OPTICAL SENSORS???????????????????


OK Find page 12 of the 2002 competition manual and look at the diagram for the optical sensor. Also, open up to page 30 of the Innovation FIRST control system users manual. The diagram shows an example and if you refer to the control sys manual table 7.8 you see the pins used are #3 for a ground (but you could use ANY pin marked Ground on the table instead, they are all connected to each other.) The example also uses pins 15 and 16. The important thing here is to use a related pair of pins. F.I.R.S.T. requires both outputs of the sensor to be connected so even if you don’t need the opposite signal, at least for the moment, you have to wire it in anyway. Solder the Blue wire to the selected ground pin in the 25 pin connector that came with the F.I.R.S.T. parts kit (the pins are numbered on the connector). Likewise, solder the Black wire to the pin you want to use for “beam detected” and solder the White wire to the pin for “NO beam detected.” (The robot contoller looks for a grounded output for “on”) Finally, you can strip the brown wire out of the black plasic sheathing and connect to the fused +12 output of the fuse panel as shown on page 8 of the competition manual. If you need to extend the wire use 16 AWG wire. Modify your program and you’re in business…

Best Wishes

Steve Alaniz

“You’d waste technology on a machine that folds laundry?” - Ted Forth

The wiring diagram is on the side: beside the plus-in-a-circle is a color (probably Bn = brown), beside the minus-in-a-circle is another (possibly Bu = blue). The other two colors (are they black [Bk] and white [W] ?)are shown connected through a switch to the minus-in-a-circle. One of the switches is closed, one is open; this represents the condition when the eye detects no returning light.

The plus-in-a-circle goes to +12V, via a circuit breaker. The minus-in-a-circle and one of the switches go to the digital input connector (or your circuit board. If to the digital connector of the RC, then the minus-in-a-circle lead goes to ground, and one of the other leads goes to a digital input pin (see your control system manual). I say one of the leads because both change on detecting light, so it is up to you which operation you want: 1 for light or 1 for dark. Try one, if you don’t like it, change it.

I can’t tell you the correct colors because the sensors were not in our kit, but I have one of last year’s, and the colors are somewhat standardized in the industry.

BTW, be careful, they’re not switches, they’re transistors.