Let's Make Robots!

Project2501's blog

RFBees and AVR Watchdog Timers...bark!

In my last post I mentioned using RFBees for a communications link between a remote sensor and a laptop PC. During my testing, the RFBees would become unresponsive at random intervals for some reason.

Wireless winter weather wonders - weather prediction with a swarm of *Bees

Here's a little project I've put together using a bunch of components from Seeed Studio:

Wireless Sensor Node

For Halloween I Gave My Robot a Brain, or Fun With a Backpropagation Neural Network

I’ve long been fascinated by the concept of artificial intelligence and its application to robotics.

CNC machine smoke testing

My goal was to draw something in a CAD program, import it into Mach 3, and let the machine move through its paces to see if anything fell off, went up in smoke, caught fire, etc. I've attached a (crappy Blackberry) video of one of the first few times things worked as expected.

CNC - my summer obsession

Haven't posted anything for awhile - I've been busy building a CNC machine based on this book: Build Your Own CNC Machine (see http://buildyourcnc.com/Book.aspx for more details). The book very thoroughly describes the building techniques necessary to get up and running using the plans in the book and the suggested electronics.

Here are the basic materials I used (exact electronics specified in the book):

C328R camera and Arduino

Well I've decided to replace my 2.4 ghz wireless camera on Ardbot with this guy:

JPEG Color Camera - UART Interface

While it isn't as capable as the video camera I had planned to use, it has the advantage of having a serial interface that can communicate with the Arduino, uses 3.3v, so my hope is to be able to stream the JPEG images via XBEE to my PC.

Annoying servo jitters (resolved?)

I noticed some extreme jerkiness between the ardbot's pan/sweep servos and any interaction with the bluetooth modem. My original code was using the Servo library that ships with the Arduino IDE. Switching to the SoftwareServo library (see http://www.arduino.cc/playground/ComponentLib/Servo) seemed to resolve the jitters....although I can't really explain why at this point.

Reading characters/strings with arduino serial port

Finally, I can send and receive messages between the ardbot and my pc, over bluetooth. This post on the Arduino forum was very helpful:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1231650517

Arduino, Bluetooth, Linux continued....

Bluetooth, java, Linux - seem to be working together in harmony now. Some things I learned along the way regarding the RXTX java library and Linux com ports in general:

By default, only the root user has access to read/write the serial ports on the system. So if I take the sample code from RXTX I've attached called FindPorts.java and run it from the command line with my user account it will not list any ports. This code was lifted straight from the RXTX site. I've packaged it in a jar file for ease of use from the command line:

Arduino, Bluetooth, Linux

Back to work on the Ardbot. I've decided to build my control panel competely in java/JavaFX on Linux. One challenge was getting my Bluetooth connectivity going on Linux with this configuration:

  • Kensington USB Bluetooth dongle on Fedora 11 PC
  • Sparkfun  Bluetooth modem on robot

My goal will be to control the robot from a gamepad controller attached to the PC, wirelessly over the Bluetooth link.