Software Prototype board question

[kamputty]

Hi all,

Sorry for putting a hardware question on this forum, but the ICD/MachX forum just did not sound right!

Okay, I'm not an electronics person, so please excuse the foolishness!

My setup:

#1. Laptop-->(usb)MachX-->Software Proto Board(ICD)
#2. The PIC18f4520 is connected to an RCA cable (sending to TV), both pins C0 & C1 to center pin on rca, and ground to the ground of the rca cable.

This all works. I can display to the TV via the pic.

Now, here is the strange part!

If I disconnect the ICD cable, or the usb, I cannot make the PIC work! It just does not come up.

Now, I took a picdem2 that I have, used the same pic, and same setup, except that there is nothing connected to the picdem2 (just like the proto board), it all works fine! So again, if I use the protoboard without any connections other then power (external connections, the pins are still connected) nothing, dead. The same setup with the picdem2 is fine.

Now, I keep wondering if this is a ground thing?

Did that make sense?



~Kam (^8*

[kamputty]

Okay,

Here are more stats!

Setup:

laptop-->machX-->[any proto board]-->pins c0:c1:gnd to rca cable

Now, If use the CCS Sofware Proto Board, it will not work once I connect ANY pin to the RCA (remember, no ICD cable)

If I use the PicDem2 board instead of the CCS Software proto board, it works just fine...! Same setup, but just a different proto board

Now, if I use the CCS Proto Board, and DO connect the ICD cable AND the machX is connected via USB, it works. If MachX is NOT connected to the laptop, no work.

So my thinking is:

(a). Is there not enough power and it gets the difference from USB?
(b). Is there a ground problem and it gets the difference from USB?

Thoughts?!

~Kam (^8*

[kamputty]

Go it!

Actually, CCS support got it! Thanks!

In the fuses I had "LVP", changing that to "NOLVP" took care of the problem!

~Kam (^8*