Driving a 7Seg three digit common anode display

[Andres Rodriguez]

Does anybody have experience driving a 7Seg common anode display with a MAX7219.
I would appreciate any input on the subject.

 

[Pongo]

I've had great success using them with a picaxe, but as you surely know the MAX7219 is a common-cathode display driver. As such it would need significant external circuitry to drive a common-anode display. If you can't get an equivalent c-c display then I suggest you choose a different driver chip.

 

[westaust55]

I have used the 7219 with CC displays but no experience with CA displays.

While the MAX7219 is intended for Common Cathode displays there are some websites with information on using C-A displays including:
http://marco-difeo.de/2013/02/21/drive-max7219max7221-with-common-anode-displays/
http://forum.allaboutcircuits.com/threads/max7219-common-anode.95545/

Maybe indicate why you specifically want the nominated combo and where you think help is required.

 

[hippy]

The MAX7219 is an 8 digit 7-seg+DP driver but can also be used as an 8 x 8 (64) LED driver. When used in LED mode the internal 'digit decoding' has to be disabled, the data then sent is raw pixel data for the 64 LED's.

7-seg+DP common anode displays can be connected; that's just the same as an 8 x 8 (64) LED display using segments instead of LED's. All you need to do is figure out which pixel data bit sets which segment, have your number display routine decode the numbers, set the bits and pass them on for display.

I know this has been discussed on the forum before, but not sure where, and not sure if there is any example code.