TTL to RS232
Archiver
Posts: 46,084
Again on the subject of Oopic controller, its serial abilities are
restricted to TTL and must be converted to RS232 to be able to talk to
serial devices such as serial LCD's etc. They suggest using the
SN75188 or the MAX203 or MAX232. Anybody can explain why this
conversion is needed and sample circuits to follow?
Who would sell the MAX232? I couldn't find the chip at Jameco.
Al Najjar
restricted to TTL and must be converted to RS232 to be able to talk to
serial devices such as serial LCD's etc. They suggest using the
SN75188 or the MAX203 or MAX232. Anybody can explain why this
conversion is needed and sample circuits to follow?
Who would sell the MAX232? I couldn't find the chip at Jameco.
Al Najjar
Comments
At 06:47 PM 6/22/2001 +0000, you wrote:
>Who would sell the MAX232? I couldn't find the chip at Jameco.
_________________________________
Mike Walsh
walsh@i...
>Maxim
>
>At 06:47 PM 6/22/2001 +0000, you wrote:
>
> >Who would sell the MAX232? I couldn't find the chip at Jameco.
>
>_________________________________
>Mike Walsh
>walsh@i...
>
Jameco stocks 3 different versions of the MAX 232. They are on page 11 of
their Catalog No. 211, bottom right corner of the page.
You might want to look at the MAX 233CPP. Does the same job but doesn't
require
the external caps.
Bill Jones, CSRE, CBNT
Station Engineer
KALX-FM
510-642-1111
just like a gender changer. We use them for bar code to PLC conversion.
Sorry, dont have the web site in front of me.
walsh@caltech
.edu To: basicstamps@yahoogroups.com
cc:
06/22/2001 Subject: Re: [noparse][[/noparse]basicstamps] TTL to
RS232
02:50 PM
Please
respond to
basicstamps
Maxim
At 06:47 PM 6/22/2001 +0000, you wrote:
>Who would sell the MAX232? I couldn't find the chip at Jameco.
_________________________________
Mike Walsh
walsh@i...
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Original Message
> A company called Black Box (no kidding) sells a TTL to RS232 that looks
> just like a gender changer. We use them for bar code to PLC conversion.
> Sorry, dont have the web site in front of me.
> >Who would sell the MAX232? I couldn't find the chip at Jameco.
get free samples there, since this is the manufacturer's website.
>
> Who would sell the MAX232? I couldn't find the chip at Jameco.
>
Looks like Newark, DigiKey and Allied all carry it. You can get a
list of who sells what using this site:
http://www.findchips.com
Someone posted this URL a while back. Very handy.
SD
--
/===================================================================\
| Steve DeGroof (http://degroof.home.mindspring.com/) |
\===================================================================/
http://www.al-williams.com/awce/rs1.htm
Your original question was why do you need it... the RS-232 standard calls
for +/- voltages, but TTL is 0 to 5V. A converter allows you to shift the
voltages to the proper levels. A chip like the MAX232 (which is what the
RS-1 uses) uses a capacitor charge pump to generate the correct voltages
from a single 5V supply.
Regards,
Al Williams
AWC
* Floating point A/D: http://www.al-williams.com/awce/pak9.htm
>
Original Message
> From: brownstamp@y... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=guNmEXPjt1i3uzz75EVmM6__eVWdzdQ0XBGd3Od2Vu8bbj7VAx2xeTE1v_NHjbzHt6W-Tr7pNyQpkboOCv4C]brownstamp@y...[/url
> Sent: Friday, June 22, 2001 1:47 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] TTL to RS232
>
>
> Again on the subject of Oopic controller, its serial abilities are
> restricted to TTL and must be converted to RS232 to be able to talk to
> serial devices such as serial LCD's etc. They suggest using the
> SN75188 or the MAX203 or MAX232. Anybody can explain why this
> conversion is needed and sample circuits to follow?
>
> Who would sell the MAX232? I couldn't find the chip at Jameco.
>
>
>
> Al Najjar
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed with. Text in
> the Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>