[Eric Gregori] had an OWI535 toy robotic arm. Although cheap (coming it at around $30) the arm is only set up to be used via a wired control box. [Eric] knew he could do better by adding computer control via a TI Launchpad and motor driver peripheral.
The arm has shoulder, elbow, and wrist joints, a rotating base, and a gripper. All of these are actuated by 3V DC motors and have just two control wires. [Eric's] motor driver add-on for the Launchpad works great in this case. It’s got three FAN8200 dual motor driver chips on board so it can control up to six motors. Once he made the hardware connections it’s just a matter of sending the commands to the Launchpad via its USB interface, but you will also need to use a larger microcontroller than comes with the Launchpad. Here he’s chosen an MSP430G2553.
In order to make things a little bit more fun he also wrote a GUI for controlling the arm from the computer. He used RobotSee, a programming language that lets you use an image of the hardware, and overlay the controls on top of it. Now he just needs to make this into a web interface and he can have a smartphone controlled crane game.
Don’t forget to check out the video after the break.