Can't set 38400 baud @ 48Mhz

[b1arrk5]

Thanks guys. I have ruled out my programmer, crystal, etc. due to the fact that I can program and run Steve's USB demo program no problem. In fact what started all of this is that I tried to add a serial port connection to his program to see if I could extract data via the serial port, and put it out the USB port. I did copy and paste from Steve's Pic Multicalc program. If I set my OSC define to 20 Mhz, and set up the programmer for HS instead of HSPLL, I can get 38400 out, and if I insert a 16f877 into the same board I can get 38400 out. It's just when I set the OSC to 48 Mhz that I get the argument out of range warning. I'm using a MELABS Labxusb board, in fact I have two of them, and I have tried both. I'm using MELABS USB serial programmer, I have the latest patches installed from their website, I tried the USB programmer Beta version as well. I even tried installing all of the software on a different PC. What is weird is that I can burn Steve's USB demo ok, and I can do the USB mouse demo no problem, or like I said, I can drop down to 20Mhz ok. I'm still not ruling out my doing something stupid............

Keep warm in Montreal and North Dakota. It's getting colder here in Pennsylvania, but Saint Patty's day is coming!

Many thanks again,
Jerry.

[mister_e]

it's not too cold in here, but we had 50-60 cm of snow since thursday night, and we're suppose to have 10-20 more tomorrow or tuesday Bah, could be worst!

You have a strange problem, i've attach a working .HEX code: USART, 38400 Bauds, 20Mhz crystal, send string loop. nothing fancy.

Now if you dump it directly to your PIC and it's not working... it's because of the Melabs Programmer. Obviously, if it's working, it's down to V2.46... which may explain this weird warning 202... who knows?

[b1arrk5]

Steve,

Como ca va? Tres bien! Forgive my spelling, but your hex file loaded and works perfectly! This means that I have my programmer etc. set correctly. Just two quick questions then; a) are you using PBP 2.47? b) would you please try adding this to your USB demo program and see what happens. I placed these right after the Define OSC 48 line.

RCSTA = $90 ' Enable serial port & continuous receive
TXSTA = $24 ' Enable transmit, BRGH = 1
SPBRG = 56 ' 38400 Baud @ -0.16%
SPBRGH = 1
BAUDCON.3 = 1 ' Enable 16 bit baudrate generator

cren var rcsta.4
hserout ["Yes we have no bananas!",13]

When I take these lines back out the program compiles fine. The good news is that I've almost memorized the 18f4550 datasheet this weekend! I also tried adding this;
asm
mov w,1
movlw spbrgh
mov w,56
movlw spbrg
endasm
right after the _config portion of the program, but no luck. I'm don't do assembler, but I read Myke Predko's book, and can follow along.

Thanks again, and don't shovel too much snow!

Jerry.

[Darrel Taylor]

Maybe I'm reading the PicMultiCalc wrong but...

With BRGH = 1 (TXSTA = $24), and BRG16 = 1 (BAUDCON.3)

Don't you need SPBRG = 312

[Darrel Taylor]

Doh!, nevermind.

Got confused with SPBR<G:H> notation.

Lowbyte = 56
Highbyte = 1

[mister_e]

Como ca va? Tres bien! Forgive my spelling,

Ca va très bien you spelling is not that bad. Como=Comment

but your hex file loaded and works perfectly! This means that I have my programmer etc. set correctly.

Woooohooo!

a) are you using PBP 2.47? b) would you please try adding this to your USB demo program and see what happens. I placed these right after the Define OSC 48 line.

RCSTA = $90 ' Enable serial port & continuous receive
TXSTA = $24 ' Enable transmit, BRGH = 1
SPBRG = 56 ' 38400 Baud @ -0.16%
SPBRGH = 1
BAUDCON.3 = 1 ' Enable 16 bit baudrate generator

cren var rcsta.4
hserout ["Yes we have no bananas!",13]

Yes i use PBP 2.47, and your lines will work no problem.

Thanks again, and don't shovel too much snow!

i'll try


EDIT: i'll change the PicMultiCalc display stuff.. it's really simple and i agree, it will be easier to read.

[b1arrk5]

I called MeLabs this morning as soon as they opened, ordered the upgrade, and they shipped it this afternoon. Thanks for all your help. I'm curious though that Darrel got it to compile ok with 2.46, but maybe it has to do with the temperature. I think you and I should go to California and investigate!
Thanks to all of you for your kind assistance.

Jerry.

[mister_e]

You're welcome. in meantime, i've did the promised change to the PicMultiCalc

You can download it at the usual place
http://www.mister-e.org/pages/utilitiespag.html

[Darrel Taylor]

b1arrk,

It's good to have the upgrade.

But for future reference, I'd still like to figure out what's going on. And I'm still not sure it will solve your problem.

Can you go back to the .LST file again? Search for [202], and post the 5 or 6 lines following the error.