Posted by Vasile Surducan February 16, 2005

--- In , Dwayne Reid <dwayner@p...> wrote:
> At 04:03 AM 2/15/2005, Vasile Surducan wrote:
> > >
> > > I offer caution as the negative rail of the PC Com Port,
nominally
> > > -8 VDC,
> > > is used as ground on the programmer and this is fine so long
as the
> > > programmer is isolated from other circuitry. However, in using
the
> > > ICSP connector to wire to a PIC in a circuit that is
referenced to
> > > ground will cause the PC Com port's negative rail to be
connected to
> > ground.
> > > The programmer will not work.
> >
> > Such remark comming from a teacher makes me at least to smile.
The
> >programmer in discution is not a debugger nor a developing board
> >which is permanently connected to a computer port.
> >The user application ground have nothing to do with the computer
> >ground. It might be connected to any potential comming from the
RS232
> >lines from the computer.
>
> Actually, I suspect he speaks from direct experience. If a person
is using
> ICSP while developing a project, that person probably has test
equipment
> connected to the circuit. A grounded scope probe is all that it
takes to
> make the programmer fail to work.
>
> I don't know about you, but I generally have a large number of
devices
> connected to my prototype circuits. There is usually always a
scope hooked
> up (may be just the ground lead most of the time - I tend to use a
scope
> instead of a multi-meter), many of my circuits use a serial port
(also
> grounded via the PC it is connected to), etc. Trying to use a JDM
> programmer in-circuit on those projects will not work.
>
> Finally, keep in mind that his normal audience are college
students. They
> don't have the benefit of years of experience and might have a
very hard
> time figuring out why the chip isn't programming. Quite frankly,
students
> simply don't need that kind of aggravation.

Dwayne, like usually you have (partially) right.
However just try to remind you that you're already on the mined
field when trying to program a PIC soldered on a board with your
scope probe ground connected to the board's ground. Immagine just
that your scope is plugged on other mains phase than your computer.

It's a simple thing which any student (remember: a future engineer)
must know it. Like it must know that this was one reasons why
Tektronics has developed the multi channel scope with isolated
grounds.
A student which is programming with JDM or other programmer chosen
from the thousands, and doesn't know why is programming when is
programming and when not, is not much happy than one who knows those
things. A student which has no time to discover the problem becomes
usually our boss. And then he will never have enough time.

BTW, I have some projects where the PIC is floated on the mains, but
I never tried an ICSP with 316 Vpp on it... After the mains is
powered off and disconnected, programming works well. Just an
example.

So the conclusion is simple. Use the right programmer at the right
place, student or old fox engineer.
:) best regards,
Vasile


Posted by Dwayne Reid February 15, 2005
At 04:03 AM 2/15/2005, Vasile Surducan wrote:
> >
> > I offer caution as the negative rail of the PC Com Port, nominally
> > -8 VDC,
> > is used as ground on the programmer and this is fine so long as the
> > programmer is isolated from other circuitry. However, in using the
> > ICSP connector to wire to a PIC in a circuit that is referenced to
> > ground will cause the PC Com port's negative rail to be connected to
> ground.
> > The programmer will not work.
>
> Such remark comming from a teacher makes me at least to smile. The
>programmer in discution is not a debugger nor a developing board
>which is permanently connected to a computer port.
>The user application ground have nothing to do with the computer
>ground. It might be connected to any potential comming from the RS232
>lines from the computer.

Actually, I suspect he speaks from direct experience. If a person is using
ICSP while developing a project, that person probably has test equipment
connected to the circuit. A grounded scope probe is all that it takes to
make the programmer fail to work.

I don't know about you, but I generally have a large number of devices
connected to my prototype circuits. There is usually always a scope hooked
up (may be just the ground lead most of the time - I tend to use a scope
instead of a multi-meter), many of my circuits use a serial port (also
grounded via the PC it is connected to), etc. Trying to use a JDM
programmer in-circuit on those projects will not work.

