PIC16f877-20 to a PIC16f877A I/P Disaster

[cupajoe]

If you use in circuit serial programming then you need to load the bootloader file for the 16F877A -20 as well as selecting the 16F877A.

Hope this helps.

Joe

[andyf]

Hi Joe,

I have to load a what?

:-)

[Bruce]

Have you tried programming this 877A in an EPIC zif socket?

[andyf]

I dont have a zif, its sitting in a solderless breadboard directly in the place where the 16f877 was, I keep trying idea's, swapping them around, reloading the appropriate hex file but still get the error when I verify.

I am using conventional In circuit programming, hardly any components on the breadboard and smooth voltages.

What works perfectly for the 877 does not for the 877A.

Tried erase before write.

Made sure I have the low-voltage programming pin (RB3) pulled to
ground when programming the device.

Above it was suggested about the bootloader, is a bootloader required if using the older in circuit programming or on the 877A must it be used no matter how, just a thought.

Its doing my head in, got a project on the go and cant store the code in the chip :-(

[Bruce]

Try to program it in-circuit without the crystal connected.

Try turning off the EPIC verify option. Then see if your code runs as expected.

Does either work?

[andyf]

Tried it Bruce and it made no difference, am going to cry soon.

[Bruce]

If you turn OFF the EPIC verify option you still get a "verify" error?

[cupajoe]

Hi Joe,

I have to load a what?

:-)

What program are you using to program your PIC? Is it a bootloader?

If you are programming your pic onboard thru a serial cable using a bootloader then you need to load the bootloader software onto your pic. This is a file specific to your pic and its osc setting. This file is usually supplied by the programmer company and its usually stored in a folder with the programming software.

If you are programming your PIC using a serial programmer then the problem may be hardware related. The breadboard could be causing you some problems. I have read of others who said that they had trouble with programming PICs in breadboards.

Regards,

Joe.

[andyf]

Ok, so this is where I got, not far.

I tried everthing and more but still no joy, waisted a lot of peoples time and ended up back to square one sorry and thanks for your help.

I feel there is a problem with these PICs or my epic is failing to store the code in the chip, I tried all night going over and over it then threw the towel in and gave up. I think the only sollution I have is to just use pic16f877-20/p which work fine instead of the pic16f877a i/p which give me problems.

working back using the pic16f877-20/p I have a new problem with ports http://www.picbasic.co.uk/forum/showthread.php?t=1683 any idea's guys