Introduction
Installing pbLua is a two step process. First, you must reflash the firmware on the NXT brick with the pbLua firmware. Second, you may have to install a driver so that your computer recognizes the pbLua enabled brick as a serial port.
Windows users have the usual series of screens to click though and .inf files to locate, while it “just works” for most Mac and Linux or BSD users.
To get started, download the most recent pbLua distribution and unpack it somewhere on your hard drive. It does not really matter where it goes, as long as you can remember the path later.
Reflashing the Firmware
There has been some discussion on Lugnet about the NXT Flash Lifetime. If you have any questions about how reflashing your NXT may affect its lifespan, read the thread and form your own opinion.
In the course of writing, testing, and debugging pbLua, I have reflashed my brick literally hundreds of times with no observable ill effects. You can always reflash the brick with the standard LEGO firmware at any time.
While there are standalone utilities out there for reflashing your brick, probably the easiest way is to use the LEGO NXT Programming Environment. Select Tools > Update Firmware and point at the directory where you put the nxt-lua.rfw file.
Put the NXT into reflash mode by pressing (and holding for at least 5 seconds) the reset button hidden in the Technic pin hole under the USB port. Although you can use a paperclip to press the button it’s much cooler to use a LEGO antenna.
When the reflash procedure is complete, reset the brick but don’t connect it to the USB port just yet.
Windows Install
If you’ve gone though any hardware installs before, you’ll be familiar with the procedure, but let’s review it here anyways. The procedure is known to work on Windows 2000 and Windows XP with minor differences between the screens. I do not have a Windows Vista machine to test on.
Please remember that each NXT you install, if you’re lucky enough to have multiple NXTs, will require a new driver install because the serial number will be unique. Similarly, plugging the same NXT into a different USB port will require a driver intall.
Make sure you’ve got the pbLua firmware running, and then plug it into the USB cable. Of course, you’ve got the other end of the cable plugged into your PC, right?
You’ll get a dialog something like this informing you that Windows thinks you have connected some new hardware. If not, there’s an issue with the USB cable, your USB port, or pbLua is not running on the NXT.
Shortly after it’s finished enumerating your NXT, the Hardware Wizard will start up and start asking you questions. Windows XP may also ask you to connect to the Internet to download a driver, but it’s in the directory that you unzipped the pbLua distribution to.
- Windows 2000 – Check “Install from a list or specific location” radio button and click “Next” to go to the next step.
- Windows XP – Check “No, not this time” radio button and click “Next” to go to the next step.
Now Windows wants some hints on where to look for the driver. To save some search time, you can tell Windows exactly where to look for the driver,
- Windows 2000 – “Don’t search. I will choose the driver to install” radio button and click “Next” to proceed to the next step.
- Windows XP – ???
Now you’ll have to fill in the path where Windows will find the pbLua.inf file that tells it how to talk to the NXT. Fill in or browse to the directory where you unzipped the pbLua distribution.
Windows now finds the driver and puts up some information to help you decide which driver to use. In this case, I have the original version from ATMEL as well as the one specific for pbLua. You’ll probably only see the latter one.
That’s it, you’re done! Open up the Device manager and you should see a new COM port ready for you to use. In this case, it’s COM3.
