Macrofab Engineering Podcast

MEP EP#344: Fierce Key InventoryDifferential probe design update Trying to reduce part count - Want to make it simple Decided to go with Caddoc 1776-C681 resistive dividers. Used this on the bias test system 1:100 divider with high voltage, good tolerance and good thermal performance Challenge is to get the dividers to fit 3d printed case Air Filter / Canister Turned out great so far will have to see how it holds up under the heat Pictures on the blog Digikey Newsletter Check Out Digi-Key’s Stock of Toshiba’s Power Management and Circuit Protection Products Email received at 8:25 AM Sold out by 9:14 AM  Toshiba TPH9R00CQH

MEP EP#343: Bricking BadBricking Microcontroller - Watch those fuses Pic, AVR, STM Atmel ATXMEGA16A4U AVR studio and microchip studio AVRDUDE Air Filter / Canister Long Running Project between Chris Kraft and Parker Mods on the red Jeep necessitated moving the original air cleaner First design was all 3D printed around 2016 / 2017 This is right around when 3D printing large objects like this started to get fessable on a hobby printer PLA glass fiber Worked but the material couldn’t handle the underhood temperatures Second design was welded together out of steel Material was due to tool and cost constraints Working to this day Used a filter that is not manufactured anymore Third design is a combination of everything Parker has learned about 3d printing Polycarbonate seems to hold up in under engine bay temperatures Endcaps printed in this material Heat set brass inserts for screws Aluminum mounting brackets for 3” hoses  Carbon fiber for the main body

MEP EP#342: Hackery ExpertsHyR0n Mathematician Computer Scientist AND!XOR employee of the month Working on badges and things Hackery Previous Podcast Episodes Incognito Mode episode number 69 Arduino, The Gateway Drug To #BadgeLife episode number 109 Espress-ify? Designing Products Around the ESP-32 Platform episode number 144 Feel the Hum episode number 183 Better Encryption than Zoom, Firmware Stacks episode number 238 And a couple of the Starwars Specials DEFCON 30 AND!XOR Badge Its a watch, with some watch things, hacker apps (TV B Gone, BLE Interrogator), Games, & Challenge Give them away for free at DEF CON following sponsorship from companies and philanthropists. Off the shelf device with hacked firmware LilyGo T-Watch 2020 V3 But how did we get there? A story of supply chain woes Original Watch idea - supply chain issues and crazy costs / quantity buy requirements Look at consumer watches we could hack (PineTime, then LilyGo) It wasnt just software, a true micr

MEP EP#341: Project Snackey RecapProject Snackey at Defcon30 What we did CTF Codes What went wrong What went right People’s reactions Improvements for next year Lock Picking Village Hardware improvements Physical Security

MEP EP#340: Necrobiotic SynthesizersProject Snackey See y'all at defcon 30! Stuff you want to learn about? Canbus FPGA design AWS web development Manim - python My Spider-sense is Tingling Spiders are just hydraulic animals

MEP EP#339: Educated CompromisesProject Snackey Announcement video lands before this podcast gets released. Project Diffprobe Looking at teardowns of other diff probes ADA4817 2pA input bias -3dB bandwidth of 1050MHz Very low input capacitance Combine to make an instrument amp Perhaps going with an integrated instrument amp INA12 Page 27 of the datasheet -  Right-Leg Drive Hardware subscriptions? BWM to offer heated seat subscription 18/mo 180/year 300/3year 415/unlimited These subscriptions are for “luxury” items in the car, what is next? Subscription based displacement?  Displacement as a Service - DaaS Thanks I hate it.

MEP EP#338: Feature Complete or Minimal Viable ProductsProject DiffProbe Landed on the topology Stephen wants High voltage dividers Compensation capacitors CMRR calibration (120dB rejection) Offset correction Buffers and Instrumentation Amplifiers Differential Stage 10x and 100x attenuation means offsets have to be bang on Opamps (3 of them) Buffers Low input bias current Low offset Bandwidth? Differential amp Low offset. Capable of driving 50 ohm load to the scope Gain setting resistors Vishay ACAS 0612 - Precision resistor network 4x0603 resistors to make a diff amplifier with a gain of 2 Relative tolerance of 0.05% Worst case relative temp-coefficient 15ppm Project Snackey Firmware is “feature complete” Display Commands How the vending motors actually work INA219 Current Sensor Interrupts Improved method for next revision? The one byte Serial Buffer problem NEOPIXEL (WS2812) vs APA102 (SK9822) Blocking functions DMA - Direct memory access Im

MEP EP#337: CSV File WoesProject Snackey Input Firmware is completed Output Firmware is skeltonized/frameworked Need to add a “Power Good” signal Auxiliary circuits need software resets on power cycling Due to how Arduino hardware/software works The Dangers of Basing your Project on Someone Else’s ExtractModel Fortran No Github One CSV file change causes script to break Is it really broken? What to do? DIY Meat Smoker Ideas ~$1600 for the smoker body “round” part Currently 534lbs JWST sends its first official photos Incredible engineering feat Had to start with “what do we need to invent” to make this

MEP EP#336: Heirloom DocumentationUtracerV6 The right way to do instructions Full table of contents Broken out into sections. The ref designators match the section Build Test At the end is a full calibration section Section for logging your calibration values A whole section for building enclosures and wiring dos4ever.com Project Snackey PCBA completed! Smoke monster is still contained within the circuit Wrapping up the wiring inside the machine before moving onto code Installed a kiosk receipt printer where the coin return used to be and got it working Microswitches - The fidget spinner for electrical engineers? DIY Meat Smoker Ideas? Introducing the Low Poly Smoker! Nvidia could spend $10 billion to secure RTX 4000 components Hold there place in line at TSMC?

