 | | NXT to NXT communication? —Ross Crawford
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| | | Hi all you M[U|D]Ps I know most of the MDPs probably only have 1 NXT, but I'm hoping someone out there has 2, and has investigated NXT-NXT communication. Is it possible? How hard is it? I'm currently thinking Bluetooth, but is there any other way? (...) (18 years ago, 2-May-06, to lugnet.robotics)
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| | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | (...) Yep. I'm not at all sure about hardwiring two NXT's together - to be honest, I've not even thought about it, because BT connections are so easy and secure. Early on I investigated the BT option by sending simple numbers between two NXT's. But (...) (18 years ago, 2-May-06, to lugnet.robotics)
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| | | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | | (...) What about multiple NXTs? How well does Bluetooth handle message collisions? Does the NXT have anything built-in to handle them, or would I need to program some kind of re-try protocol? I assume it also has no built-in addressing protocol? (...) (18 years ago, 2-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | | (...) I can't speak for the NXT, but knowing that it has BT, and should be adhering to the specs, then the answer would be yes. The master-slave communication is coordinated via time slots within a piconet. This would avoid message collisions. In (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | | | (...) Ok after actually reading the other threads in this post, it looks like TLG decided to develop its own BT profile just for the NXT. The messaging mechanism described by Brian and Steve looks like it will allow direct slave-slave communication, (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | | Re: NXT to NXT communication? —John Hansen
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| | | | | | | | (...) I am not certain but I believe that the NXT does not allow direct slave-slave communication. An NXT can be both a master and a slave in a hierarchical array of NXTs (to the best of my knowledge) but two slave NXTs cannot directly communicate (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | | | Re: NXT to NXT communication? —Benton Jackson
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| | | | | | | | | (...) So, if any NXT can be both master and slave, could you hook 3 of them up in a triangle? A is master over B, B over C, and C over A? (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | | | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | | | | | | (...) Or even A master over B, B over A? ROSCO (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | | | | (...) OK...it looks like this messaging mechanism in (URL) is a little confusing. Steve cleared this up a bit in (URL) In the hierarchy he discussed, N0 has to go through N1 to talk to N2-4. This model can be extended to higher levels in a tree (...) (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —Steve Hassenplug
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| | | | | | (...) Dave, I don't know a whole lot about BT (beyond the little I've found out because of this project), but your assessment is correct. The protocol is implemented according to BT spec, so all communication is done through master-slave (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | | | (...) A little - the next question of course is: Can NXT1 be both slave (to NXT0) and master (to NXT2, NXT3, NXT4) at the same time? Or does that require sneaky protocol to switch between the 2? ROSCO (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | | Re: NXT to NXT communication? —Steve Hassenplug
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| | | | | | | | (...) Yes. NXT1 will be connected via connection 0 from NXT0 NXT1 will be connected via connection 1 to NXT2 NXT1 will be connected via connection 2 to NXT3 NXT1 will be connected via connection 3 to NXT4 NXT1 can send a message to connection 0,1,2, (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | | (...) Yes just kinda murky now! There are still good opportunities for a wireless network of NXT's! One could write a program on a single master and control as many lower level NXT's as you could bring together! Like one general commanding three (...) (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | Re: NXT to NXT communication? —John Barnes
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| | | | | (...) Hey Ross, With bluetooth built in, there is no real need for any other kind of brick to brick communication to be investigated. Bluetooth is a professional strength protocol with all the necessary networking features. Since it uses gobs of (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | Re: NXT to NXT communication? —Steve Hassenplug
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| | | | (...) Rosco, The NXT to NXT communication works very well, and is easy to use. Here's some video of an NXT controller for an NXT robot... (URL) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Joe Strout
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| | | | (...) they when you do that? Also, I noticed at one point you scooted the controller closer to the car. Was that because it had lost the signal? What is the effective range, anyway? I also wonder what happens when you have more than two NXT bricks (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | (...) Yep (at least that's one way to do it). I tried making a X-Y joystick, but the mechnical slop was more than I liked, so I've got one with two paddles and a thumbwheel (slightly different from Steve's) (...) Not too bad. The NXT motors are not (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Steve Hassenplug
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| | | | (...) The motors offer little resistance when used this way. However, there's something else which I think is kind of cool. If you look close, when I let go of the controller, the paddles return to the middle, and the car stops. Using just one block (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Rob Hendrix
