Electrical Engineers	Computer Engineers
Brian Taylor	Elier Bermudes
Noah Madison	Daniel Sypioe

Project Description

During Senior Design I & II we created a functional prototype of a portable software-defined field radio based on the LimeSDR, an embedded system, as well as any necessary components that are required to complete a functional prototype

The device will feature a speaker, microphone, and push to talk button which will enable the consumer to listen to their favorite AM/FM stations as well as communicate with others on FCC regulated wavelengths. It will also feature a touch screen to visually display the necessary functions and features of the radio. This will include separate pages to access regular listening, communications, a waterfall display, a settings page, as well as a signal bar on the right hand corner of the screen. In the final stages of prototyping, measures will be taken to make the product water-resistant to sweat and mild water droplets allowing the device to be taken outdoors without risk of damage due to weather or accidents.

The most critical aspect of our device is the combination of our embedded system, radio receiver, and amplifier. The Raspberry PI and Lime SDR must be integrated seamlessly and in a way that is computationally efficient in order to reduce any disruptions to service. The amplifier on the other hand must be selected carefully since a number of factors can affect its performance such as the input/output impedance, heat dissipation, and the type of filter it uses.

Sponsor

University of Central Florida Amature Radio Club

This project is funded up to $500 by the Amature Radio Club in hopes that we can not only develop the system but create one that is easily accessible and upgradeable by the average entry-level Amature Radio enthusiast without the use of specialized components or software. We hope to not only exceed the expectations of our sponsors and advisors with the final prototype but to create an affordable device that will encourage generations of engineers of all backgrounds to enter the field of Amature Radio.

Initial Project Description & Block Diagram

The block diagram figure provides a generalized diagram of all of the features of the device and how they should interact at a hardware level. The embedded system is further elaborated on in the upcoming sections. The battery control circuit, although necessary for the functionality of the system, will not be a part of the actual handheld and will be external to the system. This diagram in particular is for a high abstraction explanation of different features that will exist and how they are to interact with other project features and systems. It is not meant to be an exhaustive description of every component, but more of a summary. Provided below the figure is the legend which outlines the division of labor for this project in all stages including research, design, integration, prototyping, and development.

EEL 4914 - Senior Design I

During Senior Design I, we completed most of the necessary research and documentation needed to begin developing a prototype of the Field Radio. This encompassed tasks such as meeting with advisors and sponsors to ensure that the project was going smoothly and that all changes that needed to be made to the final requirements were approved. We also completed a virtual part comparison as well as an initial part selection. As you will see in the CDR and final demonstrations, we did have to use upgraded major components due to the current parts shortage as well as having some parts fail due to unexpected overcurrent issues on the final day of testing.

To the right is a download link for the documentation from Senior Design I.

EEL 4915 - CDR

During Senior Design II, we were tasked to create a Critical Design Review (CDR) which allowed us to outline the reasons as to why we chose the components and methodologies we did. We also updated the CDR for the Final Presentation in order to elaborate on the aspects of our system that did not perform well during a stress test, as well as all of the subsystems that failed from unpredictable circumstances such as overcurrent instances. Most notably during the filming of our Final Presentation, the touchscreen drew more than 1 Amperes of current which lead to one of our voltage regulation subsystems to fail critically. Despite this, we were able to work through the night and recreate the failed subsystems in order to finish the final presentation on time. Due to this, you will see in the Final Presentation section that we have updated the final video since our presentation so that we provided the best quality content to our peers, advisors, sponsors, and future engineers to come.

EEL 4915 - Conference Paper

This conference paper elaborates on the methodology and design implemented in order to develop a portable software-defined field radio based on the LimeSDR, an embedded system, as well as any necessary components that are required to complete a functional prototype. This paper provides the reader with our component selection for each subsytem as well as all major notes in the development of our system. Since this project was expected to last multiple Senior Design sessions or to be continued by the Amature Radio Club, we include some thoughts and next steps on creating a casing as well as heat management.

To the right is a download link for the 8 Page Conference Paper.

EEL 4915 - Final Presentation

We have succeeded in creating a portable system concept equipped with Lithium-Ion batteries with a charging circuit, an embedded system for radio receiver communications, simple TX/RX transmissions, and a fully functional touchscreen with audio I/O support. We are currently working on finalizing the development of our transmission protocols as well as constructing a GUI capable of being updated by our sponsors once the system is delivered.Despite the numerous challenges we faced along the way ranging from trying different methods of remote software development, complications with component testing, and getting RX/TX transmission set up; we were able to overcome most of our obstacles and what we could not we improvised and allowed for slight changes in the overall requirements when new information was presented.

To the right are links to the Final Demonstration Slides as well as the video presentation/Final report.

EEL 4914/4915 - Extras

To download all of the associated files for this project, please click the link to the right.

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