OCaml Mindstorm is a library that enables to drive LEGOŽ mindstorm robots from OCaml through a Bluetooth or USB connection.

OCaml-mindstorm is a library that enables you to drive Lego mindsotrm NXT bricks from OCaml (the computer is the master and the brick is the slave).

Index of types
Index of exceptions
Index of values
Index of modules

How to connect the brick through bluetooth

You need to create a serial port connection using the instructions below for your platform. Then use Mindstorm.connect_bluetooth to create a handle for the brick.


First make sure your kernel has bluetooth support (this is likely) and that the bluez and bluez-gnome (or kdebluetooth) pakages are installed. You should see a bluetooth applet icon. Then do (the text after the $ sign is what you type, underneath is the answer):

	$ hcitool scan
	Scanning ...
        	00:16:53:03:A5:32     NXT

to discover the address of your brick. Then use Mindstorm.connect_bluetooth "00:16:53:03:A5:32" to establish the connection (of course, replace "00:16:53:03:A5:32" by your actual bluetooth address) -- the first time, the brick will ask you to enter a code and the bluetooth applet will pop up a box in which you need to copy the very same code (this is to forbid unwanted connections).


We follow here the instructions "Bluetooth Serial Port To NXT in OSX":

  1. Turn on the NXT brick and make sure bluetooth is on (you should see a bluetooth icon at the top left corner);
  2. Click the bluetooth icon in the menubar, select "Setup bluetooth device";
  3. When it asks for Select Device Type, choose "Any device";
  4. Select NXT (or whatever your brick is called but NXT is the factory setting so we'll use that from now on) from the list and click continue;
  5. The NXT will beep and ask for a passkey, choose 1234 (the default but you can choose anything you like) and press the orange button;
  6. Click continue in OSX, enter same passkey as above (1234 by default);
  7. The NXT will beep again, press orange button to use 1234 again;
  8. The mac will complain "There were no supported services found on your device"; don't worry about that and click continue and then click Quit;
  9. In OSX click the bluetooth icon, select "Open bluetooth preferences", you should see NXT (or whatever your brick is called) listed, select it, then click "Edit Serial Ports";
  10. It should show NXT-DevB-1 (replace NXT by the name of your brick), if not click add, use Port Name: NXT-DevB-1, Device Service: Dev B, Port type: RS-232. Click Apply.

You're done! You should now have a /dev/tty.NXT-DevB-1.

Now you can connect to the brick using Mindstorm.connect_bluetooth "/dev/tty.NXT-DevB-1". Beware that if you rename the brick with Mindstorm.set_brick_name, you will have to change the TTY device accordingly.


Without the fantom drivers installed

From windows, open the bluetooth control panel, create a new connection to the NXT brick, right click on your connection and select "details" to see which serial port is used, for example COM40. Then use Mindstorm.connect_bluetooth "COM40" to connect to the brick from your programs. ATM, you have to always start by establishing the connection by hand before you can use the brick. Patches are welcome so that is is enough to pass the bluetooth address to Mindstorm.connect_bluetooth and the library performs the connection.

Windows Vista uses different ports for outgoing and incoming connections (e.g. COM4 for outgoing connections and COM5 for incoming ones). With this library, you must use the outgoing port.

See also ruby-serialport/nxt on Windows with Cygwin.

With the fantom drivers installed

Once the fantom drivers are on your machine (which is the case if you installed the LEGOŽ NXTG software), the above method does not work anymore. It is then probably necessary to use these drivers through the Driver SDK. This will be investigated in a subsequent revision of this library.

How to connect the brick through USB


Create a lego group, add your user to it and create a file /etc/udev/rules.d/70-lego.rules containing

	# Lego NXT                                               -*-conf-*-
	BUS=="usb", SYSFS{idVendor}=="0694", GROUP="lego", MODE="0660"
	# Links for specific bricks (use udevinfo to find the serial)
	SYSFS{idVendor}=="0694", SYSFS{serial}=="xxxxxxxxxxxx", SYMLINK+="lego"

To be completed.




you need the LEGOŽ Mindstorms NXT software installed, as its USB drivers are used. ???