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Lego Mindstorm and the Propeller - Anybody looked at the combo — Parallax Forums

Lego Mindstorm and the Propeller - Anybody looked at the combo

EricGarlicEricGarlic Posts: 41
edited 2012-04-27 06:33 in Propeller 1
Hello,

My son has a Lego Mindstorm (NXT). Anybody tried hooking it up (communicate) with a propeller?

I believe NXT can communicate via I2C. But before I dive into the project I thought I would trawl for any top tips and examples (I hope I'm not being lazy, I think they call it knowledge sharing)

Cheers
Eric

Comments

  • InSilicoInSilico Posts: 52
    edited 2009-02-14 13:39
    It does have an interface for third party applications. They also have schematics and documentation on the details of the system:

    http://mindstorms.lego.com/Overview/NXTreme.aspx
    http://en.wikipedia.org/wiki/Lego_Mindstorms_NXT

    At the end of the wikipedia page there's a pinout of the connectors used, and yes you're right, it does have I2C (and RS485)

    Hope this helps!
  • TreeLabTreeLab Posts: 138
    edited 2009-02-14 17:29
    Some friends have told me that the program capacity of the main brick is very limited. Is this true? If so, replacing the main brick with a prop would be an interesting project for me. The hardware dev kit from LEGO is very complete, but I have not seen the specs on the motors yet.
    Cheers!
    Paul Rowntree
  • EricGarlicEricGarlic Posts: 41
    edited 2009-02-14 18:45
    InSilico - Cheers. Lots to read. Eric
  • MightorMightor Posts: 338
    edited 2009-02-14 20:21
    TreeLab said...
    Some friends have told me that the program capacity of the main brick is very limited. Is this true? If so, replacing the main brick with a prop would be an interesting project for me. The hardware dev kit from LEGO is very complete, but I have not seen the specs on the motors yet.
    Cheers!
    Paul Rowntree
    The programming capacity is anything but limited. I use the NXT brick with RobotC which doesn't have a lot of the limitations that the standard firmware. With the 4 I2C connectors you can add a lot of additional hardware. It is fairly trivial to connect a few bricks together with either BT or RS485.

    Regards,
    Xander

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    | To know recursion, you must first know recursion.
    | Current projects and ramblings: I'd Rather Be Building Robots
  • InSilicoInSilico Posts: 52
    edited 2009-02-15 02:25
    with I2C you can add as many I2C peripherals on the same bus (e.g. daisy chaining). You're only limited to the bus capacitance (cannot go over 400pF IIRC). So even if you only have one port left, you can put in maybe about a dozen on the same bus.

    the real issue with putting that many on one bus·segment though,·is slave address conflicts.

    Post Edited (InSilico) : 2/15/2009 2:35:02 AM GMT
  • ElectricAyeElectricAye Posts: 4,561
    edited 2009-05-17 06:09
    Hi,
    I was just wondering if anyone made progress with this idea. My son is a little young to deal with a laptop but I now have a cursor and VGA controller for my Prop, so I thought maybe, just maybe, it might be possible to make a simple Prop-based system that would allow him to click and play.

    thanks,
    Mark
  • TimmooreTimmoore Posts: 1,031
    edited 2009-05-17 06:18
    I have a prop board with a number of sensors on it acting as a I2C slave. I haven't tried it with a mindstorms Nxt but the I2C master implementation that I am working with has the same limitations as the Nxt (it was designed to work with Nxt sensors).
    I modified Hippy's I2C slave software to work against it - remove some functionality that the master can't handle and fixed a couple of bugs.
    You can also attach some I2C sensors directly to the Nxt - I expect for example the SRF02 sonar to work.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-03-22 01:27
    Well, I guess it's been about a year since anybody brought this up.... So has anyone here made any progress getting a Prop to talk to LEGO Mindstorm devices?

    smurf.gif
  • whickerwhicker Posts: 749
    edited 2010-03-22 01:50
    Not mindstorm NXT, but I have in the past gotten the IR communication from the new Power Functions receivers to work, of which the protocol is also open-source.

    I was lazy and used spin-- it's just barely fast enough when using one of the first 9 pins... however I had thoughts about using the counters for the carrier frequency.
  • Cats92Cats92 Posts: 149
    edited 2012-04-27 02:17
    Hello,

    Nothing new for getting a Propeller to talk to LEGO Mindstorm devices?

    Trying to learn robotic to kids I think it will be very usefull to have a shield and program .

    It will help to make Propeller use attractive for this kids. They like building with Lego blocks.


    I found something for the Arduino (at Openelectrons.com) but nothing for the Propeller.

    Jean Paul
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-04-27 05:57
    Cats92 wrote: »
    ...

    Nothing new for getting a Propeller to talk to LEGO Mindstorm devices?....

    I found something for the Arduino (at Openelectrons.com) but nothing for the Propeller....

    I've been pondering the same thing for a long time, but have not actually tried to make any progress yet.

    There's a device that allows the Mindstorms to communicate via Xbee, so that could provide a bridge of sorts or at least some clues about how to make an interface:

    http://robomatter.com/Shop-By-Robot/NXT-Robots/Hardware/NXTBee-Sensor

    I came across the following link that might be helpful if you are so inclined to make your own sensors:

    http://www.extremenxt.com/lego.htm

    There are also some hardware schematics, etc. at the bottom of the following page:
    http://www.legoengineering.com/knowledgemanager/questions/154/Where+can+I+find+technical+specifications+for+the+NXT+brick%3F

    Obviously, if the Arduino can interface with Mindstorms, then the Propeller can do it, too, but I suppose it's just a matter of working out what sort of handshaking must take place.
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-04-27 06:33
    You can add me to the list of those that have been thinking about this.

    I haven't tried this yet but it is on my list of things to do.

    As I read this, the idea is to replace the LEGO brick with a propeller based board (and connectors) and hook it up to the NXT (or RCX) sensors and motors?

    You would think it could be done.

    Maybe a QuickStart with a protoboard and a number of the RJ-xx (they use something non-standard) connectors. The hardware investment is certainly less than buying a brick. Someplace, I had found some pretty detailed infor on the interfaces and if we can get to the Arduino stuff, that should be re-creatable on the Prop.

    12blocks would be a good coding environment. It's drag and drop and let's you graduate to SPIN. I haven't looked at it but there is some sort of support in 12Blocks for the Mindstorm - it could just be a skeleton for future development.

    Maybe it's time to reorganize my To-Do list (again).
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