We are working on programmer for the PIC's and wondered which of the above
is used the most on the 16F range.
Are there any advantages to using either?
The programmer we are working on is a variation of our AVR keyfob's and
Handheld programmers, which are powered by a battery mainly, the handheld
programmers can be powered by an external supply.
I wasn't sure if this was the correct topic tag to use so if it was wrong
then please feel free to change it but please also mail this tag as I will
be watching the [PIC] topic.
> Hi,
>
> We are working on programmer for the PIC's and wondered which
> of the above [LVP or HVP] is used the most on the 16F range.
I'd say HVP.
>From the top of my head, I can remember any of the
"hobbyist" programmers that even support LVP...
>From what I understand, LVP isn't that popular. Either one
used HVP (where you can do *anything*) or uses some
bootloader. LVP commes somewhere in between. Falls
"between the chairs", as we say here in Sweden.
On Thu, Jan 06, 2005 at 03:52:33PM -0000, BryanW wrote:
> Hi,
>
> We are working on programmer for the PIC's and wondered which of the above
> is used the most on the 16F range.
HVP.
>
> Are there any advantages to using either?
The only advantage of LVP is that you don't have to have a high voltage
present to program the part. LVP is inconvenient because it permanently
removes a usable I/O pin from use. And that I/O pin is in the middle of
an 8 bit port.
Make the programmer HVP if you can. For all of the flash parts, the Vpp
voltage requires almost no current. So even if it's battery powered the
battery should last a long long time.
> Hi,
>
> We are working on programmer for the PIC's and wondered which of the
> above is used the most on the 16F range.
>
> Are there any advantages to using either?
>
> The programmer we are working on is a variation of our AVR keyfob's
> and Handheld programmers, which are powered by a battery mainly, the
> handheld programmers can be powered by an external supply.
>
> I wasn't sure if this was the correct topic tag to use so if it was
> wrong then please feel free to change it but please also mail this tag
> as I will be watching the [PIC] topic.
>
> Cheers,
>
> BryanW
> --
> Software Engineer - Embedded Results Ltd,
> http://www.kanda.com
> https://www.kanda.com/stk200.html
I use HVP with ICSP because I hate to lose a pin just to avoid one
development 13v power supply. Plus it's not difficult to create the 13v
from a smaller supply for little money, and a programmer which does HVP
can also easily handle LVP if it makes more sense in a project.
> Hi,
>
> We are working on programmer for the PIC's and wondered which of the
> above is used the most on the 16F range.
>
> Are there any advantages to using either?
>
> The programmer we are working on is a variation of our AVR keyfob's
> and Handheld programmers, which are powered by a battery mainly, the
> handheld programmers can be powered by an external supply.
>
> I wasn't sure if this was the correct topic tag to use so if it was
> wrong then please feel free to change it but please also mail this tag
> as I will be watching the [PIC] topic.
>
> Cheers,
>
> BryanW
> --
> Software Engineer - Embedded Results Ltd,
> http://www.kanda.com
> https://www.kanda.com/stk200.html
BryanW wrote:
> We are working on programmer for the PIC's and wondered which of the
> above is used the most on the 16F range.
>
> Are there any advantages to using either?
Yes. High voltage programming allows for all programming features, such as
complete bulk erase even when code protection was set. LVP also requires a
pin to be dedicated for that purpose.
I use LVP only when absolutely required. This has so far happened only
once. In that case the PIC was peripheral to a bigger processor, and the
customer wanted to be able to update the PIC firmware in the field via the
big processor.
*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
> We are working on programmer for the PIC's and wondered which
> of the above
> is used the most on the 16F range.
above? you probably mean the subject line? HVP, of course. But I see you
are planning yet another programmer, and I already sell one, so forget
my first answer, by all means create an LVP-only programmer!
Wouter van Ooijen
-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu
>> We are working on programmer for the PIC's and wondered which
>> of the above
>> is used the most on the 16F range.
>
> above? you probably mean the subject line? HVP, of course. But I see you
> are planning yet another programmer, and I already sell one, so forget
> my first answer, by all means create an LVP-only programmer!
>
> Wouter van Ooijen
Ah! Competition :)
Not really though, our programmer is a portable keyfob, they are stand
alone, one button press things. We intended to do a version a while back but
saw a product called a fobbit and thought that it was already available. I
haven't seen this mentioned for quite a while, so I thought it was a way to
go now. The keyfob has 32k of storage space.
The other programmer we will create is a larger version that takes a 9v
battery and can be powered via a power supply if required, with a lot more
memory. 128k in fact. We have been selling these products for the AVR for
quite a number of years now, we have been slowly increasing the range of
supported devices.
The engineer that originally was looking at the datasheets though has seen
that the LVP is not available on all 16F parts and that the problem we
thought we had, mainly to do with current consumption is not a problem on
the 16F part we think, but may be a 16C thing. He saw that the 16C had a
high drain on the Vpp pin and assumed the 16F had the same, but says the 16F
datasheets he's looked at so far leave this unspecified.
I was asked to see if the LVP stuff was the way to go, but maybe not eh! :)
> He saw that the 16C had a high drain on the Vpp pin...
Yes, since Vpp is actualy used to "burn" the (one-time-
programming) PROM in the C-parts.
> and assumed the 16F had the same...
No, since the Vpp is only used as an "signal" to the F-parts
to switch to "programming mode". The needed programming
voltages are then generated internaly. The same internal
voltage generator is used when you "program" the Flash
memory from the application code, in which case there is (external)
no Vpp applied at all, of course. And the C-parts can't be programmed
from the app code, of course...
> but says the 16F
> datasheets he's looked at so far leave this unspecified.
Wouter van Ooijen wrote:
> But I see
> you are planning yet another programmer, and I already sell one, so
> forget my first answer, by all means create an LVP-only programmer!
Yeah, forget what I said earlier and change my answer to Wouter's ;-)
*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
>The engineer that originally was looking at the datasheets though has seen
>that the LVP is not available on all 16F parts and that the problem we
>thought we had, mainly to do with current consumption is not a problem on
>the 16F part we think, but may be a 16C thing. He saw that the 16C had a
>high drain on the Vpp pin and assumed the 16F had the same, but says the
>16F datasheets he's looked at so far leave this unspecified.
>
>I was asked to see if the LVP stuff was the way to go, but maybe not eh! :)
If you are going to build a programmer, don't use LVP and please *DO*
support the 12C & 16C parts. We still use far more "C" parts than we do
"F" parts (thousands per year more) and many of the new programmers now
being made available can't supply the Vpp current that the "C" family requires.
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> If you are going to build a programmer, don't use LVP and please *DO*
> support the 12C & 16C parts. We still use far more "C" parts
> than we do
> "F" parts (thousands per year more) and many of the new
> programmers now
> being made available can't supply the Vpp current that the
> "C" family requires.
But if you are into such numbers, are you seriously interested in yet
another prgrammer? I would think you would stick to some trusted,
expensive Microchip progger and be happy with it?
Wouter van Ooijen
-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu
engineer.cotse.net, and 
