Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Received components selected last week (e.g. current sources, 32:1 multiplexers, and 16 bit ADC) and appropriate prototyping hardware needed to adapt surface mounted components to a breadboard. Completed validation of selected current sources and sensing circuits, all test results were as expected. The wrong breadboard adapters for the 32:1 multiplexers were shipped delaying validation of the multiplexers, issues related to the order were corrected and the required adapters are en route. Battery and power management/charging components were selected and ordered. Original risk reduction was done using an Arduino and included 10 bit ADC, Beaglebone Black and 16 ADC have arrived. Development of a codebase for the Beaglebone has begun. Configuration files, ADC SPI, and operational code files need to be developed for our project. Component selection from last week has also enabled progress towards design for the PCB layout. Schematic design and board layout is underway and will be sent off for review once individual component validation is completed.
Accomplishments from Previous Week
Soldered Current sources, current sensors, ADC, and shunt resistors to breadboard adapters. Received 32:1 multiplexers but wrong adapters were shipped prohibiting validation at this point. Correct adapters are scheduled to arrive 4/13/2018.
Built prototype circuit using soldered components and breadboard. Used Arduino and 8:1 multiplexers to capture data and validate operation of current source and sensing circuits. Further observed component operation using digital oscilloscope and digital multi-meter.
The 16 bit ADC was received and soldered to prototyping adapter. Code development to interface with Beaglebone was begun.
BeagleBone was recieved and codebase development was started, including a configuration file with truth tables for 32:1 multiplexers and sensing skin sampling configuration arrays.
Created slide deck, updated gantt chart, and practiced for design review presentation.
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Interface ADC with BBB using SPI and perform component validation (Max)
Implement and test battery and power mgt. system, validate operation of components (Matthew)
Develop 'C' code for switching and logic using beaglebone black, validate 32:1 multiplexers(Aaron)
Finalize schematic for PCB layout and send out for first review (Jacob)
Select external connection for sensing skin and charging port (team)
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Ken recommended implementing a voltage regulator and logic to stop taking measurements when the battery runs low. This was already part of our design but greater emphasis will be placed on it.
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
(4/4/18) Jerry and Pedro raised concerns on our ability to effectively solder surface mounted components to custom PCB and recommended looking into PCB manufacturers early, as lead times can be longer than a week. We have taken these comments into consideration and are expediting our PCB layout design.
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
N/A, no new peer comments
Risks and Areas of Concern
Complexity of interfacing ADC with BBB.
Settling time of components during fast switching.
PCB layout of ADC, proximity of GNDs, EE review of schematic and PCB layout will provide closure
Resources or Information Required but not Available
32:1 multiplexer adapters were delayed
Schedule
Wednesday, 4/11/18: Design proposal presentation
Friday, 4/13/18: 32:1 MUXs and Battery components should arrive for validation
Wednesday, 4/20/18: Meeting with Ken
Budget (list amount spent and amount remaining)
Amount spent: $71.90
Amount remaining: $1080.49
Progress on Report and Webpage
Report is underway
Webpage content is being updated daily with documentation from project development
Webpage home page edits will begin this week