Tal Dayan wrote:
> Built today the El Cheapo programmer according to the latest software (yes,
> the 2N7000 marking was wrong and I damaged one). It passed all the debug
> mode tests but refuses the program (location 0x00 always return 0xfff or
> something like that).
>
> My question are:
>
> 1. I am trying to program 16LF84A. The software has only 16F84A. Is it ok ?
>
> 2. I am using a notebook computer (Sony Vaio f450). Is this a problem ?
>
> 3. I am using a long cable (10'). Is it a problem ?
>
> 4. The 12V regulator is 7812 instead of 78L12 so I had to increase the power
> to about 19V to get the right VPP.
>
> 5. Is the El Cheapo any good and if not, what is a good and cheap
> alternative ?
>
>
> BTW, when the El Cheapo report a verify error, it keeps the programming
> voltage on. Looks like
> a bug to me.
>
> Any help will be greatly appreciated.


The error you're seeing (location 0 returning 0xFFF) is caused by a
change in recent versions of MPLAB. The default output format is now
32-bit hex format (INHX32) instead of 8-bit hex (INHX8M); the El Cheapo
software only understands the latter.

To fix the problem, you need to change your project settings in MPLAB.
Go to the Project menu, and choose Edit Project. Down near the bottom of
that window, there is a list of project files; the first one should be
for the .hex file. Click on that, and then click on the Node Properties
button. Click on INHX8M in the windows that appears, and then say OK to
everything. Rebuild your project, and you should be ready to go.

By the way, changing the regulator to a 7812 isn't really a good idea;
as Myke explains on the El Cheapo web site, the current limit in the
design was intentional, and allows for safe "hot-plugging" of the PIC.
You might want to get your hands on a 78L12 somewhere.

Using a 16LF84A instead of a 16F84A isn't a problem. The "LF" means that
your part is rated for low-voltage operation. Remember, though, that the
El Cheapo is a "development" rather than "production" programmer - the
latter is required to test parts over their full voltage range. If you
actually want to design circuits that operate your 16LF84A at 2 volts,
you may want to get your hands on a production-grade programmer.

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