Yet again, thanks Steve for continuing to offer your help!
I will have to see if I can get someone in my university's electrical engineering department to allow me to use an oscilloscope.
I suspect you are right that the problem I am seeing has something to do with the MAX7219 acting as current driver/sink and how that current is interacting with the transistors in the 2803 is the issue here.
I have also ordered the transistors needed to test the circuits described in the MAX7219 technical note about driving higher voltage & current led arrays: http://www.maxim-ic.com/app-notes/index.mvp/id/1196. Maybe this will solve my ghosting problem, though it means I will be using individual transistors rather than 8 channel ICs for each digit and each segment circuit.
I will have to see if I can get someone in my university's electrical engineering department to allow me to use an oscilloscope.
I suspect you are right that the problem I am seeing has something to do with the MAX7219 acting as current driver/sink and how that current is interacting with the transistors in the 2803 is the issue here.
I have also ordered the transistors needed to test the circuits described in the MAX7219 technical note about driving higher voltage & current led arrays: http://www.maxim-ic.com/app-notes/index.mvp/id/1196. Maybe this will solve my ghosting problem, though it means I will be using individual transistors rather than 8 channel ICs for each digit and each segment circuit.
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