MobiFlight Community Support

Everything works, I have 2x 7 segment displays connected for the flight and landing altitude in my PMDG 737, everything was working until today, I start it and it displays until I turn the FLT dial and the LED just turns off to a blank screen? - just 1 screen the other remains on and operational?

Am i missing something here or is there a glitch with PMDG?, thanks!,

I have removed all other devices to test and same thing happens, I have even tried other displays and wiring, the output is correct onthe FSUIPC output value?

what am i missing here? help.....

thanks, Steve

Hi Steve,

what happens to the display in the simulator? Is that exactly how it is external?
If not, check the wiring. When the wiring is up and running, check the test button in the wizard. The sequence 12345678 must be displayed here if you have assigned 8 digits. Otherwise correspondingly less.
What kind of encoder did you connect how? Are the cable connections ok and, above all, correctly connected. You may be shorting out when you turn the encoder. Do you use pull up resistors for the encoder - these are often recommended according to the data sheet, but are not required with MobiFlight.

Errors in this regard are not known to either MobiFlight or PMDG. The most common errors are in the connection or the wiring.
Please check this information in your circuit and report the result here.

Hi, I have nothing else attached to the Arduino except the 2 LED 7 segment 8 digit displays, the rotary is off of a leo bodnar board so not related to this issue.

The pins are the standard type and brand new so shouldn’t be an issue, i moved to pins 22, 24, 26 and now it works so maybe there is an issue with some of the board sockets.....very odd as they are almost new, I’ll keep an eye on it and report back.

Thanks!

Hi

Like always... "Sherlock Holmes Methode" !!
I don´t think your pins on the Mega was broke ( verry rare issue) .

Are your Diplays already perfect solder or is this a testing ground with Jumper wires ?
Max7219 are "verry" sensetive .... especialy if not solder.
I personaly think the reseting to the other Pins simply solve a little loose wire problem. Normaly just moving the wires a little bit ( without change Pins and device setting) would result same way.

For the next time.... Make a simple test like stephan say. Use in the problematic Config the TEST Button on Display Tab. If display show correctly 12345678 then you 99,9% know its a software issue..... If it not show data it is a hardware issue pretty sure !

Thankas!, yes all the pins are soldered to the display!, and the pincs connected to the arduino mega are the STD arduino pins so not really a loose connection..

Maybe its the ELEGOO board vs an original one, ill monitor and worst upgrade to a proper one!

thanks

Speaking for experience with MAX7219 tubes from Amazon you have to test every single one carefully before attempting to wire them in series. Out of 10 tubes I got from Amazon one was defective and caused me hours and hours of grief. Also the diodes that come on the tube cause issues.

If you plan on using these I strongly recommend removing the diode and replacing it with a small piece of wire. It takes no time at all to do and makes these actually usable in a daisy chain situation: I have six connected in series with the diode removed and they work great.

I strongly recommend methodically testing each board upon arrival as well to save yourself a TON of heartache trying to figure out why things aren't working. Remove the diodes on all the boards and then:

1. Test every board in isolation to ensure it displays properly. Mark the "in" end of each board as OK.
2. Take a board with a known good "in" and use it as the second board in a daisy chain. Test every board as the first board and verify both boards light up correctly. If this works then mark the "out" of each board as OK.

In my case I had one board that didn't work properly for "out", and regardless of where it was in chain it would cause havoc with the other boards.

Thanks, what sort of issues? as 1 out of 4 *(2 on each board to minimize load) acts odd, the other 3 displays are working fine and this one for the IRS will display for 5 mins and then start displaying random numbers / letters or the brightness will suddenly increase to max...is this the making of a bad tube?

thanks, Steve

Yes, any and all of those issues could be a bad tube. It is really important that you methodically test each tube, and if you are daisy chaining them remove the diode, before attempting to do anything fancy with mobiflight. You will save yourself a TON of pain.

thanks, im not daisy chaining them, i simply have 2 hooked up for IRS left and right, and for some reason the right one e.g. W000099, works fine then shuts off, or goes bright and then shuts off?, ive even tried swapping the with the other 7 segment and the same thing happens...so it must be some signal or setup that is interfering...very odd as no issues with the other LED display whatsoever...ahhhhh, everything is soldered and pinned!, maybe an issue with the PMDG offset but the FSUIPC display is always correct!

Have you removed the diodes? Have you methodically tested every tube in a simple setup?

If the answer to either of those questions is no then you are wasting your time trying to guess what is wrong. The tubes are extremely touchy.

Get rid of the diodes to eliminate them as the cause of your issues. Test every tube individually with no other tubes attached to your breadboard in any way.

OK, Diodes removed tubes tested...same issue with IRS...

I switch to say battery output on both displays and its perfectly fine....is there a possibility it goes crazy when not able to display say W for example, thats in the FSUIPC and outout values...

I might have to forgo the IRS as its just related to these displays only!, everything else works fine...

thanks!