> -----Oorspronkelijk bericht-----
> Van: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] 
> Namens mattschinkel
> Verzonden: maandag 18 januari 2010 21:18
> Aan: piclist@mit.edu
> Onderwerp: Re: [PIC] ICSP, bootloader, reset button schematic
> 
> 

What programmer are you using?
> The ICSP connector is one on my programmer, I varified it 
> with some microchip documents, and it is standard. 
> 
I only was regeing to the ICSP part not the RS232 becourse that part
looked very odd  to me.
> That PDF that was posted does not appear to have a serial 
> port for a bootloader, the schematic is cut off. It also has 
> some components that are not available to me.
> 

If you look at Microchip documentation on programming you wil see
where the resisters are placed. It may work in this schematic but wil
it in the complete application?
> I can remove the resistors from the data lines. Someone 
> suggested them because PGD/PGC go high in my full schematic. 
> It works with these resistors, and should not hurt to have them.
> 

With a diode in that line the actual voltage wil be 11.4 volt NOT 12V
on VPP1
> VPP1 is 12v, the PIC requires 12v in order to program. It is 
> only 12v during ICSP programming.
> 

Dont put the cap than there at all. A capacitor wil alway a DC
current. This is basic electronics!
> This 12v will not go back into my serial port because of cap 
> C1. I suppose it is acting like a filter. I'm not sure, but 
> there may be a short voltage spike that will get past C1 
> however, and I don't know how to get rid of it, or if I 
> should worry about a short voltage spike like this. Consider 
> the serial port to be a 5V IC. What can I do here?
> 

A user should never do some ICSP and if he presses the reset button
then your manual is not correct.
> The other issue can think of, is that if the user starts ICSP 
> programming, and presses the reset button at the same time, 
> there will be a high current (up to 120mA) from VPP1 to R5, 
> then to GND.
Thats why the diode in my schematic is placed where it is.
> 
> Any suggestions would be nice. I would like a good solution 
> for myself and for others.
These are all good suggetions i think refering to my own experions.
> 
> Matt.

Harry
> 
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> atic-tp27200156p27216099.html
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