[sdiy] PIC advice needed (OT)

[m.bareille at free.fr]

> I'm making a programming header and I have connections to VPP/MCLR (1), PGD
> (4), PGC (5), and GND (3).  I see some designs that also have a "PGM" pin (6)
> on the header as well, but the device does not have a PGM pin...

PGM is used with the LVP/ICSP mode = low voltage in circuit serial programming.
This allow to burn the PIC under +5V only . The Vpp pin is not used in this case
to burn the PIC and the LVP flag must be ON , else it will not work...

If you program the PIC with a 'hi voltage' you do not need the PGM pin but the
Vpp instead ( under around 13.8/14V) .  The LVP flag should be set OFF , if
present on the config bytes.

If the PGM  is absent on the IC , there are chances that the PIC cannot be
burned with LVP/ICSP or use another way to do that... Check your PIC datasheet ,
chapter 'Special Features of the CPU' it should be explained here.


Thanks,

Marc B.