Programming the RCX with MPLab?

I’ve been wanting to program my RCX without the program it came with. I want to do this because the Robotics Invention System limits me greatly in programming. I don’t know how to program the IFI controllers, and I know they are most commonly programmed in C. So, I was wondering if there was a way to program the RCX with the MPLab or EasyC (preferably MPLab) so I could learn how to program more effectively while opening many new possibilities with the RCX. Is anyone able to help me?

Check out this Lego site and NQC. You wount be able to use MPlab to program an RCX. Your best option to learn C for the RC is to get a Vex kit or EDU-Bot.

I have the Mindstorms SDK downloaded, but never have been able to get it to communicate through my IR tower.

Try robolab. It has a graphical interface kind of similar to easyC, is specifically made for RCX/NXT use, and is MUCH more powerful than the language LEGO supplies. I’ve lost the link for where to get it, and will post it when I find it.

i dont think you can get the full version online but here is a demo


I’ve tried NQC and Mindscript(text version of RIS, and available in the SDK), but never found them to be very useful.

I’ve heard good things about LegOS, but I’ve never tried it.

If you’re really ambitious the Lego byte code for the RCX is fully documented in the SDK, so you could write your own compiler.:smiley:

I’m going to try the NQC. It looks like a nice program.

Please, keep telling me stuff. I would like to know what all is out there.

I’ve found NQC to be good enough for my usage. The general rule is that if you can’t do it in NQC (or Mindscript), you can’t do it with the official firmware.

Remember, every programmable brick Lego has made doesn’t work with native code; all programs are interpreted. This applies to the RCX, the Scout, the Spybotics controller, and the CyberMaster (somewhat rare). (I’m fairly certain it applies to the NXT, too, but I haven’t actually heard.)

My question is, why MPLAB? I could write a better IDE.

I was wondering if any of these are legal for teams to use for competitions. I hope so, that’d be pretty cool and a lot easier to use for my teams.

I would have to agree that NQC is most definitely the best mindstorms programming language for most people. While using the same firmware as the GUI Lego language uses limits NQC’s power, NQC allows the programmer to get at many features that are otherwise not accessable to RCX code.

If NQC is still not good enough you can always use:
-LegOS, is based of C/C++ and is probably the most compact language, as it runs directly on the RCX processor. However, it is also EXTREMELY difficult to setup/use/compile, from what I’ve heard.
-pbFORTH, great if you want to program in FORTH…
-LegJOS, a version of Java to run on the RCX. It really is object oriented, and has built in trig/higher math functions. Wish the same could be said for JavaME…
-There is also a way to program the RCX in Visually Basic. But that’s just sick.

I’ve been playing around with the basic program (just controlling motors, no sensors) and I like it pretty well. Thanks you guys!

You can also program the RCX using a language known as Interactive C. It is a C-like language that is actually a high-level front for a whole host of assembly level code blocks. It’s easy to learn, has decent documentation, and is (relatively) powerful despite its quirks.

I think as long as you don’t change the firmware its legal… but that would mean that NQC wouldn’t be legal i think dont quote me on that lol

If, as bear34rw stated, the only requirement is the original firmware, then NQC would be legal, since it uses the original firmware. The only issue is that last time I checked(2 years ago) they required the RIS or Robolab be used for the code handed in for judging.

Yeah, it would be completly legal. The only firmware I used was the original, although it was burried in the RIS folder. I still have to do some looking for it. It’s in there, you just have to look.

Edit: Found the firmware. Here’s the path.

C:\Program Files\LEGO MINDSTORMS\RIS 2.0\script\Firmware\firm0328.lgo

That’s on my computer, but it should be just about the same on most (unless you installed the RIS in a different area or you have something besides RIS 2.0).

Unfortunatly, only RIS and ROBOLAB are legal for FLL use.

I’ve never used Lego’s products, but a word of advice. If you’re the programmer for your team, and you want to practice developing code in an environment that parallels that of the actual FRC competition, get Vex.

The Vex controller/accessory’s were designed I believe to be identical to the FRC kit of parts, except smaller and cheaper. Thus the controller is very similar to the FRC robot controller.

If you do decide to buy vex, and use it with MPLAB, download this: . Some how that project is configured to work with Vex correctly, download it the first time, and save yourself heaps of trouble :slight_smile:

I checked this last year also, and it does require you use Robolab =/. I shall check again.