PE Lab - query on shifting LED display -IO&timing basics page 17
karli
Posts: 16
·· My Parallax Propeller apprenticeship is only going into week-2.
···I've done all the lab exercises to this point in that manual and all
·· spin routines worked fine but the ShiftRightP9toP9.spin has got
·· me stunned.·· I entered it· via F10 into RAM just like its printed
·· on page 17. but when I run it I see P9 flash and then P8 comes on
·· and stays on. I modified·· waitcnt(clkfreq + cnt) so I could see it
·· run slower.· I can do a manual· outa[noparse][[/noparse]9..4]·:= %100000·· entry
·· (with a repeat on the end)· and shift the P9..P4 bits· and each LED
·· turns on per each entry.
·· when I change the last line·· to >>= 3 and run the original code
·· I get P9 to blink and the· P6 stays·ON.
·· any pointers as to what's happening here ?
·· Thanks,
·····karli.
···I've done all the lab exercises to this point in that manual and all
·· spin routines worked fine but the ShiftRightP9toP9.spin has got
·· me stunned.·· I entered it· via F10 into RAM just like its printed
·· on page 17. but when I run it I see P9 flash and then P8 comes on
·· and stays on. I modified·· waitcnt(clkfreq + cnt) so I could see it
·· run slower.· I can do a manual· outa[noparse][[/noparse]9..4]·:= %100000·· entry
·· (with a repeat on the end)· and shift the P9..P4 bits· and each LED
·· turns on per each entry.
·· when I change the last line·· to >>= 3 and run the original code
·· I get P9 to blink and the· P6 stays·ON.
·· any pointers as to what's happening here ?
·· Thanks,
·····karli.
Comments
It's usually best to hand enter the code for the sake of letting it sink in as you type. However, to find out if there is a coding error, try the pre-written code that comes with the zipped lab. If the symptom persists even with the pre-written demo code, than move on to the circuit checking part that kuroneko suggested.
http://forums.parallax.com/showthread.php?p=617192
Andy
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Andy Lindsay
Education Department
Parallax, Inc.