Large number of flickering/ghost inputs on Master Cards

[Boeing 747 Flyer]

Hi Les,

Each of the 5V power supplies I used for the master card were slightly different in terms of their ratings:

* 5V, 2.25A
* 5V, 2.25A
* 5V, 4.00A
* 5V, 1.00A

I'll get that PSU ordered ASAP.

One thing I am worried about is that the flickering does NOT occur unless there is actually an input IDC connected to the master card block. Without this, even with ALL ON commanded, no flickering. Could this too be explained by the lack of a suitable PSU?

On another note, do you know what the voltage levels are for an OFF/ON command in SIOC? I'd like to do some more work with my oscilloscope.

EDIT: PSU has been ordered! Should be here within a week. Anything else I could be doing in the meantime?

Thanks very much for your help Les (& David/Hans!!!)

[iwik]

Jack,
The trouble i have at the moment is knowing what your setup looks like. For example, how many 7 segment displays,
how many leds.
Yes it puzzles me re idc on input.
Lets summarize what we should be doing.
1. P/S needs to be large enough to supply enough Current. Amount of current will depend upon quantity of
7 Segment displays and LEDs and Relays you are driving from M/C and Display Card outputs.
2. Wiring needs to be kept separate, outputs and inputs, especially when 7 Segment dispalys are used.
3. You need to test your system starting with USB Exp-1 M/C,1 display and cable connected to inputs on the one
M/C. This cable should not be the one that is connected to all your switches. This is just in case your input
wiring may be somehow connected to something else it shouldn't be.

You say removing the input cable stops the flickering. This indicates to me that maybe you have some
cross coupling or a connection that should not be there. The best way to check this is to do what I suggested
in 3 above.

So here is what I want you to do:
Have just the 1 M/C,USB EXP card and 1 Display card connected with the 4amp p/s.
Hook up an idc cable to the inputs that you currently have problems with.
This setup should ideally be on the bench. What worries me is the piles of wire
you have criss crossing your modules which could be introducing noise. As you said removing
the input cables the flickering stops.
What we are trying to do is keep everything clear of your existing setup.
This will check your modules are all ok.
Les

P.S I have had funny things with inputs when I have forgotten to switch on my 5v supply
to my m/c so the P/S is very important.

I have sent u a PM.

[Boeing 747 Flyer]

Hi Les,

Test carried out as per your instructions.

I can indeed confirm that with an open-ended IDC cable connected (one end into master and other not connected to anything), there is no flickering of inputs, no matter how many times ON/OFF is commanded. Moving the IDC cable close to the 7-segment displays units or outputs doesn't make any difference on SIOC monitor. 4A power supply is connected.

This might indeed be a wiring problem after all.

[iwik]

Jack,
That's great, now take one of the input terminating boards and plug in the cable , hopefully your problem will return.
Suggest lifting this terminating board and moving physically or disconnect each wire one by one to see if it's any particular one that's causing your problem.
Please keep us posted on progress. You will beat it Jack.
Les

[Boeing 747 Flyer]

Hi Les,

Yes indeed, after plugging the IDC connected to the input board back in, the problems have returned. My concern here is that I will have to unplug every single input and rewire the whole thing, it has taken years to get to this exact stage and I'm just not sure I'd even have the time to put it all back together again!

I will await the arrival of the power supply; perhaps that can give a smoother output which will reduce the magnitude of said interference... If not, I guess we will have to start rewiring it, I suppose it will have to be done in the end anyway if it's the only solution.

Thanks very, very much for your assistance Les, I will certainly keep you posted. I'll do some more generic messing about tomorrow and report what I find.

On another note, I did some google searching and found this thread, you may wish to take a look:

http://www.opencockpits.com/index.ph...-card-and-sioc



Jack

[iwik]

Jack,
If you have been at this for years when did the Lights test give u grief. Were the displays the last to be added.
It may not be as big a job as you think, see which termination board of inputs give the most interference and this might lead you somewhere closer to where the problem lies. Good Luck
You are not alone here I have times when I finally add something and it breaks something else. That's the name of
the game with DIY. If the P/S doesn't fix it then check if all termination boards do a
similar thing when plugged in one at a time. If so try to look for something that may be common to all inputs boards.
Les

[Boeing 747 Flyer]

Hi Les,

I have spent about 4 hours working on the cockpit today doing random testing. PSU hasn't arrived yet, but I have made some *very* interesting developments.

* The flickering inputs are always connected to the input block J3 on the master cards. Even if I swap all of the IDC cables around, the flickering will always occur on J3. The nature of the inputs connected to J3 does not matter However, when nothing is connected to J3, no flickering occurs.

* No matter how many times ALL ON/OFF is commanded, there is no flickering whatsoever associated with the inputs connected to J4. If I connect an IDC block that was previously flickering when connected to J3, upon being connected to J4, the flickering instantly stops. Furthermore, this happens no matter which master card I use; the problem occurs on J3 on all four master cards.

* Sometimes when I flick a switch, two inputs are activated at once. The "secondary" input that is activated upon a switch flick is always an input on the bottom row of SIOC monitor.

Is there anything special about the construction of J3 that makes it more susceptible to interference?

Jack

[fordgt40]

Jack

I have have a spare expansion board I can lend you to swop over and see if that solves the problem

David

[iwik]

Jack,
What happens if you unplug your displays, not the display card. Does J3 inputs still play up. Cant explain why J3
will only give you problems. Maybe O/C can tell you this. Email sales for a possible answer.
When you connect to j3 what's on the end of the cable is it still your panel switches.. You told me earlier that a idc cable connected here with nothing connected to the end of it gave you no flickering. Their maybe something about there
layout and you feeding it with your layout of wiring produces what you get.
Why don't you take the unconnected idc lead plugged into j3 that gives no flickering and command a ALL ON the
place this cable in the approx. pyhsical locality of the input cable from you switches and then see if they flicker.
Les

[Boeing 747 Flyer]

Hi Les,

That's correct, an IDC cable with nothing connected to the other end produces no flickering either way. BUT, with the input IDC cable connected to my switches, flickering only occurs with J3, not if I connect that same cable to J4. This I cannot understand since there is nothing special like J3; per your advice yesterday the master is no separate from the lot so there is nothing in the locality of J3 that could cause any problems whatsoever.

I have tried plugging an open-ended IDC cable into J3 and waving it near the input/output wiring; nothing whatsoever happens on SIOC monitor. Furthermore, unplugging the displays but leaving the displays card in makes no difference, still the exact same flickering pattern.

Having done even more fiddling about with wires and swapping things around, I must again confirm that it is only ever the inputs associated with J3 on each master card that has the flickering problem.

I am liaising with Alejandro from Opencockpits' support on the matter, he has asked me to photograph all four of my master cards (both sides) and send them to him; I shall do that now and I will also post the photos on here should you wish to see.

@David: If you could, that'd be fantastic, very kind of you to offer! If the same problems occur with your board then we can at least rule out the USBExpansion at fault.

Cheers,

Jack

EDIT: We'll have to wait for the photos... As if my luck could get any worse at this moment!!! My digital camera has given up the ghost (will not even turn on after charge).