In Circuit Serial Programming | Piclist

I would like to add ICSP to my project! I am going to setup my header as seen in this link http://www.melabs.com/support/icsp.htm. My question is that I am using my PortB 6&7 for outputs connected to an ULN2003, can I also connect to my header for programming without damaging anything? Should I add some diodes to the circuit? I am using a PIC16F628 which suggest that I connect PORTB 4 to ground to stop interference. If I have PortB 4 connected to the same ULN2003 should I jumper this to ground? Thanks in advance, ************************************** Scott Lingerfelt ************************************** --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.537 / Virus Database: 332 - Release Date: 11/6/2003

(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

It seems to me that the requirement to ground a pin (PGM) and the fact that melabs recommends the PIC be powered from a normal source rather than the programmer could cause an issue. The PIC state must be one in which the pins are floating before the ground is applied. I think you might do well to review the Microchip way of doing things - read the ICSP app notes. I have gone so far as to use a 10 pin cable header (2 columns of 5 rows). There is a shorting plug in the header for normal operation that connects Vcc and Vdd from the normal power supply to the PIC. During programming the shorting plug is removed and a programming cable inserted. This allows the programmer to control everything about the PIC as it relates to ICSP. Vcc, Vdd, Pgm, Clock and Data are carried on the programmer cable. As soon as the programmer powers up the PIC the PGM pin is floating and the applied ground is acceptable. Clearly, you can not have the PIC already powered, the pin initialized as an output and expect to be able to ground it before the programmer resets the PIC and causes the pin to float. --- In , "Scott Lingerfelt" <slingerfelt@c...> wrote: > > I would like to add ICSP to my project! I am going to setup my header as > seen in this link http://www.melabs.com/support/icsp.htm. My question is > that I am using my PortB 6&7 for outputs connected to an ULN2003, can I also > connect to my header for programming without damaging anything? Should I > add some diodes to the circuit? I am using a PIC16F628 which suggest that I > connect PORTB 4 to ground to stop interference. If I have PortB 4 connected > to the same ULN2003 should I jumper this to ground? > > Thanks in advance, > > ************************************** > Scott Lingerfelt > slingerfelt@c... > ************************************** > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.537 / Virus Database: 332 - Release Date: 11/6/2003

(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )

Sign in

Search piclist

Subscribe to piclist

piclist by Keywords

Ads

Discussion Groups

Discussion Groups | Piclist | In Circuit Serial Programming

In Circuit Serial Programming - Scott Lingerfelt - Nov 11 22:59:00 2003

Re: In Circuit Serial Programming - rtstofer - Nov 12 0:24:00 2003