gnupic: Re: [gnupic] [ANN] Pikme PIC Bootloader (for 16F819 etc)
Subject:
Re: [gnupic] [ANN] Pikme PIC Bootloader (for 16F819 etc)
From:
Martin Harriss ####@####.####
Date:
26 Jul 2006 20:11:16 +0100
Message-Id: <44C7BE4F.50006@Princeton.EDU>
Frank Sergeant wrote:
...
>
> Recently, I couldn't get some 16F819 chips to program and verify
> reliably. No, I did not change my desktop PC or its serial port. I
> tried 3 or 4 PCs. I measured the Vpp (only statically, so it still
> might have been marginal). Did I get a "bad" batch of '819 chips that
> might have needed e.g. 13.5 V rather than only e.g. 11 V?
...
Don't feel too bad about this. Even Microchip has problems programming
the '819s with their hardware.
If you download MPLAB and dredge through the release notes you'll find
their work-around. I seem to recall it involves connecting a 1k
resistor between Vpp and ground, or something similar. I was having
intermittent problems programming these chips with a Picstart Plus until
I found this release note; since then I've had no problems.
BTW, this was an "old" Picstart Plus with the 17C44 in it -- the newer
ones with the 18F chip may or may not thave the same problem.
Martin
