MobiFlight Community Support

Hi,
I have 02 LED Max7219 modules and I want to connect them together but its not working
When I connect the 2nd module, it shows 88888888 and the 1st turn off (I connect 5 pins in the same order)
I tested individual module, so its ok

Pls show me how to connect 2 modules in a series or how can I fix that

Tks in advance!

Hi Toby
Welcome to Mobiflight !

At first look i will see 3 posible issues.....

1. Wrong Configuration.
I can´t see or understand with youre discription how you config the MaxTubes!
Please check and confirm you do the following way....
-Go to the Settings / Mobiflighboard Menu..... If you create a new Device "LED 7 Segment" you enter the Pin Numbers for DIN,CS and CLK . Riht of this fields is a additional Drop Down Menu called "NUM". HERE you define the number of Max7219 Tubes in a row.
So if you got a 2nd. Tube wired over the first tube ( a row) then you need a "2" in the num field. When finished not forget to UPLOAD the config and wait for the pop Up "Upload finished" .
- If you have tried to make a 2. Display Entry here in the past with the same Pin Numbers get shure you delete this wrong entry !

***********

2. Wire issue.
Get shure your wire-logic is correct First you have 5v and GRD from the Arduino to 1. Maxtube. Additional 3 Cable (DIN CS CLK) form the devined Pins on Arduino to the 1. Maxtube. All This need to wire to the Left Side. ( Where the label DIN is shown) .......
From the Right side ( Where DOUT is labeld) you have to wire 5 Cables to the next 2nd. Maxtube . Logic is the same.... 5V, GD and CLK workes same.
CS sometimes called LOAD here. Wire form CS/LOAD to the next Tube CS .... DOUT need to wire to DIN of the second Board. remeber to use the Input Pins of Tube2 (Left Side) .... You can buld this row up to 8 Maymodules !

*************

3. A Hardware Issue.
You told me you check youre tubes individual and they running fine as single Displays.....
Do you already test a changing of sequence ?
Does it work if you set Tube A to the Arduino and TubeB behind the first one ? If not change sequence Does it work if Tube B is in the Arduino and Tube A is wire to the outputs of the other one ??
If youre tube work individual as single setup i would say the INPUT Pins on the left are working fine..... BUT maby there is a solder Problem on the Right 5 Pin Output section.



Hope this helps and solve problem.
Please report experience and request more help if needed.

Thanks pizman82 for your reply
I will do again and again

I connect 5 pins on 1st to 2nd in a row (VCC-VCC, GND-GND, DOUT-DIN, CS-CS, CLK-CLK)
and config the number (in mine case is 02 modules) and select COM1 Active in NUM1, COM1 Standby in NUM2
Its not working on 2nd module

I will test as you said to make sure all pins OUT-IN is ok

Once again, tks for your help

Bad to hear first workaround not help,

Maby a tip....
Use "Test" Button in Config/Display Tab. ( NOT the Test Button at Main Menu.... And get shure Mobiflight is not Online (Playbutton) at this time )

With this test button youre Display should show 12345678 ( Or the number of Diggits you use and mark to active )

Do this Test for the First Config ( 1st Display Tube)
Do This test again for the Second Config ( 2nd Display Tube)

Doese this work and show correct values ??

At last ! Please confirm you run Mobiflight as Administrator..... You got current Version 7.2.3 ... AND Important. Tell me short what board you are using ( Mega or UNO ?)

Im using Arduino Mega 2560 with lastest Mobiflight v7.2.3
I will check about the weld, Im not professional with that
Anyway, I use 2 separate LED modules with rotary encoder and can change between Active-Standby radio freq .
It costs more module, more arduino pins but its works for me now

Can you show me the tutorial of precondition function? I still confuse about it. When i tune the Mhz and Mhz, only one can be tuned. Can I use push button to change tuning between Mhz to Ghz. Because I can not find dual rotary encoder in my place
Thanks so much!

Hi again Toby...

Hope you find the Problem. I cant see youre configs but if you do all you tell the problem must be 99% in the hardware.....
I see you got the basic Max7219 with blue PCB form china. I got the same and 5 of my 8 tubes i ordered got demaged Pins ( Some on the Input some on th Output line ). Maby a problem of these 3$ Cheap elements.

To youre request.....
Yes i´ts posible to use the button of youre encoder to switch between KhZ and MhZ. You need to use a Custom Offset and a precondition for this.

Sorry, that the "turtorial" for this is not avalible now. i work on it but as i told in other threads... This will take a longer time. Not wait for this in the next weeks/months. Got lot´s of other stuff on my to do list.... apology for that.

I just explaned this technic in some threads here.... Search the forum please ! (Maby it´sin german section)

In short words...
Create a Input and use a custom offset .... For example 66C0 I Byte.
Set this Config to the Push Button on youre Encoder
Set ON PRESS value : if($=0,1,0) // This will toggle the value of 66C0 everytime you push the button between 0/1

Now Create a Output Config ( No device ) and READOUT the status of Offset 66C0. ( This is only used for our precondition later) Name Of Config for example " Read Button"

Then Create 2 Input Configs for youre encoder.... One with On Left On Right for KhZ ...... The Second One with MhZ configuration.
Now set on every Encoder Input Config a Preconditon....
For One Config you say "Only work if Value of Config "Read Button" = 1
For the Other encoder Config you say opposit ... Only work if Value of Config "Read Button" = 0

So.... If you Push the Button the Value of Custom offset toggel 0 or 1 ..... And youre Encoder sets Khz or Mhz depending on witch is the status of the Read Button Offset.

Hope you understand this short manual.... If not just ask... then i will give you a better guide again !

Hi there Tobypham, check following.















1. Save Config
2. Close Mobiflight
3. Disconnect Arduino
4. Reconnect Arduino
5. Open Mobiflight
6. Open FSX
7. Click Run

It should work
AlbEagle

To: pizman82
You're right man. The weld is not firm enough. I got it. tks so much

To: albeagle
Im following your tutorial making C172 and waiting more and more. tks man