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 Robotics / 2391
  RCX Limitations, griping, etc. :)
 
Only 3 input ports... only 3 output ports... no expandability... The only redeeming thing for it from a programmer's point of view is LegOS. ARGH!!! Okay... I'll try to calm down. Lessee...what are the alternatives? Well, there's the MIT (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  RE: RCX Limitations, griping, etc. :)
 
Don't forget the venerable 6811-based, sensor-rich, Rug Warrior Pro. If you like LEGO RCX, you'll like this one alot. A bit expensive though -- I paid about US$550. But it includes the robot, sensors, motors, Interactive C development environment, (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Re: RCX Limitations, griping, etc. :)
 
(...) Ahhhh....but alas my friend, that is where the challenge lies. Hey...the Apollo missions had less to work with. :) (...) Well...the RCX *is* the commercialized version of the MIT work. (...) Yep, I agree. (...) ...and just a tad too large to (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Working around the 3 output limitation
 
Someone mentioned a few days back that for a mobile robot you need to use 2 outputs for the motors. I reckon you can get around that on the proviso that you *don't want to stop* one of the motors... Make your chassis like a car, with rack-and-pinion (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) There are other ways to do this as well. The most advanced is to think of each motor output as being two outputs (forward and reverse). If you built devices so that they work with the motor going in only one direction (possible for a claw, (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) Another option is to use "half motors" -- ie, if you are using 360 degree 4-wheel steering and driving all four wheels, those drive wheels never need to go in reverse. You can use a differential and two ratchets to separate the forward motion (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
This is a little ramble on the subject. The ideas in the later posts of this thread are in my opinion what Lego **is**. It is innovation in the face of "limited" options. It is creativity and problem solving. When I bought my Mindstorms it said (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
Linc Smith writes: > The ideas in the later posts of this thread are in my opinion what Lego > **is**. It is innovation in the face of "limited" options. Any device will have limitations. The beauty of Mindstorms is that anything I build with mine, (...) (25 years ago, 6-Jan-99, to lugnet.robotics)
 
  So why build robots out of LEGO in the first place?
 
I have made the following personal observations about LEGO, and why it is my medium of choice for robot building. LEGO is very easy to assemble. You can figure out what you want beforehand, without really needing to worry too much about (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
Mark Tarrabain wrote (...) my (...) <snip... a number of good reasons with which I agree (except for the Popsicle sticks and rubber-bands... good-god Man! have you gone _mad_? :) (1) (...) the (...) actually (...) lack (...) with in (...) Ahhh! (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) I've got an working design that SEEMS to get around the problem of cumulative error. I use a gear plate that sits atop a regular gear. Since it's held in place by gravity, when it hits the limit of travel it simply slips. This allows me to (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
snip (...) snip You may also want to check this page for a rotating and lifting arm that is controlled by one motor only: (URL) 'Asking directions' from menu Eric Brok Visit LEGO ON MY MIND: (URL) Control section: (URL) section: (URL) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  RE: So why build robots out of LEGO in the first place?
 
Just a question, Where an inmature lego follower can find the Lego Purity Commandments? I am a kind of new in this _religion_, but I hardly try not to be a sinner. Thanks for the Light in the Darkness, David (...) -- Did you check the web site (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
Dear David my sinful son, The first step on the path to redemption to for you to tithe ten percent of your LEGOs to *me* every month! - - - Nick - - - (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
Reverent Legoists, For a mere five percent of your legos I will send you special cans of Lego(tm) air. I bring this down once a week from the top of Mount Lego(tm). This air can be used in all of your pneumatic devices. Also, for those holiest of (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
(...) I've just got one thing to say to you - MEGA BLOX! Yes, it was meant to be funny, don't flame me I've had more than a thousand million of them already... Yes, that was another one - laugh, damn it, or I'll tell another! (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  RE: So why build robots out of LEGO in the first place?
 
Let me propose a set of commandments for "Lego Good Style Construction" (blames and riots are allowed): 1.- "You should love your Lego's in the same way you Love your life" 2.- "Any damage to a Lego part is completely forbidden. The home-brew (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Ethernet for RCX?
 
Hi, Has anyone put any thought into getting the RCX to output to an Ethernet interface? Of course, what I'm really interested in is an entire TCP/IP stack- Ethernet hardware, RCX Ethernet driver, IP stack, TCP stack, and a BSD sockets API, but I (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Ethernet for RCX?
 
(...) When I saw mention of Lisp, I began to suspect I was in the comany of lunatics. This definitely confirms it. :-) Cheers, Ben. -- (URL) grandfather once told me that there are two kinds of people: those who work and those who take the credit. (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Ethernet for RCX?
 
(...) Let me guess... you want to run Apache on the RCX and serve digital camera images, so that people can drive your bot around from the web? :) Here's a piece of Zen for you: Q: How do you fit a mountain in a teacup? A: Dig for the diamond, then (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
David Colomer wrote in message <000f01be3a59$0bdebe...oup.cl>... (...) This is a good set of "good Style" ideas, but a Lego Purists would only agree with one of your statements... (...) The rest, well.... (...) We like the idea of damaging (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  RE: So why build robots out of LEGO in the first place?
 
