MAX7219 - All LED turned on, no matter what i'm doing.

Using Arduino LEDs and Multiplexing
1

Hi there,

yesterday I soldered a 5x5 Matrix together and I'm using an MAX7219 to control it. I checked everything ~100 times :wink: but if i connect the Arduino all LEDs are turned on, no matter if I have some Code on the Arduino or not. Same happens if I only connect 5V and GND to the MAX7219.

I also used the forum search function but all I found was some unanswered threads from 2009. So I hope somebody can tell me what the problem could be or give some ideas how to find out what the problem is. :slight_smile:

2

My first guess would be you have all your LEDs backwards. Try swapping the Digit and Segment lines.

3

Ah yes, this was the problem :sweat_smile:
Thanks :slight_smile: