Weekly Summary - Meghan Dang

Owned by Daniel Puratich
Last updated: 2024-08-15 by Meghan Dang
2 min read

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 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: 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

 

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 for foam plane project to integrate buck PCBAs on a system level project to test fixed wing capability ahead of

  • Compared and validated various ICs for 6s servo module project

    • efuses

    • buck

  • Attended Peggy 2 Wiring sesh

    • soldered JST connectors for OSD

  • Assembled

 

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 USB-C connectors to ensure security and stability during flight tests

    • see 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

    • 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

    • 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 using LTSpice to prevent overvoltage spikes from source impedance and ceramic caps

  • Performed second flight test of Foam Plane

  • Simplified power system on 6s servo module by selecting new components with higher input voltages

  • Presented EOT Co-op presentation Presentation Deck