LEGO Engineering

Can I reprogram someone else’s RCX from mine?
One really great application of the reprogram command is to be able to load a program onto another RCX if the program is lost. If, for example, everyone is using the same program, the instructor could have an RCX that has a program to load up the standard program onto everyone else's RCX.In ...

Can I use rechargeable batteries in the RCX?
The short answer is yes. Alkalines are preferred, but you can use rechargeables. However, there are several disadvantages of which you should be aware. Disadvantages of Rechargeables: Most rechargeables, when fully charged, are only 1.2V instead of 1.5V. Thus, six batteries provide the RCX ...

How do I change the IR transmitter range level?
For RoboLab 2.5.4:With the serial IR transmitter there is a switch on the front panel.Select Short Range (smaller arrow).With the USB IR transmitter go to Start on your computer. For PCs select Settings: Control Panel: LEGO USB Tower: Select Medium or Short For Macintosh select Apple: Control Pan...

How do I plug my RCX transmitter (tower) into my computer?
There are two different types of transmitters, and depending on which one you have, it plugs into a different port on your computer.The USB IR transmitter is powered by USB and does not require a battery. It plugs into the USB port on your computer (the network symbol on the plug should face up, i...

How do I use the direct RCX communication commands?
Direct communication between RCXs requires that their IR ports be uncovered and facing each other. All of the commands sent between the RCXs are executed immediately.Here is a simple program to use to win a tug-of-war match. This program flips the direction of all of the outputs of the other RCX (ca...

How do I use the Interrogate RCX function?
The interrogate RCX command is a very useful way to see what is going on with your program while it is running. Interrogate RCX opens up continuous communication between your computer and the RCX. To open interrogate RCX go to Projects -> Interrogate RCX.Here is a program that se...

How do I use the mail command on the RCX?
The RCX is always ready to receive mail which means that all you need to do to send a mail value is to wire in the send mail icon which can be found under RCX communications. The code below makes the RCX send a mail value of 85:Mail values can only be 0-255, and only one number can be held in ...

How does my RCX connect to my transmitter?
The RCX communicates to the tower through infrared (IR) technology. There are no wires used to connect the RCX to the tower. However, there must be an uninterrupted field of vision to the "eye" located on the front of the RCX unit. You can tell when the RCX is communicating when you ...

How is direct RCX communication different than the remote program commands?
The direct RCX communication command sends commands that are executed immediately. The reprogram commands that are sent are only executed after the run button has been pressed.Here is a good example of using both functions to send and execute a program on another RCX:AGses

I have purchased earlier LEGO® Control products. Can I use any of these with the Mindstorms® sets?
Any 9 volt motor, lamp or sensor purchased earlier will also work with the RCX and the RoboLab system. Electric components from LEGO TC Logo (4.5 volt) will not work with the new system.

I seem to lose firmware all the time - what's going on?
Cause: Low battery level Solution: Replace batteries.Cause: Smaller batteries - Sometimes batteries (often cheaper brands) are too small and they can fall out from in-between the terminals when the RCX is moved.Solution: Replace with new, higher quality batteries. Load all the batteries ...

I've plugged in my IR tower, but RoboLab doesn't sense it. What can I do?
First, go to Administrator and see if USB #1 is listed as one of the COM ports. If it is listed, select it.If USB #1 is not listed, this means that the IR tower driver was not installed properly. The solution is to go to the Tower folder, which is within the RoboLab folder on your hard drive, and ru...

Is it possible to plug a motor into the input ports?
Yes, on the RCX. The motors can be treated as sensors.The NXT motors can be used as sensors while plugged into an output port. By clicking on the NXT comands icon, in the new Robolab software, a selection of "Value of" icons will be avaible for output ports A, B, and CBy connecting a motor ...

Is it possible to use other sensors with the RCX?
There are a lot of other sensors that can be used in conjunction with the RCX, all of which can be found in the sensor adaptors list. For example, here is a program that logs the pH over a time span of 10 seconds. All of these sensors are treated exactly the same as the standard RCX sensors and ar...

Is it possible to use the same VI to load programs on two different RCXs?
The best way to use one load one VI onto multiple RCXs is to use multiple IR towers. Wire in the advanced RCX start signs and make sure to wire in the correct port values: AGses

Is there a way to change port values and settings through the interrogate RCX command?
Yes. It is possible to change the way that ports are configured, as well as motor speed and direction, through 'interrogate RCX'.By running 'interrogate RCX', found under the administrator tab, port values can be changed. Below, port three has been changed to a raw switch. Below the pict...

My IR tower and RCX are not communicating. What should I do?
Here is a list of things to try if you are having problems downloading to your RCX. Try to block the ambient light that might disrupt the IR transmitter beam: close the window coverings, turn off all the overhead lights, and/or cover the RCX and transmitter tower with a dark cloth or a box. ...

My RCX car spins in place - Why won't it move?
If the wheels are turning in opposite directions, the direction of a motor can be changed by rotating the wire 180 degrees and plugging it back in. Bad: Car spins clockwise Good: Car goes forw...

My RCX will not turn on.
Cause: The batteries are dead.Solution: The batteries should be replaced one at a time so that the Firmware software on the RCX is not lost. However, if lost, the firmware can be downloaded again, so it is not a terrible problem if loss of firmware occurs during battery replacement.C...

The computer says no response from RCX tower.
Cause: Tower is not plugged in.Solution: Plug tower into computer.Cause: Tower was moved during download.Solution: Make sure tower does not move at all during download.Cause: RCX lost power and has to download Firmware.Solution: ROBOLAB will ask if you want to dow...