MS QuickBasic & PIC16F84A

I'm having a problem and it's driving me bonkers! I have a very simple QuickBasic program running on my laptop:

' Open communication channel to COM1 at 9600 Baud.
OPEN "com1:9600,n,8,1,cd0,cs0,ds0" FOR OUTPUT AS #1

'---- Default Settings ----
byte = 85 ' BIN %01010101

'---- Body ----
MainLoop:
INPUT "Just hit RET.", CHAR$
PRINT #1, byte;
GOTO MainLoop:

The program is supposed to send decimal-85 out of the COM1 port every time I hit return. OK, fine. It seems to work, and yes, I know I'm not closing the COM port.

The PIC is running the following program:

include "modedefs.bas" ' PIC is 16F84A
Sdata VAR PORTA.4 'serial input on pin RA4
CHAR VAR BYTE
TRISA = %00010111 ' set PORTA pins RA0-RA2, and RA4 to INPUT
TRISB = %00000000 ' set PORTB pins to output
PORTB = %00000000 ' Clear port B

main:
serin Sdata, N9600, char ' input byte
PORTB = CHAR
goto main

OK, that looks pretty straightforward, too! The problem is, the PIC thinks it's receiving decimal-32 (ASCII character for a space). Huh?? Can anyone explain why I'm getting decimal-32? I presume that the PC is sending 85 first, and 32 second, but I sure don't see how or why!

Jeff

OMG!

Quickbasic, haven't used that in so many years. Just went down memory lane googling for an answer here. Can't really says it's an answer or not, but here's a few things I found.

Every example I found for OPEN looked like this

OPEN "COM1:9600,N,8,1,CD0,CS0,DS0,OP0" FOR OUTPUT AS #1

Couldn't for the life of me find out what the extra OP0 is for??

Then the PRINT statements would correlate to this...

PRINT #1, CHR$(85);

-- OR --

PRINT #1, CHR$(byte) ' for your program.
<hr>
On the hardware side, the PC puts out TRUE RS-232, but your PBP program is expecting Inverted RS-232. Can I assume you only have resistors in-between the PC and PIC? Or, is there a MAX232 (or equiv.), in which case you would need T9600 instead of N9600.

.

Hi Darrel,

I just had a Homer Simpson moment (Doh!) Yup, that was it! Yeah, I haven't used QuickBasic in a while either (could ya tell?)

Anyway, thanks for the help!

Jeff