Weekly Summary - Meghan Dang
Introduction
Brief documentation of what @Meghan Dang 's been up to each week to help in synthesis of final report and so @Daniel Puratich can visualize where the time is going and help resolve roadblocks.
Table of Contents
Related Resources
Summary
Co-op is from May 6th to August 14th.
Week 1
Started and finished WARG EE Bootcamp
Selected and created resistors, capacitors, and LDO IC to create an LDO regulator
Conducted research to determine placement of components on the PCB to maximize efficiency
Optimized layout for LDO regulator using interactive routing, polygon and via placement to increase thermal relief and reduce current loops
Researched PCB protection methods to determine necessary protective methods to optimize BOM count and price
Week 2
Started on Additional Protection Board (APB)
Selected
IC
Some resistors
nMOS
refer to 12V->5V @ 5A Buck Converter Board for additional details
Created in Altium
IC
resistors
Week 3
Determined necessary external passives for Buck board, reducing BOM count by
Calculated and selected resistors, capacitors, and mosfets to implement OVPO and RPP using equations from the datasheet
Designed and implemented an LED circuit to indicate functionality
Created custom footprints and schematic symbols on Altium for can transeiver and STM32 for ESC CAN adapter
Week 4
Buck
schematic styling
adding components
caps
resistors
verifying components
edited schematic symbols for readability
edited PCB layout
board dimensions
mounting holes
replaced initial buck IC
fixed incorrect footprints
making components
Week 5
Buck
finalized schematic
connected passives to IC
validated connections
ESC Can Adapter
made components
TVS diode
oscillator
connectors
connected components to MCU
Week 6
Researched and optimized PCB component placement to reduce parasitic impedance and cost of manufacturing
Attended and contributed to Input Filter presentation: 2024-06-08 Input Filter Introduction to further understanding on parasitic elements, resonance, and their effect on PCB design
Ran validation tests on schematics to deduce and resolve outstanding issues
missing connections
errors in netlabels
Week 7
Completed layout of Buck Board
Researched and optimized layout methods to prevent acid traps, tombstoning, and facilitate rework
Participated in simulations using LTSpice to prevent similar mistakes shown in https://uwarg-docs.atlassian.net/wiki/x/6QVllw
Week 8
Ordered Buck Board PCB using JLCPCB
Coordinated and arranged digikey order for Buck Board components
Completed placement of ESC Can Adapter
Created user manual and test procedures for Buck Board to ensure full functionality and prevent damage.
Week 9
Fully assembled a functioning buck board by hand soldering
Validated functionality on buck board using DMM, power supply, oscope, and eload
Coordinated and attended assembly sessions to produce 5 working boards using solder paste & reflow oven
Optimized layout for ESC Can Adapter
Validated output voltage for buck board to properly power Pixhawk and RPi
Week 10
Troubleshooted 2x nonfunctioning boards using DMM, power supply, and manual inspection
deduced errors were due to reversed polarity diode, and disconnected resistor
Measured efficiency of buck board using eload, oscope, current probe, DMM
calculated peak 94% efficiency
Attended Peggy 2 wiring session
Created harness for 4x escs to pdb to produce optimized connections with minimal slack
Optimized layout for ESC Can Adapter
Calculated trace width for can impedance
fixed placement of decoupling caps
Fulfilled internal purchase protocol to order pcb components
Began Foam Plane project
created power splitter connector for battery to buck & esc
created harness for buck to servo pdb
Failed connections 24x
Week 11
Completed Foam Plane build
Wired and mounted all electrical components using custom harnesses and adhesives to reduce plane weight
Configured TX12 controller and servo module using ExpressLRS to create a custom model tuned uniquely to this plane
Attended Peggy 2 Wiring Sesh
Soldered XT90 connectors for power distribution
Created block diagram of 6s servo module
Week 12
Organized and completed 2024-07-28 Foam Plane Flight Test for foam plane project to integrate buck PCBAs on a system level project to test fixed wing capability ahead of Fixed Wing 2025
Compared and validated various ICs for 6s servo module project
efuses
buck
Attended Peggy 2 Wiring sesh
soldered JST connectors for OSD
Assembled RPi Interface
Week 13
Researched and implemented passives for Buck IC to increase switching frequency and increase output voltage to properly supply power to servos
Repaired and tested 12V->5V @ 5A Buck Converter Board USB-C connectors to ensure security and stability during flight tests
see https://discord.com/channels/776618956638388305/930937310340583494/1266807916728553573 for photos and solutions to be implemented in next rev
Designed and implemented Current Sense circuit by selecting shunt resistor and RC filters to allow accurate current sensing off of 6s battery input.
Week 14
Completed final layout of ESC CAN Adapter
Created a PDN (power distribution network) using star routing methods to improve current distribution across all loads.
Optimized CAN routing using impedance and length matching to ensure the differential pairs are timing matched for accurate data reading
Selected components for 6S Servo Module Rev 1
Researched and implemented new current limiting IC to suit input voltage specs and efficiently supply 4 servos with 4 channels
Selected shunt resistor based on expected power dissipation to maximize board space and minimize losses
Stylized schematic to improve readability
learned how to read binary numbers
Week 15
Simulated input filtering for Buck IC on 6S Servo Module Rev 1 using LTSpice to prevent overvoltage spikes from source impedance and ceramic caps
Performed second flight test of Foam Plane 2024-08-14 Foam Plane Flight Test
Simplified power system on 6s servo module by selecting new components with higher input voltages
Presented EOT Co-op presentation Presentation Deck