MobiFlight Community Support

Hello friends:

I have finished with the complete project of Radio Panel for Cessna 172 totally made with Mobiflight.

Easy configuration and pleasant and fantastic result. Very good support in the forum, especially by Pizman82, StephanHo and Sebastian.

In general, everything works correctly, except when: I run/stop simulation in configuration mode without closing the application. There, sometimes it does not reset the displays of 7 segments correctly, in a somewhat random way. But if I close the application completely and run it again, it works correctly as long as it does not stop/run the simulation.
But that only happens while you configure and program your configuration, therefore it does not have the slightest importance, because once the configuration are finished and autorun MB everything works correctly, as expected. Perfect.

However, I have a problem, that I have more than 15 days without being able to fix and that after reviewing all the hardware, and everything is correct, I can not find an explanation, but it could be an erratic conduct of MB or an error mine in the hardware/configuration that I can not find.

I am trying to implement a more real conduct of the Radio Panel.

I want that when the master battery or avionics switch is OFF, the radio is OFF as in reality (really in MB it does not show anything in the displays, LEDs and lcd display is enough).

I started with the 8 outputs corresponding to the Comm and Nav frequencies, to implement a shutdown control.

I have created new 8 BLANK outputs for each of the 8 frequencies, and also those of the two battery and avionics master switches (as preconditions use).

I have followed examples that have been put on the forum by StephanHo and other gurus.

And it works erratically. I can not find an explanation for the behavior.

I thought it could be a problem of power, in the power of USB ports were not enough for the consumption of amps to serve the entire radio.

I have used a self-powered USB hub of up to 5A, but with the same result.

I have made a video with explanations, where you can see the normal behavior and the anomalous behavior when I try to use the preconditions to show or not certain data in displays.

http://www.ec-cts.com/images/ERROR.mov

I also put a link to the .MFMC configurations of the two arduino, as well as the MCC configuration (the mcc file is too long to put it here).

http://www.ec-cts.com/images/Arduino-MB-01.mfmc
http://www.ec-cts.com/images/Arduino-MB-02.mfmc
http://www.ec-cts.com/images/RadioPanelCessna172Version9.mcc

Can you tell me what I'm doing wrong?

Thank you in advance for your help.

Regards

Carlos (ec-cts)

Hello Carlos,

Currently, pizman is on a well deserved vacation and is recovering from the many work. This is usually his profession. But I want to try with my modest knowledge to get you on a possible path.

I think you have to set the conditions for turning the displays on and off over preconditions.

For the battery master you use offset 0x281c (1 = on, 0 = off)

For the Avionics master, you use offset 0x3101 (1 = on, 0 = off) [read for the status, write to control]

Condition: if Battery-Master = on AND Avionics = on then switch display to ($) else display off (_ _ _ _ _- 5 x space)

So if one of the two conditions is NOT met, the displays will stay off (actually being written with space keys). Even if only the Avionics Master is ON, but the Battery Master is OFF (or vice versa), the displays will be dark.

So you have to incorporate these two preconditions into the configurations in which they should work. For this I would first start with a config until it works satisfactorily and then transfer this to the others.

The fact that your displays remain arbitrary is due to the fact that they are addressed serially. If you switch off MF, the serial data supply of the displays abruptly stops and the MAX chips then partially retain their memory values ​​because they no longer receive the switch-off impulse from MF. They are still waiting for data. It would be necessary to examine to what extent Sebastian is able to check this and call a corresponding routine before switching off MF. Basically, I would not call this an error of MF, rather than blemish.
Why at the restart not all displays again show their current values, I can only guess, but should also not happen. In this respect, Sebastian would be called here to say something.

I hope I could help you.

Hi Sthepan:

Thanks for your fast response.

I have made the conditions as you indicate.
In fact, I followed yours indications of a previous post (with download example), in which you put a very similar example and I have done the same, trying only with the radios comm and nav, and once I achieve that they work correctly, I extend the rest of the radios .

I believe that it is a problem with the data management of the max, which retain or block data even when disconnected from the MB, and it is very possible that when the 8 tubes of displays of the comm and nav radios are chained, do not reseteen duly.

The problem is that I do not know how to really fix it because the configuration of the conditions works correctly, but then as you have seen in the video, it does not clean or reset the operation of the max.

I'm going to see if there are any free pins left in the arduino and I can make a new display line and then split the line of 8 tubes displays chained to 4 and 4.

Meanwhile, I wait for Sebastian's imagination to see if he is able to tell me something when he has time.

Cheers and thank you again.

Carlos (ec-cts)

Hi Carlos,

I wrote to Sebastian separately and asked him to take care of your problem. I think he will contact you.

Thank you very much StephanHo.

Regards

Carlos (ec-cts)

Hi guys...
I just overview that.... But i think i need a bit more time for that,

Thank you for the Video.... But PLEASE. Make it with sound next time ( Whatever you speak spanish.... Just try to say important parts in english )
It´s a bit confusing to just see what you do all the time... If you "tell" it to me i know before what i need to look in next step..... Without that information i must repeat every situation 2-3 times to understand WHAT you do now.

I will try to figure out this next days ! ( If possible let the Files alive until next week !)

Hi Carlos,

I have connected my panel, which consists of 14 displays of 5 digits each. Each display is connected to a MAX7219 board. These 14 MAX boards I have joined together to form two chains with 8 and 6 boards.
Both chains are running perfectly.
Now that you've described your problem, I've been paying special attention to the displays and would like to share my observations with you.

First of all, I have to say that my assumptions, which I made above (serial control with an obvious timing problem), can not stand this way.

Unfortunately, I have no video camera to show you the result, but I can tell you.

After MF was started and also the FSX is running, also MF was started. Now, as you have shown in your video, I pressed the stop button at MF. The displays now showed that they were also shut down in the order they were configured in MF before MF shut down. After a restart by means of the start button, the displays switched on again in the same order.

I was able to repeat this several times, even after a complete restart of MF and the same interplay. However, I could not observe the effect you showed. I assume that this is also the approach of MF intended by Sebastian. In that sense, the behavior of your circuit is not explained to me.

Maybe something else about my design: I have removed the diode D1 on all MAX7219 boards and replaced it with a wire bridge. Likewise the 10 KOhm resistance (exchanged with 40 kOhm). Then I looped through all 5 lines in the chain from the 1st to the 8th (or 6th) board. Also, all solder pads were re-soldered. The original displays (red) have been removed (plug-in version). Then I connected 5-digit displays (white) with 13 cables each. I have soldered the cables to the sockets of the boards.

So now both chains are running with me and I'm very satisfied with that.

I hope these hints will help you.