Blank Variable

[GatorGuy]

I need to read the first bit of the EEPROM and store that value into a variable. That part is easy, however, I need the program to do something if the EEPROM is empty such as the first time the pic is turned on. I cant set it each time the pic is turned on because I want it to store what was last used.

eg.

s1 var byte

READ 0, s1
if s1 = "" then s1 = "1" <---- This is where I get errors
.
.
.
'rest of the program

How can I change this?

[mackrackit]

If the EEPROM has not been changed it will read HEX FF, BIN 11111111 or DEC 255.

[Acetronics2]

Hi, Dave

Gator must be told the numbers to compare to do no use " " ( quotes ) and the "BLANK" value does not exist.

Suppose it' as a re-used chip ... everything ( 0 -255 ! ) possible as a value.

Also Note I have received brand new chips which EEPROM had been tested ( value of the location written for the 0, 8, 16, 24, .... th locations , and Zeroes everywhere )...

Alain

[mackrackit]

Good points.

So maybe the solution for Gator is to write a program to run that will write a known value to the EEPROM then re-program the PIC with the working code.

Might not be so good for production though.

[Acetronics2]

Gator just wants the values not to be overwritten @ further power ups ...

so, it only needs to write a SURE default value @ first programming ( DATA ...)

I do agree the DATA line must be commented or modified ,if some minor ( ? ) prog mods are done AND he doesn't want to loose previous values.

But this never happens in real life ... does it ???

Alain

[mackrackit]

Idea...
Not sure exactly how to do it...

Use WRITECODE to over write the DATA line.

Where is the DATA line???