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here is my problem...

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Newbie level 5
Dec 28, 2005
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Hi hi!
Sorry, my question did not get the point. I mean...
I use 5x7 display and pic16f84a with 4017
but I use the program for 16f84 and only f84
then the program does not work actually...
in the program, 'TE moving sign' will be displayed moving...
but in reality, one output of column is found to fail ,not in other program
I think something goes wrong....
Pls explain me....
with thanks,

Program written for 16f84.....will not work on a 16f84a. So try recompiling your codes for 16f84a.....

Good luck

you also need to edit your source code. I don't know which software you are using, but try to include the header file of 16f84a at the very first position of your source code.

I don't like to quibble but there are no software differences between the 16F84 and 16F84A. The 84A can run at 20 mhz while the 84 can only run at 10 mhz. If you use the same clock frequency as the non-A design, the hex file should run just fine.

Now, you need to tell your programmer that you are programming a 16F84A - I believe the programming algorithm is different. Most programmers will allow you to do this (use an F84 hex with an F84A chip).

There are also some differences in the port input high voltage minimums though they shouldn't cause a problem working with CMOS.

There is a microchip migration document (84 to 84A) you can look for more detail.

I'm sure your hardware is in error. Like I said earlier, without more information, it is hard to help you.

Do all the other columns work? If one fails to light up, I'd look for a bad connection.


ps, good luck, I'm gone for a week...

I also say that there is no basic and important difference between 84 and 84a.
I think your programm has a very little problem.check again your program.
good luck.

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