This is almost Ok with me! If you allow to mutillate Lego parts, this will be against the 1st statement. I think that a MB brick, multillated in order to build (or help to build) a Lego part will be released from the original sin of MB and converted (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
Geeze... all this because I mentioned popsicle sticks and rubber bands??? Actually, I've never had occasion to use a popsicle stick in any model, I was just trying to make a point. I have used rubber bands, though... and I have used pens or pencils (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Ethernet for RCX?
 
(...) I don't know how you would get to it without hacking hardware and putting an Ethernet controller in external address space, and then writing the code for it. One problem: Ethernet needs a far amount of buffer space to keep up with packets and (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  RE: So why build robots out of LEGO in the first place?
 
"Excusatio non petita, acusatio manifesta" (A not requested 'sorry' is like a true 'my fault'). We are not speaking about use pecils (in a Lego structure) or cartridge (in another Lego structure). This is much more religious stuff than that. Join (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: So why build robots out of LEGO in the first place?
 
Oh no! i have commited a sin! I created a lego light! -Chris (...) religion (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: Ethernet for RCX?
 
(...) Have a look at this site and I think you are on your way! It's an embedded 10BaseT Ethernet controller using a PIC16C74. (URL) Ljungstrand; PLAY Research Group, Viktoria Institute (URL) Mobile: +46-(0)708-302251 Fax: +46-(0)31-7735530 ICQ: (...) (25 years ago, 8-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
Stuart, what are the ZNAP kits? Have you got a kit # for it? Thanks... <ICS> -- Did you check the web site first?: (URL) (25 years ago, 14-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) Brett, I don't follow this... What is a gear plate? Do you have any pics available? <ICS> -- Did you check the web site first?: (URL) (25 years ago, 14-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) I know, and I'm sorry I can't seem to explain it with words. (...) Probably not the "official" term for it. It's a 1x4 plate with teeth on one side used to convert rotational motion (from a gear) to linear motion. I use it to move my shifting (...) (25 years ago, 15-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) ZNAP kits with motors are: #3571, #3552, #3591 approx UK prices (1UKP=1.6USD) 14 17 lots! For robotics purposes the other parts in these kits are a complete waste of time - they're not even much like normal Lego - but may well be cheaper than (...) (25 years ago, 15-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) I think this is right. After all, we could all start with an asortmaent of bits of metal and plastic and a hobby engineering shop, and build arbitrary robot designs; and *probably*, it wouldn't cost a huge amount more than the mindstorms kit (...) (25 years ago, 16-Jan-99, to lugnet.robotics)
 
  Re: Ethernet for RCX?
 
(...) I really don't think you'll do this in 32k and still have space for application layer code (mind you, if I'm wrong, I'll be the first to cheer...) (...) This looks a more promising start. Use a *very* simplified protocol over the IR link, have (...) (25 years ago, 17-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
snip (...) Actually there is a working LEGO compass, put probably not large and reliable enough to be read by a sensor. Eric Brok (25 years ago, 18-Jan-99, to lugnet.robotics)
 
  navigation with compass
 
(...) Light sensor with a magnifier? :-) I tried using the differential gear to "remember" the initial heading of my robot, and painfully discovered that the result would drift off after many turns. Now I think compass is the way to go. (I wonder (...) (25 years ago, 22-Jan-99, to lugnet.robotics)
 
  (canceled)
 
 
  (canceled)
 
 
  (canceled)
 
 
  Re: navigation with compass
 
What is a source for your floating compass? - - - Nick - - - Hao-yang Wang wrote: <snip> (...) -- Did you check the web site first?: (URL) (25 years ago, 22-Jan-99, to lugnet.robotics)
 
  RE: navigation with compass
 
Here's some info on a compass sensor from Dinsmore Instrument Company for about 12 bucks. FYI (URL) >>Having said that at some stage I'm going to hook a compass up to my RCX, (...) -- Did you check the web site first?: (URL) (25 years ago, 23-Jan-99, to lugnet.robotics)
 
  Re: Working around the 3 output limitation
 
(...) The one with two studs in the middle, and two holes at the ends? and you then have one of the half-bushings with teething (1) thaty it rests on? I would say that those teehings are too deep too slip comfortably, but I haven't tried it out. (1) (...) (25 years ago, 23-Jan-99, to lugnet.robotics)
 
  RE: navigation with compass
 
(...) -- Did you check the web site first?: (URL) (25 years ago, 24-Jan-99, to lugnet.robotics)
 
  Re: navigation with compass
 
(...) Richard (25 years ago, 24-Jan-99, to lugnet.robotics)
 
  Re: navigation with compass
 
Sorry for this late follow-up to this old thread. Real Life has kept me away from Lego for the whole week, and finally I am back. Searching for "compass" in the LUGNET news archive turns up 28 entries, so this topic has been discussed long ago, and (...) (25 years ago, 2-Feb-99, to lugnet.robotics)

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