P15342: Linear RF Measurement System

Subsystems Design

Table of Contents

The information shown below represents the major things we have accomplished and/or have been working on up to this stage of the project.

Subsystems Decomposition

It is important to note that the diagram displayed below is subject to change and may or may not represent components chosen for actual project implementation.

The proposed system level diagram is shown below:

Proposed System Architecture

Proposed System Architecture

Breaking the above diagram down further we can separate each outcome that must be achieved:

Subsystems Decomposition of System

Subsystems Decomposition of System

From the above diagram it can be seen that there are four major components to our system. They are as follows (in no particular order):

It should be noted as well that the green dashed box indicated by the third bullet point above ("Microcontroller and Motor Control") has been expanded to show the wiring needed for the control of the stepper motor.

Microcontroller Selection

Below is a portion of a chart taken from Adafruit comparing the different kinds of Arduinos. It can be found at the following link:


Below is the Uno and Due comparison:

Arduino Selection Chart

Arduino Selection Chart

From this chart it can be seen that the advantages that the Due has over the Uno are:

From these three things listed above it can be seen that the Due is probably the better choice.

A brief explanation of memory in the microcontroller used on avr-based Arduino boards is as follows:

The Uno has 1 kb of EEPROM. This is a negligible point to bring up in comparison with the Due. However, if the Arduino's are compared with the previous microcontroller used (Parallax Inc BS2-IC) the following is important to note:

From the information listed above it is important to see that the best microcontroller for our project is still the Arduino Due because of the numerous ways it outperforms the Uno.

Below is a capture of a chart provided by MathWorks for the various Arduino boards and their compatibility with MATLAB and Simulink:

Arduino Simulink and MATLAB Compatability

Arduino Simulink and MATLAB Compatability

From this chart it should be noted that a although the support package is shown to be listed for the Due it is actually compatible with the Uno as well.

It should also be noted that an advantage that the the Due has over the Uno is that it has interactive monitoring available with MATLAB.

Final Comments

From everything above it can be seen that the Due is the best microcontroller board to purchase.

Viewing the expanded view of the microcontoller and motor wiring diagram shown in the subsystems decomposition section it should be noted that the code uploaded was as follows:

Test Code Used to Test the Stepper Motor

Test Code Used to Test the Stepper Motor

Motor Selection

Back in the systems design phase of the design process we showed the following chart of potential motors for use in our project:

Systems Design Phase Motor Chart

Systems Design Phase Motor Chart

In the original implementation of the project the motor that was selected for use was a stepper motor. In the later innovations on our project the stepper motor that was chosen for implementation is shown above as the Anaheim Automation Stepper Motor. A key reason this motor was chosen for implementation was the fact that the motor has a built in driver thus reducing the real estate needed for mounting purposes.

A stepper motor was also chosen to continue to be used for the following reasons:

CITATION: All six bullet points above are either direct quotations or paraphrased from this document from NMB Technologies Corporation: NMBTC Step Motor Engineering

Motor Couplings

Here we must post about the motor couplings we have purchased and how we currently plan to test each one to determine the best option.

Our options currently are as follow:

Based upon these we plan to test them by building a prototype of:

System Base/Motor Mount

Proposed Base Design

Mr. Kraynik in ME shop suggests using aluminum for "hood"

MATLAB Network Analyzer Data Acquisition Code

This section of the subsystems design phase is not easily shown on EDGE. Hence, during the review with the customer a demonstration of the code will be shown in the lab.

Currently, there are some problems with understanding the data received from the network analyzer. Hence, this section of the project is still being fine tuned.

Post Subsystems Design Review Notes

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