More transmitters driven at the same moment is better.  No phase issues, th=
e wavelength around 800nm=20
You could bounce them off the ceiling of the room for more dispersion.=20

-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of=
 Neil
Sent: Monday, October 17, 2016 11:58 AM
To: Microcontroller discussion list - Public.
Subject: [EE] Multiple IR transmitters for better coverage?

Hi all,

I've got short time to finish up an IR TX/RX system for a Maker Faire proje=
ct.  I'm having some issues getting my IR comms to work reliably due to dis=
tance and angle.

Briefly, I'll have a 4' x 6' playfield with an IR LED mounted centrally
44 inches vertically above the field.  Small cars can be anywhere on the fi=
eld and need to receive commands from that IR emitter.  I've calculated tha=
t max angle is about 41 deg, and distance between transmitter and emitter i=
s 60 inches at that point.

IR comms works fine up to about a 30+ deg angle, so I'm considering 2 emitt=
ers transmitting exactly the same thing at the same time. Would I have any =
issues with this?  And anyone have experience on if it would be better to h=
ave both emitters at the same point, pointed about 20-30 deg apart, or shou=
ld I space the sensors a couple feet apart, so each one covers half the fie=
ld.


Cheers,
-Neil.

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