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programmed PICs for such programmers, and don’t build them except for your own use. Some
borderline cases:
•
It is allowed to design and make a Wisp648 PCB, but it is not allowed to have it made for
you by a PCB company, nor is it allowed to sell such a PCB, or to provide the PCB design
to the general public.
•
It is allowed to program a 16F648A with the Wisp648 firmware, create a PCB, or even
build a complete Wisp648 programmer for a friend, provided that it is a single programmer
(don’t start a neighborhood Wisp648 building service), and you do not make any money
doing so.
Note that there is no restriction on the use of a Wisp648 programmer. Why these restrictions at all?
Because I must make a living, and I would like my PICmicro activities to contribute to that, so I
can justify spending more time on those activities. That includes updating the Wisp648 design and
PC software for it, so in the end you will benefit too.
Can you send me the Wisp648 circuit and PCB files?
Sorry, I won't. I sell a kit containing all Wisp648 parts, including a programmed 16F648A and a
PCB. I want to encourage Do It Yourself activities, but you will have to use a breadboard, or
design your own PCB. If you want the comfort of an existing PCB: buy the kit!
Why does my Wisp648 identify itself as Wisp628?
Most PC firmware for Wisp628 checks the programmer name, and refuses to work when it is
anything but Wisp628. Wisp648 is compatible with such firmware, except that it would not work
when it revealed itself as Wisp648. So I decided to let the Wisp648 identify itself as Wisp628, at
least until all third-party PC software is modified to accept the identification ”Wisp648”.
Programming 18F fuses does not work
Some PIC fuses settings, in particular the enabling of the PLL in 18F chips, require a power-up to
take effect. Just a reset is not sufficient. By default the Wisp648 will reset the target chip after
programming, but it will not automatically cycle the power, so when you (for instance) enable the
PLL in an 18F chip for the first time you will need to remove and re-apply the power.
Your PC software sucks. I want to make my own.
No problem. But you are not the first with this idea, so you might check on the internet for third-
party PC software for the Wisp648, maybe you like it better than mine. Rob Hamerling is one
source. His website is currently at http://www.robh.nl, otherwise google will be able to find him.
But if you insist on making your own software, by all means do so. I would appreciate it if you
make your software available on the internet and drop me an email so I can mention it on the
Wisp648 page. The communication protocol used by the Wisp648 is described in other documents,
check the Wisp648 page. If these documents are not clear feel free to ask me for an explanation. Or
read the Wisp648 firmware, this too is available from the Wisp648 page.
PCB 1.05 bug
Version 1.05 of the Wisp648 PCB has a bug: the PGM line is permanently shorted to ground. The
effect is that if you use the white wire to pull the PGM/LVP pin low during programming, this pin
will permanently be pulled low, thus preventing normal use of this pin. If you don’t use this pin
you won’t notice this problem (which is why I did not discover it – thanks Johan Van Hecke!)
Now what can be done about this?
1.
When you use a target chip that does not have the LVP feature you have no problem. Read
no further (at least not for now).
