From: Spehro Pefhany
Subject: Re: Best way to power array of LEDs?
References: <7tGLdeAS6fn9EwBv@jmwa.demon.co.uk> <email@example.com> <firstname.lastname@example.org> <email@example.com>
X-Newsreader: Forte Agent 1.92/32.572
Date: Thu, 05 Dec 2002 18:59:56 GMT
NNTP-Posting-Date: Thu, 05 Dec 2002 13:59:56 EST
On Thu, 05 Dec 2002 16:33:44 +0000 (GMT), the renowned Tony Williams
> Are you talking about the chap, (and I prefer to
> remain anon please Speff), who did this stupid perp?
> +Supply---->----/\/\---+-----|>|---- 0v.
> | LED
> PIC port pin-----------+
> Had this brilliant idea that could could turn
> the LED On/Off by toggling the port pin from an
> input, to an output at logic 0.
Aside from the obvious worry if TRIS or PORT latches
get flipped by noise, it should work, assuming
+Supply <= Vdd + 0.3 (except for the funky open
drain output w/o protection diodes that some of them
Though I don't think Vout(low) is guaranteed at
20mA, it should be low enough even for a red LED,
shouldn't it? (at least with the current crop)
"it's the network..." "The Journey is the reward"
firstname.lastname@example.org Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.co