Saturday, October 9, 2010

Other robotics fronts

iRobot Create

A couple weeks ago, iRobot visited the local high school robotics club, where I have been assisting, and donated 6 iRobots create with some additional components, included a command module.

Although I own several *ahem* - a lot of iRobot consumer products, the Create with a command module provides me my robotics fix while I fix my other projects.

So far I have just modified and cleaned up the example programs (which are poorly coded).  Currently it just drives straight until it hits something, and then turns.  Next week I will be teaching the kids in the robotics club how to program for the command module (the green thing) which includes an ATmega168.  Hopefully I will have it chasing down other Creates and ramming them using a little guidance theory, IR rangefinder, and a standard hobby servo.

Look forward to some example code for the command module!

Stellaris (TI) Evalbot

Next, recently TI had a deal where they sold their 'evalbot' for $25! That is $125 dollars off.  I couldn't resist, so I bought one.

Some of the features

The evaluation kit includes the following features:
  • Evaluation board with robotic capabilities
  • Mechanical components assembled by user
  • Stellaris LM3S9B92 microcontroller with 256K Flash, 96K SRAM, USB OTG, Ethernet MAC+PHY, and I2S
  • MicroSD card connector
  • I2S audio codec with speaker
  • USB Host and Device connectors
  • RJ45 Ethernet connector
  • Bright 96 x 16 blue OLED display
  • On-board In-Circuit Debug Interface (ICDI)
  • Battery power (3 AA batteries) or power through USB
  • Wireless communication expansion port
  • Robot features
    • Two DC gear-motors provide drive and steering
    • Opto-sensors detect wheel rotation with 45° resolution
    • Sensors for "bump" detection

Here is a video from TI's website!

It has been a little while, but I am still doing my nerd thing

It has been a bit since my last post, but since the school year has begun and a new season of ANTM has begun, I found myself with some time on my hands.

First off, scavenging around my garage I found a little wooden box that is the perfect size for my power window motors, a scooter battery, and my electronics.  With a little help from a dremel and a coping saw, Boom! One robot chasis.

Things were looking great, until I decided to play with the motors and hooking them straight to the battery to see how fast this thing would move.  Once I had my fun, I plugged it into the high current motor controller and Poof! Instantly I recognized the smell.  Although, it lasted for less than a second, and despite the polarized connector on the board, the battery had been connected with reverse polarity.

Here you can see the damage

Several traces got toasted.  I think the rest of the board may be okay, so perhaps with a little luck and some large globs of solder, my prototype will still work.  Unfortunately, the Xbee I had plugged in at the time seems quite dead.  Amazingly, the Arduino and Xbee shield surviving the incident.

Version 1.1 will include an N-Channel FET for reverse polarity protection, as well as some other minor changes.

I am also working on version 2.0, which will improve on both load capacities and in allowable voltages, as well as add some desired functionality.