due to my multiplexer support.
since my firmware did switch the channel internaly, it did only short the mux 1/16 of the time…
when i did the test with the official firmware, the chan was locked on the channel 1 which shorted it totaly

but what i still dont understand is why it only happend when input A and C are use, things work fine if i use only 1 input

im totaly lost now… heh :S

[zoomkat]

now the fact that the multiplexer as only burned when i performed a test with the official firmware and lynxterm is due to my multiplexer support.

Well, when you start flashing firmware and doing your own wiring, anything is possible. I tested the ssc-32 with a 74hc4051 multiplex chip and had no issues beyond what appeared to be floating control pins. If something gets hot, most likely you have a short/bad wiring.

[dark]

oh… i didnt mean that the official firmware did cause the short in my multiplexer… sorry if did sound like that
it as nothing to do with the firmwares

i know my wiring is wrong, thats actualy why i asked some help in the first place
im a noob with electronic… can hardly wire a led w/o blowing it up…

tought the +5v on the inputs could have been the problem, as i didnt expect to see any voltage there…
but after testing the ssc-32 in my hex(never used the inputs on this ssc32) the voltage reading on the inputs was the same
so i know this is not the problem.

so… if my wiring is wrong, how it should be wired?

[dark]

bump

hello?

this forum as over 5000 members
i would be very surprised that no one know how to wire the ssc32 inputs!?!

really appreciate Zoomkat’s reply, but this doesnt help at all…

it as nothing to do with floating pins
nor with the firmwares

totaly sure that ive no shortcut in my wiring

pot alone, work as expected
multiplexer alone, work as expected…

why i cannot get them to work properly when both are connected?

technical support would be appriciated

thank you

[robotdude]

@"[Dark

"]this forum as over 5000 members…

… technical support would be appriciated

How about posting the schematic I asked for… Your post has been viewed 155 times. It’s not that no one is looking… You are not providing enough information…

[zoomkat]

why i cannot get them to work properly when both are connected?

Since you have ruled everything else out, then most likely you have them connected incorrectly. You haven’t bothered to tell what multiplex board you are using, but looks like the sparkfun 4067 based one. Have you looked at the data sheet for the 4067 chip to check your wiring connections?

[dark]

@Robot Dude

How about posting the schematic I asked for… Your post has been viewed 155 times. It’s not that no one is looking… You are not providing enough information…

you asked for either a schematic or a better pic, ive choosen the pic because the wiring is very simple
schematic in this case would be irrevalent and i think ive provided more than enough information about the wiring and behavior of the setup

what other info you would like to know?

@zoomkat

Since you have ruled everything else out, then most likely you have them connected incorrectly. You haven’t bothered to tell what multiplex board you are using, but looks like the sparkfun 4067 based one. Have you looked at the data sheet for the 4067 chip to check your wiring connections?

yes i have checked the datasheet for the chip and the documentation for the breakboard

anyways… ive taken the multiplexer out of the equation, and found out some more “interesting” results

ive tryed a new setup using only 1 power supply
connected only 1 pot and the pot get shorted or something and heated up

the same setup, using separate power supply for the ssc32 and the input work fine

which bring me back to the time when ive checked the voltage on the input pins when configured as analog…
the result were

input A: +5v
input B: 0v
input C: +5V
input D: 0v

now… obviously, if the input pin does output voltage… something must be wrong!?

and if the input B and D show 0v, we could expect that the 2 setup shown in the pics would work… and it does

but if connected to input A or C which as +5v, the separate power supply setup work, but the single PS setup short the “sensor”

so… the whole problem seem to come from the ssc32, not my wiring

really need that LM enlighten me on whats going on with these inputs

i need some explaination about these voltage reading on the inputs pins

why input A and C show +5v and B D show 0v on my 2 SSC-32?

[zoomkat]

which bring me back to the time when ive checked the voltage on the input pins when configured as analog…
the result were

input A: +5v
input B: 0v
input C: +5V
input D: 0v

now… obviously, if the input pin does output voltage… something must be wrong!?

Well, you may be screwed up on which pins are which on the ssc-32, or possibly you are trying to measure voltage between the input pins and the adjacent pins which are +5v, -ground, +5v, and -ground with a multimeter. The board comes from lynxmotion with jumpers across these pins such that input pin A is connected to +5v, pin B is connected to ground, pin C is connected to +5v, and pin D is connected to ground. You might try reinstalling the jumpers to see this in action and see the voltage values returned. Bottom line, the board works the way it is wired. If you have components getting hot, you really need to recheck your wiring. if you are going to provide useful pix, you need to put the cam in macro mode so connection to individual pins can be seen.

Edit: just squinting at your pix, the yellow/black wired between the pot and ssc-32 appear to be fliped, which could explain why the pot got hot. The center tap of the pot goes to the A pin. The outside taps of the pot need to go to +5v and -ground. For a quick test assuming the pot red wire is connected to +5v, move the black/yellow wire to the B pin with the yellow connected to the B pin and the black connected to the adjacent - ground.

[robotdude]

@[Dark] I hopefully will shed some [Light] on your problems… First off the inputs all have 5vdc on them. The inputs have pull up resistors so if nothing is connected they will and should measure 5vdc. But they all measure 5vdc. Your issue is you are not using a common ground. Or you are not measuring the inputs from the reference of ground.

The input header on the SSC-32 has 2 x 5vdc outputs, 2 x ground connections, and 4 x inputs. Connect the 5vdc to one end of the pot, connect the other end to the ground, and connect the middle wiper to the input. When utilizing analog inputs it’s really best to use the same supply as the processor. This is covered in the SSC-32 manual.
lynxmotion.com/s-4-electroni … .aspx#serv

Specifically in this diagram. Second column third row.

[robotdude]

@zoomkat

…if you are going to provide useful pix, you need to put the cam in macro mode so connection to individual pins can be seen.

Edit: just squinting at your pix…

If you click on the image twice it becomes rather large.

[robotdude]

My apologies to [Dark] as I also didn’t think to try clicking on then images. I could have solved this with the second image actually.

[dark]

@Robot Dude

The input header on the SSC-32 has 2 x 5vdc outputs, 2 x ground connections, and 4 x inputs.

now that make sense and also explain the weird behavior i was getting.
i assumed the inputs was 4 input pin and 4 ground pin.

there are no mention of that in the pdf about the +5v output pins though…

well… i guess this solve the mystery about my input problems

thank you Zoomkat and Robot Dude.

really appreciated!

[robotdude]

@"[Dark

"]

@Robot Dude

The input header on the SSC-32 has 2 x 5vdc outputs, 2 x ground connections, and 4 x inputs.

now that make sense and also explain the weird behavior i was getting.
i assumed the inputs was 4 input pin and 4 ground pin.

there are no mention of that in the pdf about the +5v output pins though…

We’ve just updated the SSC-32 manual. It has the information now.

[zoomkat]

If you click on the image twice it becomes rather large

That’s what I discovered that allowed me to go back and edit my post.