Max7219

RottenJalapeno

Does anyone know of an object floating around for the 8-digit 7segment display driver?· I tried using the BS2 functions object and using the shiftout to communicate with the chip, but for the life of me I'm not getting it to work.· PS I can get it to work just fine with my BS2...· Any help would be ausome, Thanks

Brian Smith

Ive tried the same thing and havent got anything to display.·The MAX7129·works fine on my BS2. Heres my code. Any suggestions?

Brian Smith

Well i fixed a few errors I thought I·had, but still no luck. I figured out that·I had to shiftout twice before loading the initialization stuff. Does anyone have any ideas why this wont work? Isnt anyone using the 7219 with the propeller?
Thanks,
Brian

T Chap

Try dira[noparse][[/noparse]18..20] := %111 instead of dira[noparse][[/noparse]18..20] := 1

Use the % followed by the number of pins( declaring the desired state of the pins) to alter on all instances of contiguous Dir assignments.

Post Edited (originator) : 3/12/2007 3:56:14 AM GMT

Martin Hebel

I'm not sure this is the problem, but you are missing BS2.Start(31,30). It sets up the timing values needed in performing operations.

-Martin

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StampPlot - GUI and Plotting, and XBee Wireless Adapters
Southern Illinois University Carbondale, Electronic Systems Technologies

Brian Smith

OK I tried these. But Im still getting all lights on. All 8s and decimals.

T Chap

Please post the modified code

Brian Smith

I rewired my breadboard just to make sure all connections were correct. Still no change.

T Chap

One thought that probably wont solve it... I don't have the BS2 objects, but is your Main program required to stay alive for the LED display to remain active?

Brian Smith

Im not exactly shure what you're asking. My program only has a "main" part so everything remains running... I think. Im not even sure that I need the BS2.Start(31,30). I think its only needed for things that use the com port (pin 30 and 31).

Martin Hebel

Yes, you need a BS2.Start. In there defines all the timing for things such as PULSOUT, SEROUT and many other functions.
Once it get's posted, an updated version will stress this in the documentation.

-Martin

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StampPlot - GUI and Plotting, and XBee Wireless Adapters
Southern Illinois University Carbondale, Electronic Systems Technologies

Thomas Stickney

I managed to wire up a workable circiut on the PPDB using the MAX-7219 chip.

Spin code is attached

Get BS2_functions from OBEX, Enjoy!

Post Edited (Thomas Stickney) : 12/2/2008 8:00:56 PM GMT

rogersyd

Works like a charm. Thanks Thomas.

Tip For the newbies dont skip the pin 18 to pin 19 resistor. I stared at the data-sheet for a good ten minutes scratching my head before i noticed this.

-rogersyd