IR without EDU '04 Robot

[Bill Hnath]

Our team was didn't receive an '04 EDU bot since we got one last year. Is it possible to run IR on the old EDU or a previous control system? Tried running the default code on them but of course it proved futile. Any tips would be much appreciated. Thanks in advance

-Bill Hnath

[sanddrag]

You should have still received the new EDU controller to use with the old EDU motors and mechanical pieces. Check the Innovation FIRST website if you don't know what it looks like.

Either you need to talk to whoever handles shipments on your team or talk to whoever handles shipments at FIRST.

[Mark McLeod]

Originally Posted by Bill Hnath

Our team was didn't receive an '04 EDU bot since we got one last year. Is it possible to run IR on the old EDU or a previous control system? Tried running the default code on them but of course it proved futile. Any tips would be much appreciated. Thanks in advance

-Bill Hnath

You cannot use prior years controllers, but you can power the beacon from the FRC. Your team wouldn't receive a full EDU kit, but they sent older teams just the new EDU controller. Small box 6.5" x 4" x 1" Fragile sticker.
If you want to drive with it however that will be more difficult. You'd need a long cable and be able to keep it out of the drivetrain.

There's some code in this thread http://www.chiefdelphi.com/forums/showthread.php?t=24727.

[Dale(294engr]]

Construct a two 555 timer chip circuit (one 7555 CMOS dual timer pkg)

(see ICM 7555 data sheets for astable variable duty & 50-50 application info)

to drive the IR Beacon (see my previous post)
One timer for 100Hz 5% duty (or 95%) driving
2nd timer at 50-50 duty, 40kHz, driving FRRC MOSFET & IR LEDS.
(can add a pot to vary 40lHz +-5Khz to test 4840 rcvr sensivity at distance)

suggest 2 IR diode series strings 16 ohms each,
driven by FRC logic level MOSFET, 4.5-5v battery supply

or one string of 4 for use with 7.2 (to 8v rechargable)
(use IR LED Vfwd=1.34v for calcs Rlimit=V[supply-Vled(s)]/I,
I = 100-200mApk)

note batteries will last much longer with this CMOS driver
and low average power of series LED strings than
EDU (drqws ~.1A constant) on 800mAHr niCads
driving 4 parallel strings.

IR LED current limit resistors can be tailored
for various optical output powers
~100 mA to 200 mA pk per LED or more
(spec sheet up to 1A but much care/skill/knowledge req'd at high current)

regards, Dale 294