And this is why using the TX/RX lines for a simple on/off signal is far more complex than necessary. Faking a byte requires timing with some precision[1], and that timing is dependant on the current configuration of the receiving system (the baud rate set for the serial port). Using a control line instead of trying to fake a byte is far easier.
Tim
[1] Though not as much precision as proper uart comms, as receiving (say) 00000111 instead of 00011111 is probably OK.
Johns posts are above 95% correct, and when he posts schematics (in ABSE) the look professional (not that i'm an expert)
I'm waiting to hear from the guy who designed the "1388" and "1389" RS232 line driver chips (Jim Thomposon?) ... he posts here (or to other parts of sci.electronics) occasionally.
Bye. Jasen
Joe was the first with insults.
Bye. Jasen
In response to what Jasen Betts posted in news: snipped-for-privacy@clunker.homenet:
Posting blatantly wrong info and claiming to be a 'Professional Circuit Designer' isn't asking for insults?
--- Nope, and neither was my posting:
"I can do that with a 555, two 9V batteries and three discretes, no matter _what_ his system looks like."
when I was describing an easy way to make the required pulse train, but you chose to reply with:
"And you think /that/ is the /simplest/ way? What kind of sledgehammer do you use to crack nuts? Steam-driven?"
Which was clearly the first insult. Plus you didn't come back with something simpler than what I described in order to prove your point, so your retort was just bogus bullshit.
I think what got you steamed in the first place was when you found out you were wrong about:
"No. The easiest way depends on the intended listening device. Catering for all possible varieties and vagaries is certainly *not* the 'easiest way'. That is the *hardest* way."
and decided to get on my case after that.
Oh, well...
-- John Fields Professional Circuit Designer
No, dipshit.
Go away, ESAD!
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