Wouter van Ooijen writes:

> > > A lot of hobbyist projects are wire wrapped, assembled 
> > point to point,
> > > on stripboard, or homemade PCBs.  In all of those cases, 
> > allowing for
> > > ICSP can add more complexity than it removes.
> > > 
> > > I'm not sure why dip-clips...
> > 
> > But doesn't (in curcuit use of) dip-clips add the same
> > complexity (if any) as any other variant of ICSP ??
> > It's it just another, slightly different hardware solution, not ?
> 
> two different points:
> 1) your circuit must allow for ICSP (MCLR, RB6, RB7, etc)
> 2) the physical realisation must allow for connection of the programmer
> 
> A DIP clip makes 2) trivial (provided that you use a DIP chip). I think
> the above OP talked about 2). Of course the 1) aspect remains.

Here is what I plan to do once my circuits go from breadboard to PCB:

Solder in a single row of 8 header pins (or two rows of 4 pins)
something like this:


PIC         header pins
|           |
|           |   jumpers      ICSP
|           |   |            |
v           v   v            v

-----+
     |
VDD  |------*         O----- VDD
     |
MCLR |------* O-+     O----- MCLR
     |          |
     |   <--* O-+     O
     |
PGC  |------* O-+     O----- PGC
     |          |
     |   <--* O-+     O
     |
PGD  |------* O-+     O----- PGD
     |          |
     |   <--* O-+     O
     |
VSS  |------*         O----- VSS
     |
-----+

The basic deal is that the programming is *physically* isolated from
the rest of the circuit.  In operation, jumpers are used on the pins
to send MCLR/PGC/PGD to route to operational functionality.  For
programming, these jumpers are removed and the ICSP is plugged into
the DIP/SIP header.  Jumpers could also be used to isolate VDD/VSS,
but I'm not sure this will be necessary is most cases.

As a *hobbyist*, though, I'd probably try to select a uC with enough
extra pins so that I wouldn't need the jumpers at all, and could just
leave the programmer in-place for both programming and debugging.

Note that this is just a *plan* and not something I have actually
implemented, so comments are of course very much welcomed!

-p.

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