P18317: Precision Optical Transducers Test Bed

Customer Handoff & Final Project Documentation

Table of Contents

Team Vision for Final Demo and Handoff

This phase can be broken down into two sub phases: before and after the customer review. Before the customer review, our team's goal was to get one wavelength fully tested and functional inside the box. This included deriving equations, populating the board, minor software fixes, linearizing the results, recreating a new laser driver circuit, populating a project board, and adding components to the physical design such as holes for cables. The second part of the phase was focused on (and is focused on) completing the modified customer requirements that are shown in the Functional Demo Materials section.

The team delivered a working 1550 laser circuitry, if the customer follows the teams advice and uses the serial software, as well as a tested and working 1310 system that requires a replacement laser. The team also delivered the documentation needed to create a working 850 system as well as the technical documentation for the box.

Test Results Summary

The aim for our systems tests was to be able to accurately measure the attenuation of an attenuator at the 1550nm, 1310nm, and 850nm wavelengths.

All tests that were run and their results are shown in the test plan document below.

Test Plan and Test Results

1310 Outputs and Results

Equations to obtain the optical power from the voltage read by the arduino were generated.

1310 Equation Generation

The following data was captured and compared to the theoretical results.

Measured Attenuation 1310

Measured Attenuation 1310

This data:

It was observed that:

Linearization was implemented, but the laser broke before data could be collected.


1310 Laser is broken :(

1550 Outputs and Results

The 1550 system was characterized by sweeping the attenuation using a VOA and capturing the voltage read by the Arduino. From this plot the optical power can be calculated using the equations given below.

1550 Equation Generation

Voltage at Output of Pout Circuitry vs Set Attenuation

Voltage at Output of Pout Circuitry vs Set Attenuation

Progress on Functional Demo Goals

By probing the ADC pin with an oscilloscope the following data was collected:

Comparison of Noise with and without touchscreen

Comparison of Noise with and without touchscreen

The LCD was identified as being the primary source of the 1550 Pout Variance

With Touchscreen

With Touchscreen

Without Touchscreen

Without Touchscreen

The laser was analysed using an Optical Spectrun Analyser and it was noticed that the spectrum changed with time. A video showing this change is shown here: 1550 Optical Sprectrum

Final Project Documentation

The Software Design Documentation can be found at this link: Software Design Documentation

The Final commented combined software can be downloaded at this link: Combined Software

The Final Serial Software can be downloaded at this link: Serial Software

The datasheet can be found here: Technical Datasheet

The link to the team's technical paper : Technical Paper.

The link to the team's final poster: Poster.

The PCB Schematic can be downloaded at this link : PCB Schematic.

Due to the time and budget constraints of the project, many additions to the software were out of reach for the project. However, these additions are listed as recommendations moving forward. Additions that can be made to the software environment are: adding a state saving code that will allow the user to upload to the last saved state the device was in to facilitate integration with automation, as well as a closed loop version with data validation control with the voltages and optical powers read by the device. Likewise, the possible integration of a second Arduino and a second set of hardware so that serial testing and touch screen testing can occur simultaneously.

Designing a laser driver circuit is harder than anticipated. It would be recommended to purchase one off of the shelf. Also the team would recommend some redesign so that the electro-optical circuits are shielded from the effects of the Touch Screen.The team would also recommend a deeper dive in to ESD protection for all devices in the box. As well as the completion of the 850 circuits all well as repurchasing the 1310 laser to achieve maximum intended functionality.

Functional Demo Materials

The action items from the review can be seen down below. Our final tasks as to complete these action items. So far we have made significant progress on the technical root cause analysis and have made reasonable progress on the documentation.

Overall the customer was pleased with our results and understanding concerning the technical difficulties we ran into.In order to meet these final requirements we have been communicating with Precision regularly through update emails.

Phase Requirements

Phase Requirements

Plans for Wrap-up

Elizabeth's Three Week Plan: Three Week Plan

Home | Planning & Execution | Imagine RIT

Problem Definition | Systems Design | Preliminary Detailed Design | Detailed Design

Build & Test Prep | Subsystem Build & Test | Integrated System Build & Test | Customer Handoff & Final Project Documentation