Hacking the OWI535 Robot ARM Using RobotSee, the TI Launchpad,
and the EMGRobotics Six Pack Booster
by Eric Gregori (www.EMGRobotics.com)
You can download all the firmware and RobotSee code used in this article from here:
www.robotsee.com/Launchpad_SixPack_Booster/SIXPack_OWI535_RobotSee_Project.zip
The OWI535 robot ARM is an educational toy manufactured by OWI. The ARM has four degrees of freedom and a gripper. All four joints and the gripper are controlled by small three volt DC motors.
http://www.robotshop.com/owi-535-robotic-arm-edge-3.html
As shown above, normally the robot arm is controlled by a manual wired controller. Each DC motor has two wires coming from it, that plug into an adapter board that then connects to a manual controller. Since both wires from the motor are available on (0.1" headers), hacking the arm is incredibly easy.
Programming/Controlling the ARM Using RobotSee
RobotSee is a free programming language and part of the Robot Vision Toolkit. RobotSee is as easy as BASIC, with the power of C. Using RobotSee you can write simple graphics based programs for controlling anything over a serial port. The above image shows the RobotSee tool with some RobotSee code in the upper left corner and the graphic application controlling the arm in the lower corner. Using RobotSee you can easily customize your graphics application to look however you want.
A simple Graphics Application Used to Control the Arm via the TI Launchpad and Six Pack
The above graphic application allows the user to control four of the five motors by simply clicking on the up or down arrows. Click the arrow start the motor, clicking the red box stops the motor. This graphic application was written in 30 minutes using RobotSee.
EMGRobotics SixPack Booster plugged into TI Launchpad
The SixPack Booster from EMGRobotics plugs into the TI Launchpad and can be used to control up to six small DC motors. The TI Launchpad is a $4.30 development system similar to the Arduino. The TI Launchpad has made a big mark in the hobbyist/DIY industry by being a very low cost, high quality development board. The TI Launchpad is supported by a large Wiki, and a huge amount of projects. The TI Launchpad includes a built-in USB to serial converter. This creates a virtual COM port on your PC whenever the TI Launchpad is plugged in.
The Six Pack Booster plugs into the TI Launchpad and up to six low power DC motors. The direction of each DC motor can be controlled independently, using two signals each from the Launchpad. The motor drivers are FAN8200's. Each FAN8200 can control two DC motors. The Six Pack is ideal for use with 3 volt motors. The FAN8200's can be used with 6 volt motors but that is close to the limit of the FAN8200's capabilities. The three volt motors used in the OWI535 ARM are ideal for the Six Pack board.
Click Here to Learn more about the EMGRobotics Six Pack
The firmware for the EMGRobotics Six Pack is free and Open Source. You can modify it to do whatever you would like. You can add digital or analog sensors, you can add buttons, you can even add more TI Launchpads using I2C. robotSee is also free, and can be downloaded from here: www.buildsmartrobots.com. The RX and TX lines on the launchpad are available. Simply remove the USB to serial RX/TX jumpers and you can control the robot arm from any 3.3 volt TTL controller (add a resistor divider yo use with Arduino).
Control your OWI535 using any software that can send character through the serial port. You can control the arm using C, C++, .NET, C# or Python. You can even manually control the arm using hyperterminal.
Where to get the parts:
The OWI535 is available from:
http://www.robotshop.com/owi-535-robotic-arm-edge-3.html
The TI Launchpad is available from:
http://e2e.ti.com/group/msp430launchpad/w/default.aspx
The Six Pack is available from:
http://buildsmartrobots.ning.com/group/emgrobotics-six-pack-ti-launchpad-booster
You can download the Robot Vision Toolkit with RobotSee from:
http://www.robotsee.com/RobotVisionToolkit.zip
To control all five(5) motors you will need to get a MSP430G2553IRHB32TMSP430G2553IRHB32T. You can order one from TI (free sample) or direct from Digikey.
You can download all the firmware and RobotSee code used in this article from here:
www.robotsee.com/Launchpad_SixPack_Booster/SIXPack_OWI535_RobotSee_Project.zip
Any question, check out the OWI535 group on www.buildsmartrobots.com (http://buildsmartrobots.ning.com/group/owi535).