Finally, keep in mind that his normal audience are college students. They
don't have the benefit of years of experience and might have a very hard
time figuring out why the chip isn't programming. Quite frankly, students
simply don't need that kind of aggravation.

dwayne --
Dwayne Reid <>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax

Celebrating 20 years of Engineering Innovation (1984 - 2004)
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commercial email nor is intended to solicit commercial email.


Posted by Leon Heller February 15, 2005
----- Original Message -----
From: "Vasile Surducan" <>
To: <>
Sent: Tuesday, February 15, 2005 11:03 AM
Subject: [piclist] Re: 16F628 in-circuit programming problem >
>
> --- In , "jgalinat2004" <jgalinat@o...> wrote:
>> Hi,
>> Re: the Olimex PG2C I found this info from Peter H. Anderson who
>> teaches
>> Embedded contollers at Morgan State University,in Baltimore
> Marland.
>> It is
>> info from one of his PG2C auctions:
>> "The latest units I received from Olimex (PG2C) have an added six
>> terminal
>> connector for In Circuit Serial Programming (ICSP). I caution
> against
>> using
>> this to connect to external circuitry. Rather, use the on-board
>> sockets for
>> programming.
>>
>> I offer caution as the negative rail of the PC Com Port, nominally -
> 8
>> VDC,
>> is used as ground on the programmer and this is fine so long as the
>> programmer is isolated from other circuitry. However, in using the
>> ICSP
>> connector to wire to a PIC in a circuit that is referenced to
> ground
>> will
>> cause the PC Com port's negative rail to be connected to ground.
> The
>> programmer will not work. > Such remark comming from a teacher makes me at least to smile. The
> programmer in discution is not a debugger nor a developing board
> which is permanently connected to a computer port.
> The user application ground have nothing to do with the computer
> ground. It might be connected to any potential comming from the RS232
> lines from the computer. This is the principle of the JDM programmer.
> Any potential of the COM port (positive or negative) may be connected
> with the users PCB application ground as long as the ground line of
> the COM port is not connected also with the user PCB ground (which
> means short circuit). And of course in JDM or PG2C programmer this
> short circuit is not connected, only if the user is trying to
> communicate with the PC while is programming the PIC (crazy thing,
> attention please the thing is crazy, not other person!) > Leon, the JDM ICSP problem is produced by the very small programming
> current (and sensitive voltage level of VPP) achieved from the port.
> If all other consumers on the application board are not carefully
> isolated from the ICSP lines, the programming verification sequence
> will return error. That's why some PIC's may be programmed and others
> may not.


I was beginning to think it must be something like that.

Leon --


Posted by Vasile Surducan February 15, 2005

--- In , "jgalinat2004" <jgalinat@o...> wrote:
> Hi,
> Re: the Olimex PG2C I found this info from Peter H. Anderson who
> teaches
> Embedded contollers at Morgan State University,in Baltimore
Marland.
> It is
> info from one of his PG2C auctions:
> "The latest units I received from Olimex (PG2C) have an added six
> terminal
> connector for In Circuit Serial Programming (ICSP). I caution
against
> using
> this to connect to external circuitry. Rather, use the on-board
> sockets for
> programming.
>
> I offer caution as the negative rail of the PC Com Port, nominally -
8
> VDC,
> is used as ground on the programmer and this is fine so long as the
> programmer is isolated from other circuitry. However, in using the
> ICSP
> connector to wire to a PIC in a circuit that is referenced to
ground
> will
> cause the PC Com port's negative rail to be connected to ground.
The
> programmer will not work.


Such remark comming from a teacher makes me at least to smile. The
programmer in discution is not a debugger nor a developing board
which is permanently connected to a computer port.
The user application ground have nothing to do with the computer
ground. It might be connected to any potential comming from the RS232
lines from the computer. This is the principle of the JDM programmer.
Any potential of the COM port (positive or negative) may be connected
with the users PCB application ground as long as the ground line of
the COM port is not connected also with the user PCB ground (which
means short circuit). And of course in JDM or PG2C programmer this
short circuit is not connected, only if the user is trying to
communicate with the PC while is programming the PIC (crazy thing,
attention please the thing is crazy, not other person!) Leon, the JDM ICSP problem is produced by the very small programming
current (and sensitive voltage level of VPP) achieved from the port.
If all other consumers on the application board are not carefully
isolated from the ICSP lines, the programming verification sequence
will return error. That's why some PIC's may be programmed and others
may not.

