RoboLinx

Joe Hebert

I?m in the camp that believes that robotics is the next frontier. Has anyone dabbled in this technology? Better yet has anyone combined robotics with Netlinx? The closest I?ve gotten to robotics is playing around with the Lego Mindstorms that came out several years ago. They?re time consuming to build but fun to program. Whenever I get time (like that?s gonna happen) I?d love to back-engineer the program file transfer (it?s done via IR) and integrate it with Netlinx.

(If Pat Riley can copyright the word threepeat then I?m putting my dibs in on RoboLinx.)

B_Clements

Joe Hebert wrote:

(If Pat Riley can copyright the word threepeat then I?m putting my dibs in on RoboLinx.)

Sorry Joe, I put in my dibs first.

Chip Moody

I always thought it would be cool to take one of those robotic arms and try to find some kind of useful control system application for it... Like, use one of those and multiple CD-jukeboxes to manage a really HUGE CD library...

- Chip

Avophile

How about programming a pair of them to write code for you? Shades of Asimov...

annuello

Steppers

I've played around with stepper motors before (200 steps per rev), trying to make a CNC controlled milling machine. Constant current supplies are fantastic, since they give you amazing holding torque on a stepper motor.

Oatley Electronics (http://www.oatleyelectronics.com/kits/k142.html) make great driver circuits for steppers. They are designed to be driven off a parallel port, using 2 data lines (PulseDir). One line indicates the direction of rotation, the other is a clock pulse for each step. I wouldn't try and run such a board direct of NetLinx relays, due to latch/release delays.

A better approach would be to make a small micro circuit (PIC/Atmel) which sits on a 485 bus, waiting for commands from the NetLinx. "Rotate Left 37 steps". The micro would then generate the 2 control pulses for the Oatley circuit. Sitting on a 485 bus, you could have several motors in your system, only requiring one NetLinx port. It may be useful for the NetLinx to generate a heartbeat to ensure all the micros stay relativly in sync. When moving heavy robot arms around, collision = expensive!

My only issue with the Oatley circuit is that there is always one coil in the stepper energised. This is great for CNC of machinery, but you may want to be able to turn off the high current in some applications, once the motor has reached it's destination. E.g. Placement of telescope.

Do a Google search for "CNC stepper".

Yours,
Roger.

Thomas Hayes

What type of robotics are you interested in? I have a friend who just moved back from Dallas. He was a senoir robotics designer/programmer down there. He now owns a computer shop and still makes robots in his basement. He might have some info that he could pass on.