The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Matt Foster"
Subject: Re: RS232 newbie - in need of assistance!
X-Newsreader: Microsoft Outlook Express 6.00.2720.3000
Date: Sat, 4 Jan 2003 00:48:34 -0000
NNTP-Posting-Date: Sat, 04 Jan 2003 00:48:28 GMT
Organization: blueyonder (post doesn't reflect views of blueyonder)
A loyal source of tips and tricks :)
As far as resistors go, check
and compare it to
See which one floats your boat, if any.
I think I have the pins right now?
"Michael F. Coyle" wrote in message
> "Matt Foster" wrote in message
> > ok
> > http://matthewfoster.myby.co.uk/lousyattempt2.jpg
> Hi again.
> 1. I wouldn't recommend 5.0688 MHz clock frequency. See my reply
> for details.
> 2. On the 628, the UART transmit is on pin 8 (overrides RB2); receive is
> pin 7 (overrides RB1). If you use the built-in UART you will have to move
> the inputs on those lines elsewhere. Perhaps use RB3-7 (pins 9-13).
> 3. Some posters have suggested not connecting the receiver since you are
> just sending data to the PC, not the other way around. I would suggest
> keeping it connected; after all, we're only talking two wires here. And
> makes the design a little bit more versitile in case you want to keep
> playing with it after your assignment's done. The hardware is already
> there, why not use it?
> 4. My contribution to The Great Resistor Controversy. The other poster
> a point about the possibility of an input pin inadvertantly becoming an
> output and possibly shorting out when the button is pressed. Taking that
> into consideration, here's what I'd do: enable the PIC Port B weak
> and on the pin, connect each switch to ground through a 1K resistor.
> case sceanario: if the input accidently becomes an output and that output
> wants to be high and the switch is closed, the port sources only 5 mA --
> sweat. As an input, if the switch is open, the internal pullup pulls the
> pin high. If the switch is closed, then a resistive divider is formed
> the internal pullup (about 25K and the external 1K. The voltage on the
> input pin is about 0.2 V, a nice good "0".
> 5. You're getting lots of good advice from the group -- some of it
> contradictory. Hang in there.
> - Michael
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.434 / Virus Database: 243 - Release Date: 26/12/2002
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup