PIC prgramming

P

Periproct

Guest
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect that
the PIC is in low voltage programming mode, hence RA4 is not being used as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration word
is 0. The book of words says that if I can auto identify the PIC with PPP it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).

I appreciate it is a long shot someone on here knowing my board and software
but is there something I'm missing regarding programming this PIC in HVP
mode so I can get my port RA4 back?

Regards, Nigel
 
"Periproct" <Periproct@btinternet.com> wrote in message
news:OJCdnRHx4K2fRXLWnZ2dnUVZ8r-dnZ2d@bt.com...
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect
that the PIC is in low voltage programming mode, hence RA4 is not being
used as an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration
word is 0. The book of words says that if I can auto identify the PIC with
PPP it is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).

I appreciate it is a long shot someone on here knowing my board and
software but is there something I'm missing regarding programming this PIC
in HVP mode so I can get my port RA4 back?

Regards, Nigel
Just to add to my post.
Click to expand...
Time is getting short as this is a school project that has to be in this
coming week. I can get a basic programmer (from Maplin in the UK) which
doesn't have the option for LVP. I'm wondering if, in desperation, this
might solve my problem.
 
"Merciadri Luca" <merciadriluca@gmail.com> wrote in message
news:ad118bb1-1121-41a3-b83f-8d2810df62a0@q23g2000vba.googlegroups.com...
On May 16, 1:32 pm, "Periproct" <Peripr...@btinternet.com> wrote:
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect
that
the PIC is in low voltage programming mode, hence RA4 is not being used
as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration
word
is 0. The book of words says that if I can auto identify the PIC with PPP
it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).
According to http://www.voti.nl/swp/, applying a high voltage (around
14V) on the MCLR pin (input only) makes HVP. It seems that it is under
LVP, but then?

Thanks for the reply. I'll try and put a meter on MCLR and see if it goes
Click to expand...
high when it programs. Or is it the case I can use a bit of jumper wire to
apply 14V to that pin and force it to HVP.
Regards
 
"Merciadri Luca" <merciadriluca@gmail.com> wrote in message
news:ad118bb1-1121-41a3-b83f-8d2810df62a0@q23g2000vba.googlegroups.com...
On May 16, 1:32 pm, "Periproct" <Peripr...@btinternet.com> wrote:
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect
that
the PIC is in low voltage programming mode, hence RA4 is not being used
as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration
word
is 0. The book of words says that if I can auto identify the PIC with PPP
it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).
According to http://www.voti.nl/swp/, applying a high voltage (around
14V) on the MCLR pin (input only) makes HVP. It seems that it is under
LVP, but then?

Another question is, does it have to be 14V or will a lower voltage be OK.
Click to expand...
 
On May 16, 1:32 pm, "Periproct" <Peripr...@btinternet.com> wrote:
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect that
the PIC is in low voltage programming mode, hence RA4 is not being used as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration word
is 0. The book of words says that if I can auto identify the PIC with PPP it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).
According to http://www.voti.nl/swp/, applying a high voltage (around
Click to expand...
14V) on the MCLR pin (input only) makes HVP. It seems that it is under
LVP, but then?
 
In article <OJCdnRHx4K2fRXLWnZ2dnUVZ8r-dnZ2d@bt.com>,
Periproct@btinternet.com says...
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect that
the PIC is in low voltage programming mode, hence RA4 is not being used as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration word
is 0. The book of words says that if I can auto identify the PIC with PPP it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).

I appreciate it is a long shot someone on here knowing my board and software
but is there something I'm missing regarding programming this PIC in HVP
mode so I can get my port RA4 back?
Click to expand...
I don't know about your programming setup,
so I can't comment, but when I have an i/o
that won't respond, I usually check for a
missed peripheral control bit setting, such
as A/D, UART, comparator, etc.

Is your RA4 a full i/o, or an output-only
pin? I've been bit by that one occasionally.

