Electrical

[Wil Wheaton]

I understand the concern with "arbitrary" light sources and the burden on inspection. This is the primary reason I was asking for an allowance specifically for ground line detection in which case the orientation would be ground facing and the sensor components nearly identical to already approved active light sensors.

I think classifying the only difference as "form-factor" is understating the problem. For example my primary motivation is actually cost. The EOPD sensor isn't for line detection but its much better at it than LEGO light sensor ... however the cost is prohibitive to buy enough to make a high resolution array. Even a modest 5 unit array @ $50 / unit = $250. In contrast doing the same thing on a proto board with the *same* IR TX/RX components is around $1 / unit. Even if we used the much less effective lego light sensor its still $20 / sensor for $1 in parts.

Sorry for being long winded, your initial answer seemed pretty resolved so I doubt I've changed your minds ... so an actual question:
Can we use the approved lego/hitechnic active light sensors connected to a prototyping board?

The current rules allow only visible light LED's to be attached to the prototyping board. The LED's in the active light sensors are IR emitters. Even if they were allowed, the current draw limit of the prototyping board (20mA for 3.3/4.3v supply and 12mA for 5.0/9v supply) would likely be exceeded.

[Professor Proton]

May teams use the NXT Light or EOPD sensor connected directly to the NXT in conjunction with IR receivers mounted on the approved prototyping board?

Yes, so long as no other rules are violated.

[Professor Proton]

May teams use a small terminal block for power distribution between the power switch and motor/servo controllers?

Terminal Blocks are NOT allowed.

[Professor Proton]

May we use current sensors to monitor motors or servos as long as the sensor circuit is not able to cause, prevent or alter current flow to the motor/servo.

Current Sensors are NOT allowed.

Allowing Current Sensors between a motor/servo controller and a motor/servo is an interesting request that merits further evaluation. Before allowing Current Sensors, we need to check with the manufacturers, select sensors, conduct tests, etc. For these reasons, it is not feasible to allow Current Sensors this season.

[Wil Wheaton]

We ordered four 180 degree servos from Lego Education PN 739080 and we received two Hitec HS-475HB and two Hitec HS-485HB servos. Are both approved servos?

Please see post #6 in Parts and Materials.

[Raj]

Regarding <R5>b.8.
No more than one (1) HiTechnic 9-volt Battery Box that is sold as part of the NXT Sensor Multiplexer set may be used. It may be used only in conjunction with and to power the NXT Sensor Multiplexer(s).

This clearly states that only 1 9-volt Battery Box may be used but implies that multiple NXT Sensor Multiplexers may be used. However, the battery boxes, at least as currently being shipped by HiTechnic, come with the battery box "hard-wired" to the Sensor Multiplexer. Is it therefore legal to modify the Battery Box / Sensor Multiplexer wiring to attach and drive multiple Sensor Multiplexers from a single Battery Box. Or would you consider changing the rules to allow 1 9-volt Battery Box per Sensor Multiplexer?

A: More than 1 Sensor Multiplexer (S-MUX) is allowed. 9-volt Battery Boxes must be paired with their associated Sensor Multiplexer and cannot send power to any other device on the robot (Rule <R5>b8). So if more than 1 S-MUX is used, then more than 1 Battery Box can be used to power the additional S-MUX.

[Professor Proton]

Is it allowed to attach a reed switch to a robot to use as a touch sensor to detect the magnetic baton?

Yes, with the following constraints:

1. The reed switch is used in conjunction with the HiTechnic Prototype Board and not connected directly to the NXT nor the HiTechnic Sensor Multiplexer.
2. The reed switch does not contain mercury.
3. The body of the reed switch is not glass.

[Professor Proton]

The HiTechnic solderable prototyping board is no longer made. Can we put components on a separate board and solder the board to the solderless prototyping board?

Yes, teams may put components on a separate board and solder the board to the solderless prototyping board.

A replacement for the solderable prototyping board will be available on the HiTechnic web site soon.

[Professor Proton]

Our robot has a long pivoting arm with an NXT motor at the end.
The longest NXT cable will not reach from the NXT to the Motor and still permit full arm movement.
I can't locate any cable extenders or couplers on the LEGO or Pitsco site.
Is there a permissable way to extend the NXT cable, or can we fabricate our own longer cable?

Or are we just plain "out of luck"?

Thanks.

Rule <R5>b9 allows any LEGO Aprooved NXT extension cables. Approved cables are currently only available from LEGO and and HiTechnic. See the link below for an example:

www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=NWS1000

[Sheldon]

We searched all over the web and found only one company that would make a custom USB cable as short as 4"

We tried to splice one ourselves, but USB is double shielded, has nylon stress runners, very fine wires, and very critical tolerances (electrically). So we just folded one up and zipped it.

But if you have an extra $50 dollars you can get a cool short cable. The company also has USB cables with right or left angled connectors. Very handy!

http://www.usbfirewire.com/custom-usb-cable.html
http://www.usbfirewire.com/custom/Custom_USB_FireWire_Cable_Design_Tool.html

Note that TechBrick has nothing to do with vendor nor any business relationship of any kind. It's just another resource if you have extra money to spend.

Thank you for sharing this information. Remember that it is illegal for teams to make or modify their own USB cables.