Trouble with most basic BLINK on PIC 16F819

[Archangel]

Here's some handy links for you

PortA Doesn't Work
http://www.picbasic.co.uk/forum/showthread.php?t=561


Presetting Configuration Fuses (PIC Defines) into your Program
http://www.picbasic.co.uk/forum/showthread.php?t=543

These 2 links should be required reading to register here. IMHO

[confusedperson]

Thanks everyone for responding so fast with such detailed help!! I am at work now but will give these things a shot when I get home, including reading through the docs you linked to.

One question to Steve (mister_e) though: I thought what I was doing with going high and low out on the pin was analog out, no? Or am I confused about what analog/digital means in this case? Does analog give me a potential range of values vs. digital giving me just two (high/low a.k.a. on/off a.k.a. 0/1) values? As I write it out it seems more and more obvious to me...

[confusedperson]

So, I've read through the docs and things are starting to be much more clear, I'm understanding what is important in the data sheet vs. not. I think I'm almost there but what I'm seeing is the led going on once when I power up but then stopping. Does this sound familiar to any of you?

Thanks again for all your help--

Best,
Dave

[mister_e]

Well this doesn't sounds familiar, unless the configuration fuses are not properly programed by your Device Programmer.

Program your PIC, read it back. See if the config fuses stay the same.

You could still post your .HEX file here (change the extension to .TXT), so we could try it world-wide

[Acetronics2]

Hi,

as default OSC comes in HS mode ... did you just try to run your PIC with a simple 4Mhz Xtal and its pair of caps ???

My two cents ...

Alain

[confusedperson]

Hi folks,

I finally figured it out through fastidiously reading through the docs you linked to and testing out all the settings I could. My led is blinking away happily now. It's amazing what a sense of accomplishment such a small thing can provide!

However, I'm having trouble with one other element: whenever I try to load the config fuses in the code I get an assembler error:

@ __config _INTRC_IO & _WDT_OFF & _PWRTE_OFF & _MCLR_OFF & _BODEN_OFF & _LVP_OFF

I'm using MPASM, and so I've checked these against the names used in the PIC16F819 file as described by Melanie here. But whenever I try to compile I get the message

"Error[118] c:\docume~1\dave\desktop\dd_pic\blink.asm 44: Overwriting previous address contents (2007)"

However, if I turn off "Update configuration from file" in the programmer, comment out this line, and set the config fuses manually in the programmer config, I can get it to work. Am I doing something obviously wrong here?

Thank you all for your endless patience and helpful assistance!!

Best,
Dave

[mister_e]

Have a look at post #5 in the thread I posted about the config fuses.
http://www.picbasic.co.uk/forum/show...75&postcount=5

Clear as mud huh?

Don't give up.