MAX7210 Display Warning

Sometimes I surprise myself with how stupid I am. And sometimes I surprise myself with how clever I am. These events seem to level out, which I suppose makes me a balanced kind of a person.

Anyhoo, today was one of the latter occasions. I’d bought some more MAX7210 displays from Amazon and today I wired them up and put them in little boxes. One worked fine, but the other was very broken. The display was corrupted and didn’t seem to respond to the microcontroller.

I took a proper look at the board and discovered that the input connector had been soldered to the output end of the board. These boards are designed to be chained together to make long displays. Normally the output is not connected.

I dug out a replacement connector and soldered it into place. And then the display still didn’t work. Wah. Then it occurred to me that if the connector was in the wrong place it might be that the whole board had been assembled upside down. This meant that the led arrays would have been fitted the wrong way up. I flipped them over and they worked. Go me!

Of course a super intelligent Rob would have checked the board before he put the devices together. I’m sure that’s what you’d do, dear reader. But I’m still a bit pleased with myself for getting it to work.