Beginner problems with 18F66J50

[prstein]

Have you tried a different "Oscillator Selection"?

Robert

I've now gone and tried all of them again, this time with extended instruction set disabled. No luck. Thanks for trying.

Best Regards,
Paul

[rsocor01]

I've now gone and tried all of them again, this time with extended instruction set disabled. No luck. Thanks for trying.

Best Regards,
Paul

I also see that you don't have a diode in MCRL protecting Vdd from Vpp. From the PIC datasheet, the maximum absolute value that Vdd can take is around 4.5 V. If the programming voltage, Vpp, is greater than 4.5V you might have damaged the PIC by no using a diode.

I don't see anything else that might be causing problems.

Robert

[mackrackit]

The drawing also only has half of the OSC connected. But I am sure that is only on the drawing...

Why not try just for fun, setting the configs not with the programmers software but in the *.inc or code space?

The settings in the *.inc straight from the install for this chip should have you running with a 20 OSC.

Then
DEFINE OSC 48
Me thinks.

[prstein]

The drawing also only has half of the OSC connected. But I am sure that is only on the drawing...

Why not try just for fun, setting the configs not with the programmers software but in the *.inc or code space?

The settings in the *.inc straight from the install for this chip should have you running with a 20 OSC.

Then
DEFINE OSC 48
Me thinks.

Thanks for catching the error in the schematic, but as you surmised the resonator is indeed connected.

I don't alter the inc file because I have no luck figuring out what they should be, at least in this case. I'm happy to try most anything to get this to work...

I tried adding the define (and also several sets of configuration settings), with the same negative result.

Best Regards,
Paul

[prstein]

Thanks to everyone who replied. You were all headed in the right direction. Turned out to be the beta MELabs U2 programming software. For some reason it wasn't picking up the settings in the .inc file. I went back to the earlier version of the programmer software (and had to copy 18F66J50.inc to that folder--not supporting that chip was why I tried the beta download) and everything worked fine.

Now knowing the proper programmer settings I tried the beta again, still wouldn't work. I guess I should report a bug to MEL.

Best Regards,
Paul

[mackrackit]

COOL!

Have you tried setting the configs in code space? Might be a work-around.
http://www.picbasic.co.uk/forum/cont...o-your-Program

[Bruce]

Robert mentioned an important point about the protection diode - I would also take into consideration. It may work for a while, then just fail, if you don't add that diode. It's well worth the expense. Just FYI.

[prstein]

COOL!

Have you tried setting the configs in code space? Might be a work-around.
http://www.picbasic.co.uk/forum/cont...o-your-Program

Thanks Dave. Now that I can start running with this project I will certainly do that.

Best Regards,
Paul

[prstein]

I also see that you don't have a diode in MCRL protecting Vdd from Vpp. From the PIC datasheet, the maximum absolute value that Vdd can take is around 4.5 V. If the programming voltage, Vpp, is greater than 4.5V you might have damaged the PIC by no using a diode.

I don't see anything else that might be causing problems.

Robert

Thanks again, Robert. The ISCP is not providing Vdd for the board. Vdd comes from a 2.5V regulator. I verified with a 'scope that Vdd is not changing during programming. I can see the programming data coming in at 5V, but PORTB is 5.5V tolerant.

Best Regards,
Paul