Jim,

Thanks for the wealth of information. I would appreciate any further
comments you might have. I had pretty much decided on purchasing your
WARP-13 when I came across the PIC-MCP-USB and found the USB/no power =
supply
idea intriguing, but you make some valid points.

Thanks again,
 Al

> -----Original Message-----
> From: pic microcontroller discussion list =
[mailto:PICLIST@MITVMA.MIT.EDU]
> On Behalf Of Jim Robertson
> Sent: Saturday, August 07, 2004 12:11 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [PIC:] Olimex PIC Programmers???
>=20
> >Does anyone have any experience with the Olimex PIC programmers in
> general
> >and their PIC-MCP-USB in particular?
> >
> >http://www.olimex.com/dev/pic-mcp-usb.html
> >Thanks,
> >   Al
>=20
> Note that I have retagged this thread to [PIC:]
>=20
> First, in case you don't know, I am the designer of the WARP-13 and
> business owner of NEWFOUND ELECTRONICS. As some people
> may imaging  the MCP is a competitor to the WARP-13, I thought it
> proper to disclose this.
>=20
> Not withstanding, I will call it as I see it....
>=20
> I have both a Olimex MCP and a MCP-USB that I have been playing
> with. Both these programmers do work as required and will be suitable =
for
> programming PICs.
>=20
> Personally,  I fear any device that uses a FTDI chip AND the Virtual
> Com Port (VCP) Driver.  My issues with the VCP driver include:
>=20
> 1)
> Experience of frequent crashes.
>=20
> 2)
> Virtual Comport can be reassigned and sometimes you have try several
> comport settings before finding it. (I tended to have several =
different
> FTDI devices that could be frequently plugged and unplugged. I have
> since removed them all and the VCP driver. Just to much trouble for =
me.
> Hopefully FTDI will sort out these issues.)
>=20
> 3)
> Decrease in serial throughput.  (I have seen and FTDI chip blow out =
the
> programming time of a 18F252 from 39 seconds (RS232) to 9 minutes
> and 3 seconds when used with a well known, brand name PIC programmer!)
>=20
> In relation to MPLAB, other people have commented that sometimes
> the virtual comport is assigned to comport 5 or higher. MPLAB only
> allows comports 1-4. I have personally had this problem with a FTDI
> USB-RS232 bridge (same USB interface as the MCP-USB) and the
> PICSTART Plus.
>=20
> Of Course it is possible that you may experience no difficulties or
> any problems are outweighed by the advantages the MCP-USB offers.
>=20
> Regarding these two programmers generally, as I said they most often
> work and maybe that is all you require. Free updates seem to be =
available
> from time to time (requires a second 16F876A as the updates are not
> done via a bootloader.)
>=20
> My negative points on these two programmers are:
>=20
> 1)
> Programming Vdd is hardwired for 28-pin sdip PICs and 40-pin PICs.
> That is, 5Volts is always present on the Zif  even when fitting and
> removing
> PICs! Ouch!
>=20
> 2)
> The Vdd supply to 8 & 14-pin PICs is via a diode. Clearly, this is a
> violation
> of the requirements of the programming specifications which do demand
> 4.5V for bulk erasure.  Do the Math:  5V - 0.7V =3D 4.3V. In practice =
I
> found that the drop across the diode was enough to prevent the PIC =
from
> being erased and I had to short across the diode when programming
> 8 & 14-pin PICs and then remove it for other PICs.
>=20
> 3)
> I found the programming efficiency  (theoretical time/actual program =
time)
> to be intolerably low.  Some people don't care about this sort of
> concern and maybe that is you.
>=20
> 4)
> The MPLAB - PICSTART Plus driver is crappy. It is one of the poorest
> programmer drivers I have seen. It is frustratingly slow and lacks =
utility
> features that are standard on the better 3rd party programmers.
>=20
> 5)
> These programmers only support PICs that are supported by the
> PICSTART Plus. You may find the PIC you thought would be
> supported isn't.
>=20
> In summery, they are reasonable programmers for the price but I
> cannot see one area where they standout from the crowd and
> certainly not in total.
>=20
> I did have some further comments here regarding other options
> you may want to consider. However as you have only asked for
> comment on the Olimex programmers I have held back from offering
> these comments. Let me know if you want to see these remarks.
>=20
>=20
> Regards,
>=20
> Jim
>=20

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