[Gasification] Lego

[Mark Ludlow]

Mike:

I've bought lots of PLCs, stepper motor driving modules, PID controllers and
sensors and transducers of all kinds-most of it brand-new, on eBay. Servos
are fun and work well for robots and the like, but analog processes
typically are controlled best with a feedback loop that measures the
response of the process to a change in the control signal. Most of this
industrial stuff interfaces very easily and all of it is rugged and noise
immune. I recommend the Micro3 series of PLCs (Omron) and Watlow analog PID
controllers. The PID controllers have thermocouple inputs as well as
millivolt, 4-20ma, etc., so there's not much challenge to interface wiring.
Plus, they typically have several digital outputs for alarms or general
control, and, often, retransmit outputs for process or control values,
useful with something like a USB connected A->D device that feeds your data
directly into an Excel spreadsheet. And if you're cunning (and addicted to
eBay!), $100 will get you all you are likely to need, (with the exception of
the USB device).

Processes with relatively large time constants (i.e.., a gasifier) can often
employ "digital" rather that continuous (analog) devices at great savings in
cost and increases in reliability. For instance, a PLC can be programmed to
pulse a solenoid valve that controls an air bleed.

Another plus is that there's virtually no programming hill to climb.

Good Luck!

Mark

-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Michael Redler
Sent: Sunday, May 21, 2006 8:36 AM
To: gasification at listserv.repp.org
Subject: Re: [Gasification] Lego


I'm also a big fan of Lego and without trying to take away from your idea,
I've been trying to figure out what to do with the 8 computers I have in my
basement.
   
  I wish I could find a forum which discuss resurrecting old computers and
converting them into data collection machines and control systems.
   
  Mike 

drew <drew at artforging.com> wrote:
  Those of you who are interested in automation of gassifiers and governers
for engines should check out the new LEGO, mindstorms invention system. I
have been following it's develpment closely and think for prototype
equiptment automation and data loging there is not equal, especialy in terms
of cost and simplicity. They do not have a temperature sensor yet, but they
are making the software open source, and there are already other
manufacturers looking to make other aftermarket sensors for them. The motors
are true servo motors and I have been assured by a friend much more
e-hardware competetent to me that getting this controller to run larger
motors will not be too difficult. 
Cost- 350 bucks for controler and includes 3 servomotors, a touch sensor, a
light/color sensor (make a nice tachometer) a ranging utrasonic sensor, and
a sound sensor.

http://mindstorms.lego.com/overview/

already one after market developer is working on other sensors and the
robotics comunity is buzzing about the open source software, this other
developer plans to release a duplexer that will double the number of ports
on the controler

Copied from the website


The NXT is the brain of a MINDSTORMSR robot. It's an intelligent,
computer-controlled LEGOR brick that lets a MINDSTORMS robot come alive and
perform different operations.

*Motor ports*
The NXT has three output ports for attaching motors - Ports A, B and C

*Sensor ports *
The NXT has four input ports for attaching sensors - Ports 1, 2, 3 and 4.

*USB port
* Connect a USB cable to the USB port and download programs from your
computer to the NXT (or upload data from the robot to your computer). 
You can also use the wireless Bluetooth connection for uploading and
downloading.

*Loudspeaker
* Make a program with real sounds and listen to them when you run the
program

*NXT Buttons*
Orange button : On/Enter /Run
Light grey arrows: Used for moving left and right in the NXT menu Dark grey
button: Clear/Go back

*NXT Display*
Your NXT comes with many display features - see the MINDSTORMS NXT Users
Guide that comes with your NXT kit for specific information on display icons
and options

*Technical specifications*

* 32-bit ARM7 microcontroller
* 256 Kbytes FLASH, 64 Kbytes RAM
* 8-bit AVR microcontroller
* 4 Kbytes FLASH, 512 Byte RAM
* Bluetooth wireless communication (Bluetooth Class II V2.0 compliant)
* USB full speed port (12 Mbit/s)
* 4 input ports, 6-wire cable digital platform (One port includes a IEC
61158 Type 4/EN 50 170 compliant expansion port for future use)
* 3 output ports, 6-wire cable digital platform
* 100 x 64 pixel LCD graphical display
* Loudspeaker - 8 kHz sound quality. Sound channel with 8-bit resolution and
2-16 KHz sample rate.
* Power source: 6 AA batteries

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