tekdemo / RobotArmBoard

Teensy control board for the OWI-535 robot arm kit

Robot Arm Control Board

Teensy based control board designed for adding closed loop control to OWI-535 Robotic Arm Edge kit.

Setup

Power

Using the 6 D cell battery output is suggested. See assembly notes for more details.

The Teensy is not powered by the batteries, and must be provided USB power for the robot to operate.

Motors

Each motor is driven by a pair of signal pins signals from the Teensy. Setting one HIGH and the other LOW will result in moving the motor, and thus each joint.

• Pins 10 and 9 control M1, opening and closing the claw.
• Pins 6 and 5 control M2, the "wrist" joint
• Pins 4 and 3 control M3, the "elbow" joint.
• Pins 20 and 21 control M4, the "shoulder" joint.
• Pins 22 and 23 control M5, which rotates the arm
• Pin 13 controls the light on the claw end. This is the same as the Teensy's built in LED.

Analog Feedback

For closed loop feedback, the following pins are available:

• Pin A1 corresponds to M1's potentiometer.
• Pin A2 corresponds to M2's potentiometer.
• Pin A3 corresponds to M3's potentiometer.
• Pin A4 corresponds to M4's potentiometer.
• Pin A5 corresponds to M5's potentiometer.

Note, each potentiometer "tuning" will be somewhat different, and require some setup for each robot and each joint.

Controller Input

The controller uses the same analog pins as the Analog feedback. As a result, it's not simple to use the controller for input when the analog feedback is plugged in. However, doing so will not harm the electronics.

• Pin A1 corresponds to M1's joystick.
• Pin A2 corresponds to M2's joystick.
• Pin A3 corresponds to M3's joystick.
• Pin A4 corresponds to M4's joystick.
• Pin A5 corresponds to M5's joystick.
• Pin A0 corresponds to the Light slider.

Due to the joystick construction the joystick will only generate a few values. When read using AnalogRead, you will get roughly 512 when the joystick is idle, and around 1023 or 0 when the joystick is pressed.

The LED switch is wired up to it's own unique input, and can be used alongside a closed loop input without issue. The LED switch will be around 512 when off, and 1023 when on.

Assembly

Power Input

Motors

Controller Input Section