I upload my suggestion to files... http://groups.google.com/group/jallib/web/icsp2.jpg
It's not how I would design it. But it's closer to Microchip recommendations, safer and better and exactly same components :-) On Mar 31, 2:13 pm, "m...@watty" <[email protected]> wrote: > On Mar 31, 2:09 pm, "m...@watty" <[email protected]> wrote: > > > > > According to ALL the Microchip ICSP schematics: > > 1) VPP connects direct to MLCR pin. no resistors or diodes. > > > 2) VPP/MCLR is connected to rest of circuits (reset buttons, VDD, R &C > > reset time constant, what ever you want) via a diode (to block VPP > > > VDD) OR a resistor (to limit VPP to VDD current) AND ALSO the resistor > > OR diode means the capacitor is NOT directly connected to MCLR/VPP, to > > avoid damp rise time of VPP too much. > > > Basic principle. > > > 1) Vpp pin connects DIRECT to MCLR pin > > > 2) have what you like for reset circuit, but either a diode or > > resistor or something to limit OR block VPP -> VDD current flow and > > ensure rise time of VPP is not compromised. > > > so on your schematic dump the series diode on VPP. > > disconnect MCLR from everything and connect it direct to VPP and other > > end of the 1K ohm resistor. > > Then the circuit meets Microchip specs. > > > See help file of pickit 2 in MPLAB readmes, or Pickit 2 or 3 user > > manual under ICSP. > > use the diode you took out of vpp -> 1k -> Mclr to go from c4 to Vdd/ > 5V as a clamp. Otherwise when serial port goes --|_|--- the rising > pulse can be enough to put PIC into programming mode. I've seen > program corruption with Vpp spikes on MCLR if the data & clock pinds > RB6/RB7 happen to change too. -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
