RobotBuilder

School Servo Project

This servo project was created for my Embedded Systems class in Fall 2004. It is designed for controlling servo motors serially from a computer. Its purpose was for controlling two arms on a balancing uBot with 3 degrees of freedom in each arm.

Servo Testing

The servo project is breadboarded and connected to a laptop.

Oscilloscope Pictures

Servos take a pulse between 1 and 2 ms in length as an input for a commanded position. Here are some pictures at 1 ms/div horizontal and 1 V/div vertically of the output of one channel of a scope. Pictures show a 0.6 ms pulse, 1.5 ms pulse, and 2.4 ms pulse.

Pulses are sent at 50 times per second (10 ms/div here) when enabled.

VB Demo Software

Here's software I wrote to demostrate the servo project was working. It also has position and torque feedback not shown in this early screenshot.

Final PCB

The working project was put onto a small printed circuit board. It only requires a 12 V battery and serial port connection to control up to eight hobby servos. It has feedback for position and current.