I do not have nothing in common with Olimex products, I do not use
Olimex products even I see the capitalist world like cheap things.
:)

best regards,
Vasile


Posted by Leon Heller February 14, 2005
----- Original Message -----
From: "jgalinat2004" <>
To: <>
Sent: Monday, February 14, 2005 2:37 PM
Subject: [piclist] Re: 16F628 in-circuit programming problem >
>
> --- In , "leon_heller" <leon.heller@d...>
> wrote:
>>
>> --- In , "upand_at_them"
> <upand_at_them@y...>
>> wrote:
>> >
>> > I'd like to know too, because I've never been able to ICSP a
> 16F628
>> > with the PG-2C. In fact, even using the on-board socket I've
> found
>> > the PG-2C to be unreliable.
>>
>> I see the PG2C is made by Spark Fun, and is apparently the same as
>> the JDM. They use the '628 in their ICSP example, have you
> contacted
>> them about the problem?
>>
>> I've just managed to program a different '628 with ICSP, but it
> only
>> worked once! I've tried using an external supply and that doesn't
>> work either. Now, I can't get a '628 to program in the socket
> either!
>> The '88 is still OK, though.
>>
>> I think I'll try a different programmer.
>>
>> Leon
> Hi,
> Re: the Olimex PG2C I found this info from Peter H. Anderson who
> teaches
> Embedded contollers at Morgan State University,in Baltimore Marland.
> It is
> info from one of his PG2C auctions:
> "The latest units I received from Olimex (PG2C) have an added six
> terminal
> connector for In Circuit Serial Programming (ICSP). I caution against
> using
> this to connect to external circuitry. Rather, use the on-board
> sockets for
> programming.
>
> I offer caution as the negative rail of the PC Com Port, nominally -8
> VDC,
> is used as ground on the programmer and this is fine so long as the
> programmer is isolated from other circuitry. However, in using the
> ICSP
> connector to wire to a PIC in a circuit that is referenced to ground
> will
> cause the PC Com port's negative rail to be connected to ground. The
> programmer will not work.
>
> In summary, Olimex has added an ICSP connector, but I question its
> utility.
> Use the sockets on the programmer."
>
> I just figured that I would pass this along.

Thanks, Jeff.

I have my target board powered off the ICSP connector, that *should* be OK,
but I still have problems with the '628

Leon.
--


Posted by jgalinat2004 February 14, 2005

--- In , "leon_heller" <leon.heller@d...>
wrote:
>
> --- In , "upand_at_them"
<upand_at_them@y...>
> wrote:
> >
> > I'd like to know too, because I've never been able to ICSP a
16F628
> > with the PG-2C. In fact, even using the on-board socket I've
found
> > the PG-2C to be unreliable.
>
> I see the PG2C is made by Spark Fun, and is apparently the same as
> the JDM. They use the '628 in their ICSP example, have you
contacted
> them about the problem?
>
> I've just managed to program a different '628 with ICSP, but it
only
> worked once! I've tried using an external supply and that doesn't
> work either. Now, I can't get a '628 to program in the socket
either!
> The '88 is still OK, though.
>
> I think I'll try a different programmer.
>
> Leon
Hi,
Re: the Olimex PG2C I found this info from Peter H. Anderson who
teaches
Embedded contollers at Morgan State University,in Baltimore Marland.
It is
info from one of his PG2C auctions:
"The latest units I received from Olimex (PG2C) have an added six
terminal
connector for In Circuit Serial Programming (ICSP). I caution against
using
this to connect to external circuitry. Rather, use the on-board
sockets for
programming.