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| | | | | (...) So you can use a motor port as a sensor input and/or use a motor as an input device (and vice-versa)? -Rob www.brickmodder.net (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | | Port types (Re: NXT to NXT communication?) —Steve Hassenplug
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| | | | | | (...) Not exactly. There was talk about that early on. You can not use the sensor port to drive a motor, and you can not use the motor port to read an analog (old style) sensor. The hardware specs may have changed, so I may not be 100% on this, but (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | | | Re: Port types (Re: NXT to NXT communication?) —John Barnes
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| | | | | | (...) Erm, can I clarify here; The digital sensor port which is part of the motor port is not the same as the digital port which is part of the main sensor ports. The two digital wires which are part of the motor port are input only, whereas the (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | (...) So they could potentially be programmed to provide force or shudder feedback? (...) Yes, but I'm interested to know: Are these multiple connections available via the LEGO retail software, or did you program your pair some other way? It's just (...) (18 years ago, 3-May-06, to lugnet.robotics)
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| | | | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | | (...) That's one possibility. (...) OK, that's a much better way of phrasing that :). The thing that's a little confusing (to me) is that means that if the NXT named "Ann" wants to communicate with one named "Ben", you can establish a BT connection (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | (...) Quite muddy! Why only three connections and what about specification adherence? Are they trying to limit its potential applications or were they just trying to get out a production-ready implementation? In other words are there plans for an (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | | | (...) John Barnes and others have been working on that. He has out a beta of a "Nxt Byte Code" (NBC) assembler, and he's dug into a *lot* of firmware and software details. See the following (& John's website) for more details. (URL) not as sure (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | | Re: NXT to NXT communication? —Kevin L. Clague
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| | | | | | | | (...) I a slight mis-statement. John Hansen is the NBC guy. Kevin (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | | | | (...) Thank you, Kevin - yes, I should have said John Hansen. My fault entirely, sorry about that John. (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | Re: NXT to NXT communication? —John Hansen
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| | | | | | (...) As Brian already mentioned I have produced a compiler for a text-based language (assembly) which is called Next Byte Codes (NBC) for a number of complicated reasons. Michael Barrett Anderson, who is the father of LASM and the RCX firmware, has (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Tim Byrne
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| | | | | (...) Steve, your remote is pretty cool. It’s a great idea if you have more than one NXT. I checked with my purchasing manager (my wife) and I don’t think my request for capital expenditure will be approved for more than one NXT this year. With that (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | Re: NXT to NXT communication? —Steve Hassenplug
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| | | | | | (...) Yes, that's a tough one... (...) I've played around with a few ideas using bluetooth. In addition to the NXT->NXT remote, I wrote a program for my Bluetooth enabled PDA using eVB. Jim Kelly actually has a screenshot in his blog (URL) under (...) (18 years ago, 4-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —Dick Swan
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| | | | | | | I haven't seen any discussion on the performance of the bluetooth messaging. I've measured PC to NXT round trip (send message and receive acknowledgement) as typically being 30 milliseconds. Has anyon else done these measurements and were your (...) (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | | | | | Re: NXT to NXT communication? —Brian Davis
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| | | | | | | | (...) I can't figure out a easy way for me to test PC-to-NXT timelag, but I tried some simple bench tests on NXT-to-NXT. This is just the old standard of two timed loops (10,0000 interations), one empty, and one with a single block (or two), and (...) (18 years ago, 5-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —David Hurley
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| | | | | | (...) <snipity> Jim (...) Did you say SDK?? Please elaborate on this... (18 years ago, 6-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | | (...) (URL) (18 years ago, 6-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —John Hansen
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| | | | | | (...) Hmmm... Speaking of SDK, based on a preliminary version of the Hardware SDK documentation the NXT is not capable of being both a master and a slave at the same time so a network of NXTs is limited to one master and three slaves and that's it. (...) (18 years ago, 11-May-06, to lugnet.robotics)
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| | | | | | | | Re: NXT to NXT communication? —Ross Crawford
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| | | | | | (...) Sounds like it's a firmware block though, so hopefully it can be overcome with "NxtOS" or whatever in future. ROSCO (18 years ago, 11-May-06, to lugnet.robotics)
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| | | | | | Re: NXT to NXT communication? —Kevin McClure
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| | | | (...) Very cool- the differential is very well designed, especially using only parts from the NXT. (...) Thats what I can't figure out how to do. I made a (modded) version of Brian Davis' DAZLR and using my grandfather's NXT have made a Remote (...) (18 years ago, 15-Jul-06, to lugnet.robotics)
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