MobiFlight Community Support

I made an EFIS panel for my a320 dev fbw. Everything works fine but i can't get my display to work. When i connect it to my arduino mega, it shows 8.8.8.8.8.8. I used the setting in mobiflight that i found on hubhop. (L:XMLVAR_Baro1_Mode) 2 > if{ 99 } els{ (L:XMLVAR_Baro_Selector_HPA_1,bool) ! if{ (A:KOHLSMAN SETTING HG, inHg) 100 * near } els{ (A:KOHLSMAN SETTING HG, mbar) near } }
When i push the test button the leds are dimming a little, but i don't get the 123456 value. The pins of my max 7219 are connected good, i have 5v, ground, and the din, cs and clk are connected to the pins 22,23, 24. Did i forgot something? Sometimes i read that i also have to use fsuipc for this? Any help would be welcome.

With regards,

Hi
You have definitly a electrical problem at first !
Displays who show 8888888 or flickering/change bright have a electrical issue !

To solve:

1. Get sure the display was connected to Arduino BEFORE you power the Arduino itself ( Plug in USB )
The Max Chip must get initialised at startup.
So if you try to connect it on a running Arduino, or if you stop connection and reconnect it while arduino is on.... this will not work.

2. Check all 5 Wires. Max7219 are verry sensible. So its high recommend to solder the connectors on the Tube and also to connect the wires directly to the Mega.
Not use Bradboards not use improvisional connectors.
At the end not get scarred. If the Max is solder corrrectly it will work fine all the time. Its just a one time work you must be verry accurate !

3. Check Power is ok.
Get sure your max got a own 5V power line ( not chained via a other max) and confirm your board is within the Limits.
Issues can also happen if you try to controll a lot of Motors, LED and so on with one Mega. If you overdrive the limit of power Displays also can get unstable.

Thanks a lot for your help. I rechecked everything and restarted. Now everything works fine.