Build & Test Prep
Team Vision for Build & Test Prep PhaseSummarize: In the few short weeks since our last design review, our team desired to work on the structure and review/finalize our custom PCB schematic. We also wanted to start the PCB layout. At this point in our design, the schematic is done; it has gone through peer and professor review. Next, we will be placing components and performing layout. In addition, the structure for the HAB has been further refined, and prototype building will begin soon.
Custom PCB UpdateThe updated schematic can be found here: Main COMMS Board Schematic
The following changes have been made since the last review:
- Added title page with table of contents
- Added block diagram
- Added hardware watchdog timer
- Modified 12V boost portion of schematic for more current (for ATV Transmitter)
- Added GPIO control to OSD 12V power
- Added ferrite beads to I2C lines by GPS module
- Created separate analog and digital grounds
- Labeled more component parameters (like voltage rating of capacitors, etc.)
- Added Pi GPIO LED
- Switched to SL and Mini-fit Jr. Connectors
The updated custom PCB BOM can be found here: Main COMMS Board BOM
We have started a rough placement of components for the layout of the custom PCB:
Build/Assembly Part Number Assignments - For Testing Purposes
For 'callouts' in mechanical test plans the following part numbers have been assigned to the manufactured mechanical components.
Part 'M2-1' will be attached to a central line/connection point using 1/4 inch Wet Environment Rope. M2-1 allows for eight connections points, each with a harness tensile strength of 800 pounds. The individual connection points on M2-1 can each withstand a maximum bearing load of 250 pounds before reaching the yield point of the material - to be verified in testing. The approximate cost of the rope (25 ft) will be roughly 35 USD. Rope clamping methods are under review.
Test Plan SummaryThe goal of our test plans is to document how we plan to test the various subsystems that make up this HABIP. Due to the nature of the final product, many of the subsystems can be tested completely independently from the rest of the system. Therefore, test plans have been written for different pieces, such as the APRS, ATV transmitter, the OSD data overlay, general data storage, weight, thermals, and structures. For each of these aspects of the design, a test plan has been written to ensure the engineering requirements laid out in the planning phases of the design are kept.
List of Test Plan Documents
- Analog Video Overlay
- Collected Data Storage
- 2m Transceiver
- Static Mechanical Design Properties
- Harness Extension Test Plans
- Impact Test Plans
Here is a replication of our engineering requirements for reference:
In Flight Testing:
- ER 3.1 - Duration : Can approximate prior to flight by running system for the desired time.
- ER 3.3 - Elevation : Can approximate prior to flight, however is a direct causality of balloon selection and system weight.
- ER 3.4 - System Failure : Cannot really be tested. It will be a success if the system survives the flight.
- ER 3.6 - System Recoverability : We will test the APRS system and the DAQCS team will test the GRSS system. It will be a success if the system is recovered from the flight.
- ER 2.5 - System Thermal : Can approximate prior to flight, however no appropriate environment for direct testing.
- ER 2.6 - Weight Per Quadrant - Design is complete; requirement was an antique of previous design theory.
- ER 2.3 - Disturbance Mitigation - Design is complete; requirement was an antique of previous design theory.
Risk and Problem Tracking
The working document can be found here.
Problem TrackingHere is our problem tracking table:
Here is a pie chart with our progress on these problems:
The working document can be found here.
Design Review MaterialsThe following presentation was given on February 2, 2017: Build & Test Prep Design Review Presentation
Notes from the design review can be found here: Build & Test Prep Design Review Notes
Plans for next phase
Our Gantt chart working document can be found here: MSD II Gantt Chart
A list of team tasks for the next phase can be found here.
- Adam's Phase 6 Individual Plan
- Connor's Phase 6 Individual Plan
- Ian's Phase 6 Individual Plan
- Matt's Phase 6 Individual Plan