Advice please - Warning message

[malc-c]

Steve,

Well it must be either something querky with either the programming software or the 18F series of chips (or just the 18F2550)

I tried repeating some of the things here but using a 16F873A PIC (just happened to have a couple in my hobby box - no other reason) I compiled the following code (edited version of your test code)

ADCON1=$0F
TRISB=%00000000                  'set PORTB as all output
PORTB=0

ByteA   var byte
 
main:
    for bytea=0 to 7
        PORTB=DCD BYTEA
        PAUSE 250
        NEXT
    PORTB=255
    PAUSE 250
    goto main

It compiled with out error and loaded without error (using either application, Winpic or PICpgm). This was using the default INC files I also tried my original code (in post 1 I think) and that too loaded fine. But try as I might, even though the programmer, both software and hardware claim to support 18F2550's I can't get it to work with this PIC.

I've yet to breadboard and test the PIC - and I need to swatt up on the datasheet to see what this 16F873A offers, but as I don't need anything too fancy I'm sure it will do just fine (assuming I can get the hardware running)

[malc-c]

Well using the 16F873A I have flashing LEDs so that rules out things like faulty components, or a suspected problem with the breadboard.

Looking at the datasheet, I think the only possible limitations will be the memory for data storage, other than that it has AtoD so I should be able to connect up a music source and get the LEDs to act like a VU meter

[mister_e]

Nice! Depending how fancy you want to be and from what i understand about your project, F873 should be enough indeed. F876 could be the update one.

Gooooood ol' 16F

You said you had 3 18F2550... Microchip demo or not? If they are Microchip demo... well they COULD be faulty... on the other hand i never had any faulty one from microchip myself... Still possible.

Well, since you have something's working... over 40 post and 10 page later but at least somethings work

Good luck!

[skimask]

Have you tried the .1uf across both sets of Vdd & Vss pins? Not on the programmer, I mean right across the pins, right at the PIC, like within a couple of mm of the pins themselves, even if they're only temporary.

I've got a Warp13a and none of my 18F1230's, 18F2550's (basically anything with the 'Nanowatt' feature) will program correctly without those cap's in place, right at the PIC.

I know you've tried the cap's as mentioned in earlier posts, but, I didn't see any mention of being right at the PIC.

JDG

EDIT: Another thought...
A totally seperate issue that has tripped me up with the Warp13a and it's associated software/firmware is various pieces of background Windows software messing with the serial and USB ports. Specifically, all those programs that monitor hardware temperature, voltages, fan speeds, etc. Every time one of those would update, it would cause my programmer to crash, not the firmware, but the actual programmer itself. Dont' ask why...I don't know. Suffice to say, I shut all that crap off when I'm PIC'ing, and all is good.

[mister_e]

Yup and Warp13 is not the only one suffering of those missing or needed caps... some device need it with PICSTART when using the ZIFF socket.

Interesting point about the background Windows Software so far.

One thing i didn't asked to Malcom...

Malcom, are you using a USB to Serial converter or not? I heard that some model may don't work... kind of bad timing, speed issue or whatsoever when using/creating a virtual COM port.

But yeah, it work with some other PIC model...

We can still talk about Ambient light.. neon ballast or incandescent bulb but... i think it's pushing the limit... i remind to have some programming issue with PICSTART awhile back when he was too close of the PIC...

[malc-c]

Hi guys, and thanks for the replies.

Yes I did fit the 0.1uf capacitor as close to the PIC as I could (pins 19 & 20), as well as across the main power rails on the breadboard. The PG-02 programmer is connected direct to Com1 via a standard 9 way serial cable - no convertor is used.

The three '2550's were sample chips from Microchip, I've sinced tried one that I purchased this week from RS and that too shows the same issues, so my guess is that there is something the 18f2550's need (either physical hardware configuration, or software) that either my hardware or the software can't provide. Like I said the 16F873A programmed 1st time and works fine...

I'll have a look at the other chips you mentioned Steve, and maybe a few others. Just need to brush up on my rusty skills and try out some new things in PBP (LCD and A to D )

Whilst agree that after all these posts, and what has turned out to be a long thread we didn't actually resolve the issue, but I did learn from the experience and have a better understanding of what to lookfor and how to edit INC files etc. I just hope that others can also learn from the topics covered in this thread too.

Thanks for your time and input

[skimask]

Yup and Warp13 is not the only one suffering of those missing or needed caps... some device need it with PICSTART when using the ZIFF socket.

Interesting point about the background Windows Software so far.

One thing i didn't asked to Malcom...

Malcom, are you using a USB to Serial converter or not? I heard that some model may don't work... kind of bad timing, speed issue or whatsoever when using/creating a virtual COM port.

But yeah, it work with some other PIC model...

We can still talk about Ambient light.. neon ballast or incandescent bulb but... i think it's pushing the limit... i remind to have some programming issue with PICSTART awhile back when he was too close of the PIC...

I've heard about problems with the USB-serial converters also. Something related to the fact that there was no direct 'ground' between the PC and the programmer as a result.
JDG