Look a Like Lego® RCX project

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

I''m busy with the hardware for a Look a like RCX from Lego. The rcx from lego has 3 motor outputs and 3 sensor inputs. The programs are loaded with infrared and the hole system works on 9Volt.

The version i planed to make is a 6 motor output all speeds regulated, minimal 6 sensor inputs and to load code into it with IR but also the possibelitty to link a RF link to the module.

Also we try to make the sensor inputs compatible with the Lego® sensors.
These sensors have a special way for power and readout on 2 wire interface. This is a tricky problem where i can't find a solution for.
Somebody else did the following using bascom: LINK '

Another big sensor page: LINK

I'm wondering if there are people here that will help to setup this robot controller project with many functions as an sort of open source project.
I'm self the owner of a dutch Lego Robotics club, and that was the idea that i wanted to make such controller.

Greets Daniel Wittenaar
Brickbash Robotics Cool

[EDIT] Forgot to give a link to a very big sensor page Wink

satz · Joined: 26 Apr 2004 Posts: 22

Hi,

I'm interested, if you're using the AVR controller
and Bascom-AVR.

Please give more details.

Rgds,
Satz

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Ah finally somebody who wan't to join.. Very Happy

Well i'm collecting data now and and i'm in a testing fase to try bits of code to get little pieces to work.. About some week of 3 i will try to release some code that people can try..

My best part is hardware.. But some hardware could only be developt when i know for shure if it works with the software.. Wink

So still busy with experimenting..

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Somebody knows a way to generate 6 PWM channels without using the internal occilators?(OC1)

Maybe with a liberary with ASM code.. So i can call it like PWM1=122 To get it working Wink

It should be the best way to make a $lib for this. So the code can be hold small..

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Well found this solution on the web: Lego sensor readout

and supplied me with some code to readout the special 2 wire sensors from Lego..

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Allright with some brainstorming i came up a way to generate 6 'pwm' channels in software mode..

Need a sepperated AVR just for PWm because otherwise the program's around it take to much time to generate a nice pwm pulse..

Only now i'm trying to make some way to set the value's without interupting the PWM to much.. (With motors attached you can't notish but with led's you see it blink a bit when you change a value..

So here the bare code without the Value interface where i'm still working on:

This is based on a 90s2313 on 4Mhz (stk 200 board)

Ro-Bot-X · Posted: Wed Nov 16, 2005 4:12 pm Post subject: AVR based Lego controller

Hi, My name is Gabriel Petrut, I am from Romania, presently in USA.

I am verry interested in building such a controller. I have built smaller controllers, using a Nemesis controller (PIC 16F88), capable of driving 2 motors and 2 Lego sensors and has 2 more 3 pin I/O, for distance sensors, servos or, using an adapter, 2 more Lego sensors. Link

I am new to AVR, so I will try to follow your sample codes and build a test controller on a breadboard to see how it works. After all is tested, I will make a PCB for it and place it in Lego brics. I also am interested if anyone has made a graphical programing language like Lego software or Robolab, to be used with AVR. It is easier to teach kids to use this to program their robots...

I know how to use the Lego sensors. I also know how to build the motor driver using SN754410 and built in hwpwm, but it has only 3. So, your solution for 6 motors is of real interest to me. I also am interested to see how is IR serial link going to be made to use the Lego IR Tower. Also, if possible, I want to be able to use this IR message system as a IR proximity detector, without having to use Light sensors to detect the IR bounce. (I can do that with Nemesis verry well right now, but not the IR programming.)

Thank you for sharing,

Gabriel[/url][/u]

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Hmmm i typed a hole story before this post.. but because some cookie problems i lost the whole bunch of text..

Everything i would have told will become clear in a few weeks..

Have a lot of stuff running here so have to pull everything together till it is a whole controller..

vinodkumar · Joined: 18 Oct 2005 Posts: 7 Location: Jabalpur

Our Institute has developed a robotics board based on AT89S52 . the board has capability to control two geared motors, four reflective IR sensors, 8 channel 8 bit ADC and two stepper motor controller as add on board. with a 16*2LCD and 16 digital I/O lines.

we are using bascomdemo version to control two motors in conjunction with the four reflective IR sensors to make all sorts of robots, wall hugging, obstacle avoiding,. we are doing studies on maze solving capabilities with very good results.

DJD XTREEM · Joined: 24 Jun 2004 Posts: 190 Location: 127.0.0.1

Hmnm really nice.

I only don't know why are you using a 89S series processor?

I like the newer generation of avr much better for outstanding perfomance and fast flashable..

Not sure how that is implement on the 89s series..

But maze solving is a nice subject to build controllers for..
My board will be easy to cofigure in most applications.
But that will take some more time to develope.. Wink

mick · Joined: 06 Feb 2005 Posts: 12

March 08, 2005

Atmel’s New Single-Cycle 8051 Core Provides Big Performance Boost and Low Power

Single Cycle Core-AT89LP Family

The Atmel AT89LP family is a low-power, high-performance 8-bit microcontroller with an Enhanced 8051 CPU.
In the classic 8051 core, every fetch requires at least 6 clock cycles. The LP family is built around an
enhanced core that can fetch a single byte from memory every clock cycle. In the 89LP family CPU,
instructions need only 1 to 4 clock cycles providing 6 to 12 times more throughput than the standard 8051.

The enhanced CPU core is capable of 20 MIPS

These devices can operate down to a low voltage of 2.0V.

The AT89LP family devices consist of In-Application Programming Flash, On-Chip DataFlash®,
PWM, 10-bit ADC, Analog Comparator, Watch Dog, SPI, which reduces System cost and enables
faster time to market.

more here

http://www.atmel.com/products/8051/at89lp.asp Wink