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Integrated System Build & Test

Table of Contents 1 Team Vision for Integrated System Build & Test Phase 1.1 Plans 1.2 Accomplished 2 Test Results Summary 2.1 Software 2.1.1 Web Application 2.1.2 Controller Board 2.1.3 Raspberry Pi 2.1.4 Database 2.2 Electrical 2.3 Mechanical 3 Risk and Problem Tracking 3.1 Software Problems 3.2 Electrical Problems 3.3 Mechanical Problems 3.4 Docs 4 Functional Demo Materials 5 Plans for next phase 5.1 Important Team Dates 5.2 Individual Plans 5.2.1 Brittany Lacy 5.2.2 Max Reitz 5.2.3 Robbie Frumusa 5.2.4 Josh Metzger 5.2.5 Isaac Garland 5.2.6 Jimmy Cummings

Team Vision for Integrated System Build & Test Phase

Plans

• Perform impact tests on helmet
• Put finishing touches on test rig
• Continue work on web application
  • Implement player page
  • Add way to tell if player receives concussion
  • Finish login and registration page
• Run stress tests on database
• Run stress test on Raspberry Pi
• Troubleshoot voltage issue
• Finish necessary additions to the charging board for its integration

Accomplished

• Web app player page has been almost entirely implemented
• Login and registration pages implemented
• Simple detection check to flag a conclusion
• Performed stress test on database and Pi
• Test rig completed to the point where tests could be performed
• several testing runs were performed
• Verified the charging capabilities and voltage output of the charging board

Test Results Summary

Software

Web Application

• Tested time to call and perform database procedures while implementing the application further
• Updates to the web application includes:
  • Fixes to nav-bar to avoid skipping login page
  • creation of home pages for each user type
  • Fixed nav-bar to direct to correct home page based on user type
  • Added 'Add' and 'Edit' buttons to home pages
  • Added table coloring based on Gfelt value obtained
  • slimmed down table information, and added button to direct to details page

Controller Board

• Changed how the controller reads from the accelerometer
  • Initially the controller read all of the X readings followed sequentially by all of the Y reading and then all of the Z readings
  • It is now changed to read every axis at the same time.
  • This change helped get more accurate results when testing.

Raspberry Pi

• Tested Raspberry pi Ethernet capability
  • Used python application to send UDP packets to Raspberry pi while it was also receiving packets form the collector
  • the DB would then keep track of how many packets were received from the collector unit to track if there were any lost due high usage of raspberry pi
  • the results from this test are shown below. Increasing the stress on the raspberry pi's Ethernet adapter did not cause it to drop any packets. There were no packets dropped because of how the Ethernet interface is configured on the raspberry pi. It is designed to be able to store data that is received until the application it is being sent to is ready to receive the information.

Database

• Continued to implement new procedures required for web application
• Stress Tested Amazon Database for read performance
  • Before the test was executed, 300 data points were inserted into the History table for sensors 1 - 200
  • 2 python scripts were then created. the first designed to start a variable number of threads that would request every entry from the history table for a specific sensor ID between 1-200. This script put the load onto the database
  • The second script was designed to request all of the information from the history table of a different sensor than the ones in the stress test application. This script would return the time that it took to complete the command in seconds. The results for this test from 0 - 50 users is shown below.

• Stress Tested Amazon Database for Write Performance
  • The Pretesting conditions were the same for the read test, there were 300 data points inserted in the history table for sensors 1-200
  • the Stress python script was the same as the writing test to put a load on the history table
  • the second script will insert data for sensor 101 with random data. The test results are shown bellow.

Electrical

• Tested the charging capabilities of the PCB when attached to the assembled battery pack
  • Created a mock set-up for drawing current from the battery using a set of LEDs
  • Discharged battery from 3.70V to about 3.45V
  • Charged it up to 3.50V
  • No noticeable heating of the batteries during the charging and discharging of the batteries. Minimizes safety concerns regarding the possibility of overheating inside the helmet from usage.

• Connected the leads of a multi-meter in series with the battery to measure current drawn to and from the battery.

• Current draw from the board when the regulator and charging IC are in use.

• Several LEDs were attached to a bread board in parallel to discharge the batteries.

• Current draw from the discharging set-up.

• Charging rate goes from 500mA to 100mA after exceeding 3.50V. Battery reaching full capacity, so a slower rate reduces the chance of the IC failing and overcharging the battery.

Mechanical

• Hitting Max G force at about 47 cm
• Ear Impact is more of a step function: Possible ME errors:
  • Noticed clip by string readjusted after a drop which changed the height by 3 cm. Easily avoided when looking for it.
  • More difficult to have exact placement. Needs some modification.
  • Height could not be as exact with only one person adjusting the test rig.

Risk and Problem Tracking

Software Problems

• Ran into an issue with the DB where it will not allow more than 65 connections
  • This is due to the hardware configuration that the server has. Since there is only 1 core it is limited to 65 connections.
  • If the hardware is updated to a quad core machine it will allow 512 users.
• Changed the way the sensor takes it accelerometer readings.
  • Before it would take all of the X samples then all of the Y samples followed by all of the Z samples.
  • It is now changed to take each sample sequentially so the readings are more consistent with the impact.

Electrical Problems

• Testing showed that the charging IC requires an input of specifically 1.60V to enable the use of a micro-USB input for charging. Based on the datasheet, this was believed to just require a “high” input of more than 1.40V.
  • Ordered a regulator to take the 5V input from the USB and send 1.6V to the pin.

Mechanical Problems

• Easily adjustable string/strap rather than hand knotted string for adjustable height.
• Initial epoxy attachment had a bad mix – more careful handling and addition of screws
• Redesign Board cover – initially slightly too small for new board

Docs

• A link to the most recent risk management can be found here
• A link to the most recent problem tracking can be found here.

Functional Demo Materials

A link to the pre-read document can be found here.

Plans for next phase

Important Team Dates

• Debrief Paper/Poster 3/29
• Poster draft due 4/5
• Ethics Survey 4/9
• Paper Draft due 4/12
• Robbie Gone 4/11-4/15th
• Team Meeting Thursday 4/19
• Poster due 4/19
• Customer Hand-off 4/24 at 12PM
• Paper due 4/23
• Imagine RIT 4/28
• Gate Review 5/2-4

Individual Plans

Brittany Lacy

• Order items for Imagine
• Double Check Imagine documentation/proposal
• Continue testing different heights/angles
• Attach 200G accelerometer, continue testing
• Update draft of paper

Max Reitz

• Increase rig height.
• Update test plans to accommodate initial data findings.
• Test helmet at prescribed locations and heights.
• Finish Imagine RIT poster.
• Build table to hold helmet for Imagine display.
• If time permits, complete temperature testing.

Robbie Frumusa

• Assist Josh with completing the web application and the DB functionality that interacts with the
• Assist Mechanical team with testing accelerometer
• Work with team on poster for imagine and final paper
• Make the python applications auto start on power on

Josh Metzger

• Test edit player page
• Implement details page
• Finish about page
• Finish contact page
• Add cell coloring to table for both battery voltage and concussion
• Add color scheme for entire app
• Begin implementing coach page and all its aspects
• Begin implementing observer page and all its aspects

Isaac Garland

• Finish adding the necessary components to the board for full integration with the helmet.
• Test how long it would take the battery to charge from 2.8V to 3.7V
• Work with team to integrate the battery and board into the helmet.

Jimmy Cummings

• Assist in data collection and helmet calibration
• Oversee Temperature testing
• Continue working packaging science to get calibration measurements
• Write concussion background paper
• Finalize equipment attachment inside helmet.

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