PicKit2 Clone

[vlad777]

**broken link removed**
**broken link removed**


I made this pk2 clone by schematics from blueroomelectronics,
but made my own pcb layout.
(I must critisize leaving out aux pin 6; it's only 2 resistors plus
and I realized that it has it's use only after darn thing was made.)

So I have only two pics to test this board with.
With pic16f84 both fast and normal programming works.
With pic16f628a only slow programming works.

I have noticed that 84 draws 45uA on Vpp pin and 628a draws 3mA on Vpp pin.

Can you tell me how to make fast programming work?

Many thanks.

 

[vlad777]

OK so I hooked up my DMM and measured frequency on clock pin, and here is what I get:

PIC16F84A FAST 60KHz (max)
PIC16F628A SLOW 100KHz (max)

Can someone tell me what is the maximum frequency used by pickit2 on clock data and aux programming pins?

Many thanks.

EDIT:

OK so either:

1)Transistors are too slow
2)Too much capacitance in traces/protoboard
3)High frequency noise from switching PSUs or radio

84 always works but 628 doesn't