MobiFlight Community Support

Hi gents ,

I have a problem of LED out put using MAX7219.
I followed exactly your 7LED tutorial for COM1 display, however the output is weird.
My display module has VCC, DIO, RCLK, SCLK, GND....I put DIO pin22, RCLK pin 26, SCLK pin 24.
when I TEST , it shows PPPPP,
when running and adjust com1 frequency, it show some weird character instead of number characters.


Could you please advise that my display module is not supported or I plug the wrong pin?
Thanks.
Vu

here is a video showing my problem
https://youtu.be/1GnJZ05XB3U

Below is the chip i am using, I am not sure it is MAX7219 or not since it it has only 16 pins each.



Thanks

im not sure have max chip because my board have only one chip and you have 2 chip ?
have you test board mobiF tutorial setting ? must be working if have max chip.
https://drive.google.com/open?id=0B6fpBSKeeyqfM0VSYkxDS05IZDQ

this is my chip board i orden at banggood.com
http://www.banggood.com/MAX7219-Red-8-Bit-Digital-Tube-LED-Display-Module-For-Arduino-MCU-p-907849.html?rmmds=search
and this kit have good if need 1-8 digit (i use only 5 digit display) my radio/nav panel.
http://www.banggood.com/MAX7219-Dot-Matrix-Module-DIY-Kit-SCM-Control-Module-For-Arduino-p-72178.html?rmmds=search
this i orden my first 4 display now have
http://www.ebay.com/itm/1-2-5-10PCS-MAX7219-dot-matrix-module-Arduino-microcontroller-module-DIY-KIT-M67-/351873563233?var=&hash=item51ed4c7a61:m:m_8-IGAdWtKMaMhGsv0wVag
this i use before and working fine
http://www.ebay.com/itm/MAX7219-LED-Dot-matrix-8-Digit-Digital-Display-Control-Module-for-Arduino-/272279959978?hash=item3f652679aa:gQIAAOSwMNxXZ7Xj
this is pin assigment photo
https://drive.google.com/open?id=0B6fpBSKeeyqfOTR1eUpmZkswZk0
and maybe this help you too
https://drive.google.com/open?id=0B6fpBSKeeyqfX1RQLUlVVDE5NDA

Also you modules look very similar to the ones that are compatible with MobiFlight, your modules are NOT compatible.
They are based on a different chipset: TM74HC595

I am sorry. Make sure you buy the ones that say Max7219.

Thank guys,

Sure that I bought a wrong module,
I have ordered the other one and will update if it works.

Great!

Hi Sebastian,
I got 10 modules of Max7219 in hands.
However I am facing a very weird problem with Mobiflight.
I connect cable to mega pins as tutorial, the other side of cable I temporary hold to 7Led modules (without soldering) Com1 shown correctly.
After soldering, it does not work anymore, the module shown 88888888 all the time, the same problem with other 9 modules.
I test again on other computer with fresh installation of Mobiflight latest 7.3.1, other brand new Arduino Mega, check carefully the soldering, however it still shown 8888 (it appeared that DIN, CS and CLK pins are not connected)
I remove wires and connect directly the module to arduino, but it can not help.

The chip is MAX7219

Pin 22, 24, 26 are in used. VCC pin to 5V

It shown 8888 all the time, when Test Run or Stop.

Hi Master

2 Reasons are posible....

First a Software Crash ....

The Max7219 must be set to Arduino BEFORE you Start Mobilflight / Cause mobiflight send a "Startup Command" to the Display.... If you disconect one Cabel for example while Mobiflight is runnning the the 7 Segement can´t run again until you restart mobiflight ( And maby you have to disconect the Arduino so the Mega makes a restart too.
Basic Rule: Not Change Equpment on the Pins while Arduino is connected and/or Mobbiflight is active.

So simply connect youre Display.... Get youre USB from Arduino in and out.... Start Simulator.... Start Mobiflight..... Test ! Is it working ???

If Yes... problem Solved.... If Not..... Hardware Issue!

Harware Issue:

The Solder Pins from this cheap Chinese Boards are REAL delicate.
Alittle to long with the soldering Iron or to hot and the boards are killed.
Additional they got lots of woobleContact..... get shure you got a 100% perfect solder Point.... ( Use a verry thin solderiron and thin solder tin.)

Additional i see you got a seperate Grd wire... get shure this is contact good and is set to the same Arduino !

You try to weld the pins to LED first and use wires to connect to Arduino
I guest the welding is not firm enough, Bro

Thanks guys, i got the display module working fine now.
It just need to find the better socket to solder to the module