I was up in Selkirk a few weeks back for my niece's graduation from Rensselaer, and I took along a present for my brother Bruce: a transmitter-less battery-less RadioShack "Razer" truck. He has been looking for something to hook up to the Philips LPC-series ARMs he has been playing with, and, for $3 this seemed like the perfect gift.
We pulled it apart, clipped the wires to the receiver board, and started disassembling the motors. The rear motor assembly has two motors; one operates what appears to be a high/low gear shift, and the other is the drive motor proper.
The steering mechanism looked normal enough, but it had a _lot_ of wires going to it: two to the steering motor, and _five_ to what turned out to be a multi-pole rotating switch! Using a meter we were able to determine which wires connected to which, but we haven't been able to make any sense out of _why_ the connections are made the way they are.
We measured the switch with the steering in five different positions: Full Left, Partial Left, Center, Partial Right, and Full Right. The five wires (White, Red, Green, Yellow, Blue) are switched together as follows:
FullLeft: Red-Green, White-Blue PartLeft: Red-Green Center: Red-Yellow PartRight: White-Blue (?? looks like an error) FullRight: White-Green, Red-Blue
Part of it almost makes sense:
FullLeft FullRight
Red----Green ==> Red----\ /---Green \/ /\ White---Blue White--/ \---Blue
Looks like a polarity reverser. But (a) the wires didn't go to the motor, they went to the receiver board, and (b) even if they had, why only reverse the motor at the _ends_ of its travel?
We'd _like_ to use this switch to sense steering position. If anyone can offer any suggestions on how to interpret this switch for use with digital inputs they would be very much appreciated.
Product details: RadioShack Razer Catalog # 60-4134 (on the "licence plate")
Provides some documentation and a parts list, which includes:
MANUAL,SERVICE 60-4134 MS6004134 (part#s, but no manuals) MANUAL,USERS 60-4134 MU6004134
Ah, well. Another week, another mystery.
Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)
-- Never worry about theory as long as the machinery does what it's supposed to do. -- R. A. Heinlein
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