7 segment LED display gets crazy and then just tunrs off

[tranquil maple]

hi guys,I have a problem, I was trying to start to built a radio panel with a couple 7 segment led displays, I made the connection with mobiflight, it shows the frequencies as it has to, it works very well, the solder are fine also, i think, (i made my best).... but when I move the radio frequency knob three or four times the 7 segment led display gets crazy and then turns off 😦 anyone knows where could be the problem?

I have only one 7 segment led display connected to the arduino and I have it connected to an USB hub that is connected via USB to the PC and powered to the current with the power supply cable

if the problem is that I should connect the arduino direct to the current (not to the powered USB hub) (I havent tried this yet) will I need to connect the other 3 led displays to built the radio panel and will I need 4 arduino and 4 power supply cable by separated?

i Also tried to connect it direct to the USB port of the PC

will add some photos and videos

I hope someone can help me 🙏 I will appreciate it

I use MSFS2020 and i want to make the 7 segment LED displays works well when I rapidly move the radio tuning knobs, I have the latest version of mobiflight and im using an arduino MEGA

(im sorry English is not my native language)

[worldly panther]

Something that's worth trying straight away is putting that purple wire to GND on the arduino, not one of the data pins. Can you share your mobiflight device config too?

[peak barn]

Those last two pins of the dual row connector after pins 52 and 53 are GND.

Usually MAX7219 issues are one of three things

• bad modules (there are lots of cheap max7219 produced with very cheap price, the pressure to cut corners in cost is high
• bad wiring or soldering- the cheap DuPont cables used for prototyping boards can be quite prone to disconnects and the MAX7219 does not like that. Also bad or cold solder joints can be a problem.
• power supply being inadequate. While a single MAX7219 should work ok from the USB power, you should use a powered usb hub, and not daisy chain the power if you connect several modules in a chain.

One easy way to check if the problem is related to power is to reduce the global brightness in the pin configuration to the lowest setting and checking if the module works better.

[worldly panther]

I run 2 x 6 digit .28" 7 segment units from a mega 2560 pro mini without additional power... are you absolutely sure you've got the connections the right way round to the config in mobiflight?

Do you have another display unit you could try?