First build, need assistance trouble shooting SOLVED!!!!!!!!!

[urthegman]

What exactly is a check sum anyway?

[chrisatpsu]

A checksum or hash sum is a fixed-size datum computed from an arbitrary block of digital data for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one. If the checksums match, the data were almost certainly not altered (either intentionally or unintentionally).

a math problem that looks at parts of a file, that you can check again to make sure it's the same answer...  same answer means same complete file.

[Jeffl]

The checksum for the firmware is listed at the link below for the Express.  If you read the firmware loaded on the PIC with the PicKIT software you should get the values listed.  This will tell you the firmware that was loaded is correct and not corrupt.

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More info on Checksum

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If you have a new Lynx Express, try reading the firmware from the PIC after it's initially built, it's a fun little exercise.


You can find instructions on how to program/read the PIC using the PicKIT in the Express Manual.

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Good Luck.

[urthegman]

Thanks guys, you learn something new every day around here!

[chrisatpsu]

doesn't the checkcum get altrered when you change the start address?

[tbone321]

Any change to the file should affect the checksum and changing the start addess changes the file.

[Jeffl]

You would not think this would be the case, but yes it does change the checksum as you change the address.  I didn't believe it, so I had to test it. 

[tbone321]

that's the whole purpose of the checksum.  It is designed to detect changes in the file even if the file is the same size.

[Titus]

I went through the same thing on mine today.  A re-flash cured all.

[cpnbnanamn]

I'm glad I found this..  Just built one of the LE's from this last co-op, and am getting the same thing..  No output from the display, LED's are in properly, and #6 lights dimly.  Time to dig out the Pickit3!

[cpnbnanamn]

THAT GOT IT!!  That controller appears to be good now!!  Thanks for the info, guys!

-Roger