I offer caution as the negative rail of the PC Com Port, nominally -8
VDC,
is used as ground on the programmer and this is fine so long as the
programmer is isolated from other circuitry. However, in using the
ICSP
connector to wire to a PIC in a circuit that is referenced to ground
will
cause the PC Com port's negative rail to be connected to ground. The
programmer will not work.

In summary, Olimex has added an ICSP connector, but I question its
utility.
Use the sockets on the programmer."

I just figured that I would pass this along.

Jeff Galinat


Posted by Jeff Galinat February 14, 2005
----- Original Message -----
From: "upand_at_them" <>
To: <>
Sent: Monday, February 14, 2005 8:20 AM
Subject: [piclist] Re: 16F628 in-circuit programming problem >
>
>> I see the PG2C is made by Spark Fun, and is apparently the same as
>> the JDM. They use the '628 in their ICSP example, have you contacted
>> them about the problem?
>
> Olimex makes it. Spark Fun is just a distributor. I guess I should
> know better than to expect too much from a $10 programmer.
>
>> I think I'll try a different programmer.
>
> Me too. Do you know about the Wisp628? It does ICSP and I have
> heard a lot of good things about it.
>
> Mike >
Hi,
Re: the Olimex PG2C I found this info from Peter H. Anderson who teaches
Embedded contollers at Morgan State University,in Baltimore Marland. It is
info from one of his PG2C auctions:
"The latest units I received from Olimex (PG2C) have an added six terminal
connector for In Circuit Serial Programming (ICSP). I caution against using
this to connect to external circuitry. Rather, use the on-board sockets for
programming.

I offer caution as the negative rail of the PC Com Port, nominally -8 VDC,
is used as ground on the programmer and this is fine so long as the
programmer is isolated from other circuitry. However, in using the ICSP
connector to wire to a PIC in a circuit that is referenced to ground will
cause the PC Com port's negative rail to be connected to ground. The
programmer will not work.

In summary, Olimex has added an ICSP connector, but I question its utility.
Use the sockets on the programmer."

I just figured that I would pass this along.

Jeff Galinat


Posted by Leon Heller February 14, 2005
----- Original Message -----
From: "upand_at_them" <>
To: <>
Sent: Monday, February 14, 2005 1:20 PM
Subject: [piclist] Re: 16F628 in-circuit programming problem >
>
>> I see the PG2C is made by Spark Fun, and is apparently the same as
>> the JDM. They use the '628 in their ICSP example, have you contacted
>> them about the problem?
>
> Olimex makes it. Spark Fun is just a distributor. I guess I should
> know better than to expect too much from a $10 programmer.
>
>> I think I'll try a different programmer.
>
> Me too. Do you know about the Wisp628? It does ICSP and I have
> heard a lot of good things about it.

That's what I'll use. I ordered a programmed '628 from Wouter which I've got
somewhere. I was intending to design and make a PCB for it.

I just tried a '628 in the JDM programmer socket, and it's working again. I
really need ICSP, because I've got surface mount '627s I want to use.

Leon
--


Posted by upand_at_them February 14, 2005

> I see the PG2C is made by Spark Fun, and is apparently the same as
> the JDM. They use the '628 in their ICSP example, have you contacted
> them about the problem?

Olimex makes it. Spark Fun is just a distributor. I guess I should
know better than to expect too much from a $10 programmer.

> I think I'll try a different programmer.

Me too. Do you know about the Wisp628? It does ICSP and I have
heard a lot of good things about it.

Mike


Posted by leon_heller February 14, 2005

--- In , "upand_at_them" <upand_at_them@y...>
wrote:
>
> I'd like to know too, because I've never been able to ICSP a 16F628
> with the PG-2C. In fact, even using the on-board socket I've found
> the PG-2C to be unreliable.

I see the PG2C is made by Spark Fun, and is apparently the same as
the JDM. They use the '628 in their ICSP example, have you contacted
them about the problem?

I've just managed to program a different '628 with ICSP, but it only
worked once! I've tried using an external supply and that doesn't
work either. Now, I can't get a '628 to program in the socket either!
The '88 is still OK, though.

I think I'll try a different programmer.

Leon