IIRC, the clock output of the Pics I use is
multiplexed on RA4, and there are a few
obscure bit settings needed to get it to
function properly as a digital i/o.

Read up on all the functions sharing that
pin, esp. the register settings.

Preset all variables and periph. settings in
code; don't assume registers get set/cleared
consistently at power-up. That way lies
madness.... 8(

HTH.
 
On May 16, 3:17 pm, "Periproct" <Peripr...@btinternet.com> wrote:
"Merciadri Luca" <merciadril...@gmail.com> wrote in message

news:ad118bb1-1121-41a3-b83f-8d2810df62a0@q23g2000vba.googlegroups.com...

On May 16, 1:32 pm, "Periproct" <Peripr...@btinternet.com> wrote:
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect
that
the PIC is in low voltage programming mode, hence RA4 is not being used
as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration
word
is 0. The book of words says that if I can auto identify the PIC with PPP
it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).
According tohttp://www.voti.nl/swp/, applying a high voltage (around
14V) on the MCLR pin (input only) makes HVP. It seems that it is under
LVP, but then?

Thanks for the reply. I'll try and put a meter on MCLR and see if it goes
high when it programs. Or is it the case I can use a bit of jumper wire to
apply 14V to that pin and force it to HVP.
I am pretty sure you can.
Click to expand...
 
On May 16, 3:19 pm, "Periproct" <Peripr...@btinternet.com> wrote:
Another question is, does it have to be 14V or will a lower voltage be OK..
I think that it should be `around' 14V. I do not know their logic, but
14 V should be ok. I know, most serial ports provide [-5 ... +12] V,
and it is even lower on laptops.
Click to expand...
 
"Randy Day" <randy.day@sasktel.netx> wrote in message
news:MPG.2659d53e9cb8ca129896b8@news.sasktel.net...
In article <OJCdnRHx4K2fRXLWnZ2dnUVZ8r-dnZ2d@bt.com>,
Periproct@btinternet.com says...
I'm trying to program a PIC 16F628A using a Matrix Multimedia HP488
programmer with PPP ver 3.

The PIC should be responding to an input on RA4 but it isn't. I suspect
that
the PIC is in low voltage programming mode, hence RA4 is not being used
as
an input.
I have PPP set to disable LVP and I can see bit 7 of the configuration
word
is 0. The book of words says that if I can auto identify the PIC with PPP
it
is in LVP mode which is what I am getting.
The board has the required 14V (I've upped the PSU to get that and the on
board regulator isn't running hot and it is programming the PIC OK).

I appreciate it is a long shot someone on here knowing my board and
software
but is there something I'm missing regarding programming this PIC in HVP
mode so I can get my port RA4 back?

I don't know about your programming setup,
so I can't comment, but when I have an i/o
that won't respond, I usually check for a
missed peripheral control bit setting, such
as A/D, UART, comparator, etc.

Is your RA4 a full i/o, or an output-only
pin? I've been bit by that one occasionally.

IIRC, the clock output of the Pics I use is
multiplexed on RA4, and there are a few
obscure bit settings needed to get it to
function properly as a digital i/o.

Read up on all the functions sharing that
pin, esp. the register settings.

Preset all variables and periph. settings in
code; don't assume registers get set/cleared
consistently at power-up. That way lies
madness.... 8(

Thanks for the reply.
Click to expand...
This was a simple little circuit from Elektor so I was just squirting their
HEX into the PIC.
I've been away for a few days so have handed the programmer over to a friend
who has had the same resounding lack of success that I did. As I was doing
it for him he has sent the HEX to an Ebay PIC seller who will program the
PIC for him. He has also ordered a programmed PIC from Elektor. Hopefully
one of them will work and we can backtrack and see what we've been doing
wrong.
I'm off for another week away so the laptop will be going with me as well as
the HEX, ASM and PIC data sheet to keep me amused during the evenings.
Regards.
>
 
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