UART vs software RS232

[Michael]

So if the modules are asking for CMOS UART in the data sheet, then you don't see a problem with a direct connection from the PIC pins using software RS232?

[Normnet]

The difference may be if signals are inverted or not.
If using SEROUT try HSEROUT.

Norm

[Michael]

I'll try inverting -- that option may be on the module in configuration -- like I say the hardwired connection is fine.

Pardon my lack of knowledge on the matter but what exactly is the difference between
software serin and serout, hserin etc and the UART?

I know the good thing about the UART is that it can run in the background but other than that, what are the differences?

Thanks kindly.

[Normnet]

The USART is hardware, is faster (115.2k baud), has a buffer but is not capable of inverting to eliminate an RS232 driver.

If using SEROUT try inverting or non inverting as per the table in PBP help.

Which command for RS232 are you using?

Norm

[Michael]

By command you mean 8N1?

I'm only using 1200 baud.

So what is Hserin and hserout? I'd still like to know the difference between software generated RS232 and "hardware" RS232.

Just the basics of what is going on.

I'll figure out my problem.....might have to unpack my scope. (wherever it is).

[Normnet]

QUOTE "By command you mean 8N1?"
I mean statement: SEROUT?

Software RS232 can be inverted/non-inverted in software.
Hardware cannot.

SEROUT PORTB.7,1,["START",13] '1200 true
SEROUT PORTB.7,5,["START",13] '1200 inverted

Norm

[Archangel]

QUOTE

SEROUT PORTB.7,<font color=red>1</font color>,["START",13] '1200 true
SEROUT PORTB.7,<font color=red>5</font color>,["START",13] '1200 inverted

Norm

RTFM applies here, in the serout and serout2 sections, you will discover " MODE ", now when using <font color=red>SEROUT</font color>, if you <font color=blue>INCLUDE "modedefs.bas"</font color>, you can specify the mode as in below:

SEROUT PORTB.7,<font color=red>T1200</font color>,["START",13]  '1200 true
SEROUT PORTB.7,<font color=red>N1200</font color>,["START",13]  '1200 inverted