Detailed Design Review: P18001 12-07-17

Agenda Team Vision Bill of Materials Sensor Selection Risk Management - High Risk Items Budgeting Drawings - Proposed Design Electrical Diagrams and Test Results Bluetooth Chip Selection and Test Results PCB Scheduling and Draft Schematic Power Consumption Simulation Planned Manufacturing Processes Bill of Materials Plans for next phase

Team Vision What we intended to do: What we accomplished: Determine final design and parameters for MSD2 Begin ordering parts for prototype build Complete testing on alternative sensors Construct engineering and electrical drawings/schematics Review Customer Requirements, Engineering Requirements, and Risk Management Chart to check for any updates What we accomplished: Final goal design and parameters Parts were ordered for prototype build Decided on Bluetooth chip Testing was conducted on Force Sensitive Resistors and Bluetooth chip Conducted a Power Analysis PCB schedule was drafted Budget/BOM was updated and finalized for MSD2 Preliminary schedule was drafted for MSD2 Natasha

Sensor Selection Piezoelectric FSR Replace with FSR Chris

Risk Management - High Risk Items Full document in pre-read Corey Updated high risk items outlined in red. There are others updated in handout, but they’re mostly items that lowered in importance. R20 - We recognized that a high risk would be if the strain gauge cannot withstand the strain that will be put on it. This would cause the strain gauge to not work, therefore we will carefully select a strain gauge that can withstand the necessary amount of strain. R21 - The next high risk is that the length of the string might not be adjusted correctly, therefore it doesn’t actuate relays. This risk can be minimized by carefully designing the length of the strings and how they are attached. R22 - Another possible risk is that the strings restrict finger movement and this risk can minimized by properly designing and then testing the strings to ensure there are no restrictions. R27 - The next risk is that the strain gauge delaminates from the material due to the adhesive not being strong enough or flexible enough. This risk can be minimized by doing some research and finding what adhesive will fit our needs.

Budgeting Chris

Drawings - Proposed Design of Electrical Subsystem 2D Overall Subsystem Design 3D Overall Subsystem Design Zach?

Zach?

Zach?

Drawings - Proposed Design, finger loops Mini watch bands to adjust to a range of finger circumference sizes zach?

Zach?

Zach?

Drawings - Proposed Design Thorough Sketch of Hand Strap to secure controller Silicone base of the Hand Strap zach?

Bluetooth Chip Selection and Testing Using the RN-42 chip inside the blueSMiRF evaluation board for testing Objectives: Turn on bluetooth modules Enter command mode on both modules Determine feasibility of using each command Pair modules with each other and send data Research and verify data rate and connection strength Tre?

Test Bench Tre?

Bluetooth Chip Testing Results Turned on! Command mode was enterable using UART communication Name of the device was changed using the COMMANDMODE protocol, shown at right Modules were paired with each-other (physical feedback mechanism was observed, with synced flashing LED) Sending a ‘0xC’ across the isolation barrier resulted in the LED turning on as programmed, 1000 trials, zero parity used, no errors detected Stayed connected while in use and in idle for a period of 3 hours Tre?

PCB Scheduling Preliminary Schematic: 12/05/2017 Complete 12/12/2017: Final Schematic 12/12/2017 Draft Layout 12/19/2017 Completed Layout 12/27/2017 Ordered through OSH 12/28/2017 Tre?

Preliminary Schematic (from last time) Chris

Preliminary Schematic for Prototyping Chris

Preliminary Schematic for Prototyping Chris

Power Analysis Chris

Power Analysis RGB LED: 10mA when on, ~pA when off Teensy: 35 mA nominally Bluetooth: 12.2 mA nominally ADXL: 140 uA Chris

Power Analysis Results For a >12 hour use case, we will want somewhere near 780 mAh in our battery 780 mAh is a standard size, and comes in several different package sizes, including many that will fit our design constraints Chris

Manufacturing Processes Zach?

BOM Chris

Plans for Next Phase Carry out Test Plans Review Test Plan results Determine final design based on test results Update Risk Analysis Finalize BOM and Order Construct Electrical Layout of Components Construct Hardware Components Assemble all components into Whole Test product Review Test Results Repeat Highlighted Bullets Adrita: The main focus for next semester is to build, integrate components, test, rebuild, reintegrate, retest, and so on.