Sending text via the serial port

[Darren]

OK, I have no idea where to start with this and am looking for some
guidance on how to go about it.

Basically I want to send predefined text to my PC via the DB9 serial port
when a button is pressed, there are several different strings of text
varying in length from 4 to 8 characters (although they could be all the
same length if it helps) and each one is sent when its corresponding button
is pressed.

I'd also like to include a small 1 or 2 line LCD screen to recieve
responses to the sent text, the only thing that would be recieved is text
to be displayed.

What is the best way to go about this and what are the best components to
use.

Thankyou.
Darren

 

[John Larkin]

On Wed, 15 Dec 2004 19:37:31 -0700, Jim Thompson
<thegreatone@example.com> wrote:

On Wed, 15 Dec 2004 21:30:31 -0500, w_tom <w_tom1@hotmail.com> wrote:

Notice the step by step process. Break the problem down
into parts, solve each part, then slowly expand the solution
to include your final design. Its how engineers think - first
breaking the problem down into parts. That alternative is a
massive one time solution that could leave you spinning wheels
in frustration.

[snip]

"Step by step". Extraordinarily well put! It is refreshing to
observe some real engineering thought! My compliments!

...Jim Thompson

Um, not to change the subject, but some guys are top-down designers
(or programmers) and some are bottom-up. Personally, I'm a sort of
all-over-the-place designer; I don't usually even know what I'm trying
to do until it's halfway done, and I keep changing both structures and
details until I like it. That doesn't work as well, of course, in team
designs.

John

 

[martin griffith]

On Wed, 15 Dec 2004 19:36:44 -0800, in sci.electronics.design John
Larkin <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

On Wed, 15 Dec 2004 19:37:31 -0700, Jim Thompson
thegreatone@example.com> wrote:

On Wed, 15 Dec 2004 21:30:31 -0500, w_tom <w_tom1@hotmail.com> wrote:

snip

Um, not to change the subject, but some guys are top-down designers
(or programmers) and some are bottom-up. Personally, I'm a sort of
all-over-the-place designer; I don't usually even know what I'm trying
to do until it's halfway done, and I keep changing both structures and
details until I like it. That doesn't work as well, of course, in team
designs.

John

I think its better to call "all-over-the-place designer"

Lateral Thinking




martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.

 

[John Woodgate]

I read in sci.electronics.design that martin griffith
<martingriffith@yahoo.co.uk> wrote (in <fmm2s0tpmhtnvck6ebve8hpttkj7spcn
92@4ax.com&gt about 'Sending text via the serial port', on Thu, 16 Dec
2004:

I think its better to call "all-over-the-place designer" Lateral
Thinking

'Lateral' as in 'lateral PNP'? Slow, with poor gain?
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[martin griffith]

On Thu, 16 Dec 2004 10:05:22 +0000, in sci.electronics.design John
Woodgate <jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that martin griffith
martingriffith@yahoo.co.uk> wrote (in <fmm2s0tpmhtnvck6ebve8hpttkj7spcn
92@4ax.com&gt about 'Sending text via the serial port', on Thu, 16 Dec
2004:
I think its better to call "all-over-the-place designer" Lateral
Thinking

'Lateral' as in 'lateral PNP'? Slow, with poor gain?
In LT's AN83, about LDO's, on the last page Guru Jim Williams put in a

cartoon
"Speak Softly and carry a Big PNP"

I rest my case


martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.

 

[Darren]

Tim Wescott <tim@wescottnospamdesign.com> wrote in
news:10s1moefdq4bbe@corp.supernews.com:

Darren wrote:

A small microcontroller like an AVR, PIC, 8051, etc. and an LCD
module.
Parallax (http://www.parallax.com/) either has a Basic Stamp with an
LCD module or they have a stick-on LCD module for a Basic Stamp.

Judging by your question you are very new to this: Parallax is
probably the way to go -- and sci.electronics.basic may be the better
newsgroup.

Thankyou for all the replies, I forgot to mention that I'm in the UK, do
you know of any websites that stock these components?

Thankyou

 

[Darren]

Tim Wescott <tim@wescottnospamdesign.com> wrote in
news:10s1moefdq4bbe@corp.supernews.com:

A small microcontroller like an AVR, PIC, 8051, etc. and an LCD
module.
Parallax (http://www.parallax.com/) either has a Basic Stamp with an
LCD module or they have a stick-on LCD module for a Basic Stamp.

OK, forgetting about the LCD screen for the time being, how easy/difficult
would this be.to create, is the microcontroller the only bit required to
send serial formatted data through the com port? Or does this need timers
and other stuff between the comm and microcontroller.

I suppose what I'm asking for is a diagram to show how to link it all
together. I think I can program the chip to send the serial data.

Thanks

Darren

 

[Darren]

Tim Wescott <tim@wescottnospamdesign.com> wrote in
news:10s4bb7am1qj6ea@corp.supernews.com:

Darren wrote:
Tim Wescott <tim@wescottnospamdesign.com> wrote in
news:10s1moefdq4bbe@corp.supernews.com:


You should be able to generate the correct serial signal out of the
microprocessor, either because you're wise enough to choose one with a
UART or because you're clever enough to bit-bang the PIC. To go from
there to RS-232 you need a logic-to-232 converter such as the MAX-232
or similar.

Perhaps you should look around on the web for projects that happen to
use PICs; there will be complete sections of schematics that you can
copy.

Thankyou very much, you've given me a place to start and hopefully continue
from , much appricated.

Darren

 

[Ken Smith]

In article <10s4bb7am1qj6ea@corp.supernews.com>,
Tim Wescott <tim@wescottnospamdesign.com> wrote:
[...]

microprocessor, either because you're wise enough to choose one with a
UART or because you're clever enough to bit-bang the PIC. To go from
there to RS-232 you need a logic-to-232 converter such as the MAX-232 or
similar.

I think Digikey carries the LT1081

Doing a bit-bashed RS-232 transmit is quite easy. The receive is a bit
harder because of the need to sync to the center of the incomming bit
stream.



BTW: You forgot to add "or both" in the above. I know of 2 cases where a
micro with a UART was also programmed to bit bash a serial port.

One was a 6800 development board with debugger software. They left the
UART free for the developer to use.

The other was a case where I needed 2 UARTs.

--
--
kensmith@rahul.net forging knowledge