The base of this robot is from RobotShop up yonder in Canadia. For the princely sum of $40 you get a plastic tub with motors, gearboxes, battery box, and cleat tread drive. I selected a grotesque yellow color in a vain attempt to match up to the yellow on the arm. But the arm is school bus yellow where the base is lemon yellow. To make it worse, the deck is buttercup yellow. The word clash would be high understatement.
To this I added an Arduino Duemenlove with ad Adafruit 4 motor controller and a Solarbotics dual motor driver with a regulated 5v output. Because the arm servos are less servo than motor and have only two power lines; this makes them motors and that’s why I’m using the AF Mshield to drive them. The Solarbotics Compact Motor Driver drives the tracks and gives the bot its motion. A single sonar range finder is hidden in the false servo compartment on the claw and tells of obstacles ahead.
Yet to do:
The Xbee units and breakout boards will show up this week. When they do, one will go on my laptop and the other on the robot. I’ll write a php based web page that permits control of the 4 axis’ of movement the arm has. I named the parts Shoulder, Elbow, Wrist, and Grip. That’s how I assigned them in the code as well, which is already preliminarily written.
On release, the robot will wait 10 seconds and then go on patrol. He moves fairly straight, so I slowed the left motor 10% in cruise mode. This causes the robot to make a wide circling type track and prevents it from repetitious movements. When the sonar finds an obstacle it will report it if the item is withing 10 inches of the robot. On the report, the motors are stopped, reversed for a second and a half, and then the right motor is reversed while the left stays forward and the motors are run that way for 2 seconds. This allows enough time for the robot to pivot at least 100 degrees, hopefully avoiding the obstacle. The program loops here, so even if an obstacle might still thwart the robot, it will merely go into avoidance mode again. It will repeat avoiding until it sees its way clear to continue patrol.
Eventually I will be able to remote control the robotic arm and gripper using the Xbee radios. I am also thingking of saving the Xbees and using an 71mhz RC radio, receiver and servos for remote control. This would permit portable control in the form of the Transmitter Joysticks.
It will be finished in a few days.
I originally built it in hopes of seeking women and having the arm automatically lift the hem of their dress as if peering under it. I abandoned this as impractical because the arm is too short to reach most womens hems.