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.
1310 Outputs and Results
Equations to obtain the optical power from the voltage read by the arduino were generated.
The following data was captured and compared to the theoretical results.
- Represents the full range of attenuation that the fixture was capable of measuring
- Illustrates a similar trend to the theoretical expectations
It was observed that:
- The measured data became nonlinear in the region with high attenuation
- Adding calibration and linearization could correct the plot and help it align with theory.
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.
Progress on Functional Demo Goals
- 1550 Pout failure was due to a misplaced jumper wire on the breadboard. Silly mistake, easy fix. Pout is now reporting the voltages we would expect.
- The 1550 Laser Driver circuitry was examined with a current probe to check for high in-rush current. Unfortunately the probe was 30 years old and we can't trust the results we were seeing
- The 1550 Pout Variance was investigated. Pout voltages were collected with the screen on and with the screen off. Variance in the data with screen on was noticeably higher than with screen off.
By probing the ADC pin with an oscilloscope the following data was collected:
The LCD was identified as being the primary source of the 1550 Pout Variance
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 DocumentationThe 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 MaterialsThe 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.
Plans for Wrap-up
Elizabeth's Three Week Plan: Three Week Plan