Fun with LEGO Mindstorms Programming

rhempel wrote to us about an interesting LEGO Mindstorms programming tool he's created called pbForth. Click below to learn more about it - but let's talk about Mindstorms programming in general. What else is everyone using? What's the coolest thing you've done with them?

I've developed pbForth, a port of a rather archaic programming language, for the LEGO Mindstorms brick. The cool thing about it is that with a dumb terminal emulator that does ASCII uploads and can handle XMODEM (checksum) transfers, you can compile applications right on the brick! Yes, on the brick! When you are done, you blast S records back to your PC using XMODEM and then you can reload the app anytime using one of the standard firmware uploaders.

Check out pbForth for LEGO Mindstorms

pbForth got a whole chapter in the O'Reilly book, and it is getting more and more momentum as replacement firmware that busts the 32 variable barrier, and allows total cross-platform development without screwing around with building ecgs.

OK, I'm biased - I wrote it - but I think it's cool. Maybe some of you LEGO gearheads out there would like to try programming in something other than the native tongue. Learning Forth can make you a better C programmer. No, I'm not a Forth evangelist - I write embedded systems in C all day long.

Comments

WebCam mount, NQC, legOS

[Fastolfe]

Firstly, legOS is a really cool project. They've totally re-written the firmware for the RCX and built a fully pre-emptive multitasking environment running programs you can write in C or C++ and compile with a gcc cross-compiler. Very cool stuff, though the networking support (IR) doesn't seem very usable just yet.

NQC uses the standard firmware I believe, and is a bit more solidified. You write programs in a pseudo-C language and compile/upload it using the NQC utility. It also has some good IR message passing abilities.

Information about both of these can be found at LUGNET in the robotics section.

I experimented with LegOS a while back but ended up using NQC and a bunch of server-side Perl to build myself a telerobotic camera mount for my webcam.

There are definitely tools available out there for some extremely flexible Mindstorms programming.

PRC

[miahrogers]

I was in the Penninsula Robotics Competition here in south eastern Virginia. We(my school's team) had to build a robot that would drive around a rectangular course and collect small white wiffle balls.

Programming for the Mindstorms robots isn't very hard. However there are many other problems with them.

For one you are only allowed to have three engines on a given mindstorms robot. I guess i should more accuratly say that you are only given 3 power terminals to plug your engines into, you may plug in more than three engines, but then two of them must go in the same direction.

Another problem with the mindstorms robots is that they don't allow much room for a "smart" robot, as you are only given 3 sensors (like the engines above you can plug in more than three sensors but then two of them must respond to the same stimulus).

Also the strength of legos in general is much worse when you try to put legos and a moving vehicle into one. Your building style will have to be entirely reformed if you plan on keeping your mindstorm alive for more than 10 minutes. The technic legos help with this a little, because they are longer and contain those neat axle shafts which we used liberally. But overall if you decide to change anything on the robot it will have to be entirely rebuilt for strengh/durability reasons.

The last major problem with mindstorms robots is that they cost way too much. For a kit including three engines, a bunch of legos, and one cpu unit(basically the bare minimum you can get by on if you want a robot that moves), it was > 500$.