 | | Re: Ultrasonic sensor interactions
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The problem here is the management of a single shared resource, i.e. the air through which the ultrasonic signals travel. The lack of a Bluetooth broadcast mechanism makes the implementation of a conventional resource locking system difficult, but (...) (19 years ago, 21-May-06, to lugnet.robotics, FTX)
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| | Re: Ultrasonic sensor interactions
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(...) This is a great idea except for one very important item: there is no such thing as a broadcast message (ie: a message sent to everyone) using Bluetooth. So for any such system to work, each robot has to know about every other robot, and send (...) (19 years ago, 21-May-06, to lugnet.robotics)
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| | Re: Ultrasonic sensor interactions
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(...) The problem with that is that both NXT machines may be listening. Neither hears anything - so both decide to emit a ping - and they still interfere with each other. The nasty part is that even if you can detect that an interference happened, (...) (19 years ago, 20-May-06, to lugnet.robotics)
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| | Re: Ultrasonic sensor interactions
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(...) A better alternative would be to develop protocols in which the NXT controllers use their communications to tell each other what they are about to do. If you can sent a message that says "I'm about to do an ultrasound 'ping' - so you'd better (...) (19 years ago, 20-May-06, to lugnet.robotics)
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| | Re: Ultrasonic sensor interactions
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(...) Very feasible... IF you could turn the US sensor off. As near as I can determine, the US sensor, when connected, is never off: it is always emitting a series of "pings" (you can actually hear a "click" from the sensor if you are really close). (...) (19 years ago, 20-May-06, to lugnet.robotics)
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| | BrickFest Bulletin: Mindstorms/Technic Contests and Events, Space Contests, Castle Contest and..
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(URL) Mindstorms/Technic Events BrickFest 2006 is fast approaching! This year, the Technic and Mindstorms Theme coordinators are pleased to announce 5 competitions. The competitions will be spread across the 3 days of BrickFest. The planned (...) (19 years ago, 20-May-06, to lugnet.events.brickfest, lugnet.events, lugnet.robotics, lugnet.robotics.events, lugnet.space, lugnet.castle, lugnet.general, lugnet.announce, lugnet.build.contests, FTX) !!
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| | Re: Ultrasonic sensor interactions
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Hi Tim, (...) it should be possible to use the ultrasonic sensor itself for that, there is a command to listen in on other sensors for that purpose. Jürgen (19 years ago, 20-May-06, to lugnet.robotics)
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| | Re: Ultrasonic sensor interactions
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(...) How feasible would it be to set up some sort of time-sharing communications over Bluetooth to allocate time slots when each of the robots in an area would be allowed to use their ultrasonic sensors? -Tim (19 years ago, 20-May-06, to lugnet.robotics)
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| | Re: Ultrasonic sensor interactions
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(...) In a word, multiple ultrasonic sensors can be a problem. This is a general problem and not specific to Lego ultrasonic sensors. Pulses emitted by "the other sensor" can arrive at just the wrong moment, creating a false range reading. Clever (...) (19 years ago, 19-May-06, to lugnet.robotics)
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| | Re: RCX Virus?
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(...) But (critically) not ALL of the stuff! (...) What I suggested was that your rechargable batteries are at the end of their lifespan. Buy a set of regular NON-RECHARGEABLE batteries and see if everything works OK then. If it does then toss out (...) (19 years ago, 19-May-06, to lugnet.robotics)
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