Which way next? - K8048/PIC16F84A

Hi Velleman

I’ve just completed building the board and am having some issues getting it going. Here is my setup:

OS = WindowsXP (SP2)
Port = COM1 direct with homemade cable (no USB to Serial converter)
Power supply = 12V/1A
PIC = PIC16F84A
Assembler = MPASM v5.01
Programmer = ProgPic2 v2.6.0 and the latest version of WinPic
ASM file = F84DEMO1.asm

What I’ve achieved so far:
LD7. LD8 and LD9 seem to work as recommended, although LD9 was doing that light blinking thing but seems to have stopped now that I connecting directly from COM1.
I’ve eliminated the USB to serial issue (see above)
I’ve fried the supplied PIC16F627 by trying to load the demo2.asm (there is another post on this forum which talks about this) so am now using a new PIC16F84A
When I run Progpic it says K8048 found, status ok.
When I run Winpic it lets me complete the interface test successfully.

However, when I try and write the hex file from Progpic I get the following error :

"write error at: 0000
wrote 280A
Read: 3FFF "

and when I try and load the file from WinPic I get a list of:

“Verify Error: 000000: read 003FFF, wanted …” errors.

So I need to know which way to turn next so that I can get this resolved and get to bed at a reasonable time. So here are my questions:

From what I have said were do you think my problem might be.

  1. The board/power supply
  2. The software/program/OS
  3. The PIC.

I’ve trawled this forum and see there are issues with all 3.
How can I be sure the board is functioning properly?
Is there an english alternative to circuitsonline.net/forum/user/13539?
Where can I get troubleshooting help on board voltages etc.?
(My knowledge of electronics is fairly rudimentary)
Will the F84demo1.asm work in a F84a?
The progs on the net use the list command (LIST P=16F84a ) but the supplied progs don’t. Where can I find basic guide to the structure of asm files?
Do you have a simple test asm file for a F84a that I could use?

Thanks in advance.
Paul

Paul,

a couple of pointers…apart from the voltage, what type of power supply are you using?

Velleman recommends an unregulated 12 power supply, which will actually output around 15.2v, with the regulation being done on the board itself.

I use a modified PC PSU which gives out a regulated 12v, but it works for me. This is not to say that you should do the same…using an unregulated 12v supply should eliminate this step as a cause of your problem. I say ‘should’, as there have been reports of very noisy PSU’s causing problems and I don’t mean audible noise.

Have you tried disabling ‘Write Config.Word’ in the ‘Write’ options and just using the config in the code that you are writing?

Also, can you please clarify what you mean here:

LD9 is supposed to flash, but only when SW5 is in either the ‘Prog’, or ‘Run’ position.

HTH,

Mickster.

Hi Mickster,

Thanks for getting back to me.

I took your advice and managed to track down a bench top power supply from work and experimented with different input voltages, but still with the same results.

As part of my next strategy, I dusted off an old Windows 95 laptop and installed Progpic2, etc and to my delight, the program downloaded and I was able to run it. I guess my current laptop’s COM port drivers were a bit too advanced for the K8048.

I have read on other posts that there are issues with modern laptops. Is there a guide to the COM port/chipset requirements for the K8048? I’d rather not have this old laptop just sitting there for the purpose of programming my PIC’s.

I then replaced the original power supply and everything still worked as expected.

So, I’m off now to write some assembly code.

Thanks.
Paul

Glad you got it sorted.

Another step to be added to the trouble-shooting guidelines - Port settings/observed voltages…

Have you tried changing any settings relating to the COM port on your original laptop, in order to get the board working properly?

I sorta recall something mentioned somewhere, maybe not on this forum, that later laptops are using lower voltages on the ports in order to preserve battery life. Mine has neither a serial port, nor a parallel port, so I can’t dig out the 'scope to confirm this.

I did read somewhere on this forum the one user had un-ticked the “Use FIFO buffers” and their programmer had worked, so I gave it try but was unsuccessful. I also read that changing these settings made no difference whatsoever.

I’ve also just read the post about running it on a Linux box. Has anyone else had success with running it on Linux, specifically Ubuntu?

Thanks.
Paul