Design of an Ethernet-based Robotic Motion Controller

[attachment=16670]
Introduction

The purpose of this report is to document the design process used to create an Ethernet-based
robotic motion controller. This core of this project will be two Atmel ATMega128
microcontrollers, linked together using dual-port RAM. One microcontroller will strictly handle
Ethernet communication, while a second microcontroller will actually interface with the motor
control circuitry and sensors.


1. Motor Control Capabilities
• 2 brushed DC motors, 12-24V supply range, up to 3A continuous current
• Connections for incremental optical encoders (otherwise known as quadrature encoders)
• Current sensing on both channels

2. External Connections/Ports
• I2C Interface
• SPI Port
• Analog to Digital Converters
• Externally available UART



Component Selection
Before we can begin to design the board, we first need to determine what components will be
used and how they will all talk together. The logical first step will be to identify the major
subsystems of the proposed board, and then chose an appropriate part; most decisions made in
the section are the product of previous experience.