EEPROM Issue

[HenrikOlsson]

Now there's a problem description if I've ever seen one :-)

My bet is that it has something to do with the interrupts. Have you tried to disable the USB comms and change/save/read back the EEPROM values in some other way just to verify that the routine that does the EEPROM writing is actually working properly. Not that I see why it shouldn't but it'll give you further clues and/or verification that it IS the USB comms/interrupts that's the culprit.

I'm surprised that your approach with the rotation variable didn't work. I was going to suggest to put the "write to EEPROM routine (one byte at the time)" in the USB Service routine but if your main routine doesn't run slower than the USB service interval your approach would basically do the same thing. The manual says that the WRITE command is self timed and "may" take up to 10ms, have you measured how long it actually takes?

How long does your main code take to exectute? Can you, as a test, disable interrupts al togheter and just call the USB service routine once each pass?

/Henrik.

[richard]

one more thought, do any of your isr routines alter the eecon registers , ie a read eprom

[mpgmike]

Thanks for the thoughts. I tried something, in the subroutine to SaveChanges I used WRITE 132,150 instead of WRITE 132,CB. The retrieved value was 150. It's not an EEPROM issue after all. Somehow my variables are getting corrupted somewhere. I'm reviewing all code with a "magnifying glass in one hand and a fine tooth comb in the other" to try to find where things are going awry. Thanks all.

[Ioannis]

write 132,CB is not correct. You have to write 132,$CB.

Ioannis

[mpgmike]

No, CB is the name of my variable, not the value.

[HenrikOlsson]

Do you have (or can you add) a debug port (EUSART, SEROUT, DEBUG)?
If so, then print the value of your variable out before calling the write routine, before executing the write command, after executing the write command, read the value back immediately after and print it out again.

Is CB declared as a BYTE?

If you're indexing arrays somewhere then doublecheck that you're not writing outside the range of the array.

[mpgmike]

CB is declared as a BYTE. I checked the arrays' indexing several times. I have a spread sheet with all the variables listed, size (BIT, BYTE, etc), USB ID#, the internal code used to communicate each variable with other PICs on the board (there are a total of 6), and some other criteria. I've been working on this project for the past several years. It's due in less than 2 weeks.

I decided to rebuild the HIDmaker side of things. I found several variables, including arrays, that were structured as signed bytes. I'm dealing with the sign in software and forgot I did that earlier. I will be totally revamping it around the proper non-signed bytes and try again.