Code not running on PIC16F88 when pic kit 3 is disconnected

Started by Andrew September 9, 2010
Looking back through your posts and replies, I didn't see any mention of bypass caps on the chip's power pins.

Do you have a 0.1 uf cap across the chip's power pins near the pins? This is an often overlooked requirement.

Also, have you verified that the power supply is ok? With the PICkit connected, is it powering the circuit? And again, does the voltage regulator have input and output caps as shown in the data sheet?
Some common problems for PIC circuits are identified here:

http://digital-diy.com/component/content/article/178-commandments-for-using-pics.html

Jon

You don't have a pull up on MCLR-

Virgil Stamps

From: p... [mailto:p...] On Behalf Of
Andrew
Sent: Monday, September 20, 2010 6:00 AM
To: p...
Subject: [piclist] Re: Code not running on PIC16F88 when pic kit 3 is
disconnected

Hi Jon,

Thanks for your suggestions.

I have posted my schematic at:

http://f1.grp.yahoofs.com/v1/oDCXTLojxFogamOWv3Agx20diqAYijFXSEWH1tpwAli0Pw-
0upxs7F_ZilMzWuTnLYEYc_loJ8XSmnNhwHL7P7izdh5ssA/Schematic.bmp

for examination.

I have measured the voltage to the processor and it is correct. I have
fitted a 0.1uF cap as close as possible to the processor, and I have
appropriate capacitors fitted each side of the voltage regulator.

Does anyone have any further ideas please?

Thanks

Andrew

--- In p... , "Jon"
wrote:
>
> Looking back through your posts and replies, I didn't see any mention of
bypass caps on the chip's power pins.
>
> Do you have a 0.1 uf cap across the chip's power pins near the pins? This
is an often overlooked requirement.
>
> Also, have you verified that the power supply is ok? With the PICkit
connected, is it powering the circuit? And again, does the voltage regulator
have input and output caps as shown in the data sheet?
> Some common problems for PIC circuits are identified here:
http://digital-diy.com/component/content/article/178-commandments-for-using-
pics.html
>
> Jon
>
Hi Virgil,

Thanks for you reply.

R6 is the pull up for MCLR, and I have confirmed that MCLR is being pulled up.

Thanks

Andrew

--- In p..., "Virgil Stamps" wrote:
>
> You don't have a pull up on MCLR-
>
> Virgil Stamps
>
>
>
>
>
> From: p... [mailto:p...] On Behalf Of
> Andrew
> Sent: Monday, September 20, 2010 6:00 AM
> To: p...
> Subject: [piclist] Re: Code not running on PIC16F88 when pic kit 3 is
> disconnected
>
>
>
>
>
> Hi Jon,
>
> Thanks for your suggestions.
>
> I have posted my schematic at:
>
> http://f1.grp.yahoofs.com/v1/oDCXTLojxFogamOWv3Agx20diqAYijFXSEWH1tpwAli0Pw-
> 0upxs7F_ZilMzWuTnLYEYc_loJ8XSmnNhwHL7P7izdh5ssA/Schematic.bmp
>
> for examination.
>
> I have measured the voltage to the processor and it is correct. I have
> fitted a 0.1uF cap as close as possible to the processor, and I have
> appropriate capacitors fitted each side of the voltage regulator.
>
> Does anyone have any further ideas please?
>
> Thanks
>
> Andrew
>
> --- In p... , "Jon"
> wrote:
> >
> > Looking back through your posts and replies, I didn't see any mention of
> bypass caps on the chip's power pins.
> >
> > Do you have a 0.1 uf cap across the chip's power pins near the pins? This
> is an often overlooked requirement.
> >
> > Also, have you verified that the power supply is ok? With the PICkit
> connected, is it powering the circuit? And again, does the voltage regulator
> have input and output caps as shown in the data sheet?
> >
> >
> > Some common problems for PIC circuits are identified here:
> >
> >
> http://digital-diy.com/component/content/article/178-commandments-for-using-
> pics.html
> >
> >
> >
> > Jon
>

Hi Jon,

Thanks for your suggestions.

I have posted my schematic at:

http://f1.grp.yahoofs.com/v1/oDCXTLojxFogamOWv3Agx20diqAYijFXSEWH1tpwAli0Pw-0upxs7F_ZilMzWuTnLYEYc_loJ8XSmnNhwHL7P7izdh5ssA/Schematic.bmp

for examination.

I have measured the voltage to the processor and it is correct. I have fitted a 0.1uF cap as close as possible to the processor, and I have appropriate capacitors fitted each side of the voltage regulator.

Does anyone have any further ideas please?

Thanks

Andrew

--- In p..., "Jon" wrote:
>
> Looking back through your posts and replies, I didn't see any mention of bypass caps on the chip's power pins.
>
> Do you have a 0.1 uf cap across the chip's power pins near the pins? This is an often overlooked requirement.
>
> Also, have you verified that the power supply is ok? With the PICkit connected, is it powering the circuit? And again, does the voltage regulator have input and output caps as shown in the data sheet?
> Some common problems for PIC circuits are identified here:
>
> http://digital-diy.com/component/content/article/178-commandments-for-using-pics.html
>
> Jon
>

Hi,

I have held fire for a couple of days to be absolutely sure, but I seem to have resolved the problem. It was something to do with an inductor I had fitted to the psu.

One again I would like to thank you all for your time and suggestions.

Andrew

--- In p..., "Andrew" wrote:
>
> Hi Virgil,
>
> Thanks for you reply.
>
> R6 is the pull up for MCLR, and I have confirmed that MCLR is being pulled up.
>
> Thanks
>
> Andrew
>
> --- In p..., "Virgil Stamps" wrote:
> >
> > You don't have a pull up on MCLR-
> >
> > Virgil Stamps
> >
> >
> >
> >
> >
> > From: p... [mailto:p...] On Behalf Of
> > Andrew
> > Sent: Monday, September 20, 2010 6:00 AM
> > To: p...
> > Subject: [piclist] Re: Code not running on PIC16F88 when pic kit 3 is
> > disconnected
> >
> >
> >
> >
> >
> > Hi Jon,
> >
> > Thanks for your suggestions.
> >
> > I have posted my schematic at:
> >
> > http://f1.grp.yahoofs.com/v1/oDCXTLojxFogamOWv3Agx20diqAYijFXSEWH1tpwAli0Pw-
> > 0upxs7F_ZilMzWuTnLYEYc_loJ8XSmnNhwHL7P7izdh5ssA/Schematic.bmp
> >
> > for examination.
> >
> > I have measured the voltage to the processor and it is correct. I have
> > fitted a 0.1uF cap as close as possible to the processor, and I have
> > appropriate capacitors fitted each side of the voltage regulator.
> >
> > Does anyone have any further ideas please?
> >
> > Thanks
> >
> > Andrew
> >
> > --- In p... , "Jon"
> > wrote:
> > >
> > > Looking back through your posts and replies, I didn't see any mention of
> > bypass caps on the chip's power pins.
> > >
> > > Do you have a 0.1 uf cap across the chip's power pins near the pins? This
> > is an often overlooked requirement.
> > >
> > > Also, have you verified that the power supply is ok? With the PICkit
> > connected, is it powering the circuit? And again, does the voltage regulator
> > have input and output caps as shown in the data sheet?
> > >
> > >
> > > Some common problems for PIC circuits are identified here:
> > >
> > >
> > http://digital-diy.com/component/content/article/178-commandments-for-using-
> > pics.html
> > >
> > >
> > >
> > > Jon
> > >
>