Hi, I'm planning to buy some of these 4 7-segments I've found: http://www.sparkfun.com/commerce/product_info.php?products_id=9483. I want to control them with a MAX7219 (I have some). The problem is that the displays are common anode, while the MAX7219 is supposed to work with common catode devices. I've thought about two possible solutions and I wish to know if there was any problem with them (my electronic theory is poor...). 1- Use of inverters at the digit pins. If I wire the digit pins to the digit pins of the displays throwgh inverters and I connect the segments pins in the usual way when I send a 0 the led will light and viceversa. So with the arduino I can easily invert the data send to the MAX7219. (Of course, I could use inverters for the segments too). 2- Connecting digits to segments an segments to digits. If I connect the pins of the MAX digits to the display segments and viceversa I'll maintain the right polarity. In that case when the MAX selects a digit, in my display it is actually selecting a concrete segment in every digit. So the transformation that I have to do in the Arduino is more complex, but I suppose it's possible.
I hope you can understand my poor english. So, do you think both solutions are correct? Will I have any problem? Wich one do you considere the best? Thanks in advance.