[mythtv] OT: Question about IR Blaster Circuit

Michael Proctor-Smith mythtv-dev@snowman.net
Mon, 30 Dec 2002 14:50:46 -0800

> -----Original Message-----
> From: mythtv-dev-admin@snowman.net
> [mailto:mythtv-dev-admin@snowman.net]On Behalf Of Jeremy Oddo
> Sent: Monday, December 30, 2002 12:50 PM
> To: MythTV
> Subject: [mythtv] OT: Question about IR Blaster Circuit
> I've got a question about building the IR circuits.
> I am no electronics wizz, so I showed the circuit layouts to my friend.  I
> showed him the IR receiver from http://www.lirc.org/images/schematics.gif
> and the IR transmitter from http://www.blars.org/blarslirc/.  He noticed
> that the receive diagram uses pin 5 for ground, but the transmit diagram
> seems to use pin 5 for power (?).  Again, I couldn't solder my way out of
> a paper bag, so I was wondering if anyone can make sense out of the two
> diagrams.
> If the pin-outs for the transmit circuit are incorrect, what _should_ they
> be?
> Thanks!
> Jeremy

> I don't know about the transmitter, but I just built the receiver
> and I can vouch for the fact that it is spot on! 

Ether it is that there is negative voltage on the serial port, or that
ground is a base point to mesaure above. There is no real "ground" it is
just the voltage level to measure from.