[SOLVED] pic12f508 and pic16f57 unable erase with diy pickit2

[suresh269]

Hi,
some times ago i made by myself a diy pickit2 clone which i found on talking electronics web site.i used to program pic16f628a and pic16f54 without any problem now.but last week i decide to program pic12f508 and pic16f57 and blank ic's are programmed without any problem.but when i tried to erase after device not erasing at all(when press blank check displaying device is not blank ,when read, old hex file still there).then i erased them using my old jdm programmer and checked them in pickit2 clone again and now it's show device is blank.after that ic's can program with new code without any problem.i measured vpp = 12.3v and vcc = 5.1v.please help me to identify the reason.thanks

 

[ucanel]

Can diy pic programmer program a code protected pic?
If it isnt, you may suspicious about supply voltage is not enough
from diy programmer to pic,
i had encountered this problem.

But i think you need to ask this to developer of the programmer.

Also i think building a programmer is waste of time,
you never can be sure is it working properly or not.

 

[suresh269]

Can diy pic programmer program a code protected pic?
If it isnt, you may suspicious about supply voltage is not enough
from diy programmer to pic,
i had encountered this problem.

But i think you need to ask this to developer of the programmer.

Also i think building a programmer is waste of time,
you never can be sure is it working properly or not.

Thank you for reply .
yes ,i can reprogram pic16f628a and pic16f54 code protected too.no issues for them.

 

[ard]

Try the Vpp-before-Vdd option on your Pickit2 software.

Might solve your problem.

Regards,

Anand Dhuru

 

[suresh269]

dear ucanel and Anand Dhuru,thanks for supportive information to my problem.replaced VDD safety resistor 470 ohms to 100 ohms in series with schottky diode.all pic's i'm using can program now.

thanks

 

[ucanel]

Thanks for feedback,
glad you got it to go.