MEP EP#335: Your Toaster is ToastProject: Diff Probe Circuit Cellar design Hack a Day project Active Differential probe with 600V Common mode and 600V differential mode Measure virtually any two points. No need for ground reference. Perhaps a battery system with a boost converter? Excuse to finally use that 3d printer to make a case Basically all precision components UtracerV6 enclosure Decided to make an enclosure that better suits my use case Stripped down from last time. It does not need all the bells and whistles from last time. Fixed sockets FTDI and SMPS for 6.3V and 19.5V EOL: The Chip Shortage You Don’t See Coming Instant obsolescence No phase-out period Foundries are booked three years out Suppliers are working on their most profitable lines and filling standing orders New fabs coming online won’t be buying old wafer equipment New foundries will be making new parts Avoiding instant obsolescence What parts are more readily available and are continuity coming back into st

MEP EP#334: Double as good!Project: SNACKEY PCBs and Components arrived All PTH components fit Assembly starts tomorrow Nichicon Obsolescence Removing 8 and partial 2 of there SMT Aluminum Electrolytic lines Nichicon has 43 lines of SMT Electrolytic capacitors alone Lines they are getting rid of have these qualities: Standard range High reflow temp Low impedance New series is UBH which seems to partially cover what they are removing High Temperature Range Vibration Resistance Low temperature ESR specification Jeep A/C Troubles? Jeep AC started acting weird Vacuum leak Replaced the controller module and introduced new problems! uTracerV6 New version arriving soon 1000V @1A Check out the previous version Stephen modified on episode 135

MEP EP#333: Cody's Corner - Q2 2022Cody Endlich 10 years experience in electronic component distribution and commodities trade Currently the head of strategic sourcing at Macrofab Last seen on episode 318 to discuss Strategic Component Sourcing and MacroFab joining the ERAI What we saw in Quarter 2 2022 Russia's invasion of Ukraine Ukraine and Neon gas Neon gas is used in semiconductor production for running the lasers required for the lithography Lockdown hits Shenzhen as Covid Infections Increase Components that come out of China directly effected Raw material shortages causing ripple effects in other countries manufacturing New Earthquakes hit Japan and Taiwan Magnitude 7.3 earthquake occurred off the coast of Fukushima, Japan on the evening of March 16 Renesas and Murata operate factories close to the epicenter Took 3 days to reestablish production A Logistical Headache biggest problem for MLCC suppliers at this stage is they cannot deliver materials to Shanghai and Kunshan

MEP EP#332: This Podcast Intentionally Left BlankUSB-C will be mandatory for phones sold in the EU ‘by autumn 2024’ The rule will apply to other electronic devices including tablets, digital cameras, headphones, handheld video game consoles, and e-readers Laptops will have to comply with the rule at a later date What about laptops and devices that fall out of the 100W? USB “Extended Power Range” or EPR for 240W of power More Voltage 48V from 20V as max, still 5A Are there any USB Type-C connectors rated for the 48V yet? Stretching Stainless Stencils? PART 2 Continuation of last weeks topic Ended up being that ⅓ of the panels had poor copper registration from the PCB manufacturer Project: SNACKEY PCBs ordered from OshPark Parts ordered from Mouser Drop in Mosfets to replace TIP 102 and TIP 107? IRL510 for N-channel IXTP76P10T for P-channel Time to Say Goodbye, Floppotron 2.0 The stack of floppy drives, harddrives, and scanners is finally being put to rest after 6 years Suppos

MEP EP#331: The PCB PlagueNeutrik EtherCON Ruggedized RJ45 Lockable RJ45 cable within an XLR style housing Also come in a sealed version that offers IP65 rating Interesting PCB failures “The Plague” Black Pad Very poor to no solderability Effect of Moon Phase on Tombstoning Many factors play a role in the overall outcome of PCB assembly, especially when very small components are involved. Broadly speaking, tombstoning is a problem with very small 2-pin components (0201 caps and such) and we've filtered out the following challenges: - proper paste application - component placement - designing for "good" thermal properties of the PCB with regard to tombstoning - moon phase Stretching Stainless Stencils? Oddity Today Interesting manufacturing defect surfacing Stencil “stretches” ever couple panels or so Anyone ever seen or experienced this before? Solutions? Next Steps? Project: SNACKEY Hacking a USI/Vendnet/FSI 3159 Theory of how a snack machine works Interesting Parts UCN5890A UCN

MEP EP#330: Rogue Gerbers - Jerry McDaniel of Customer Care at MacroFabJerry McDaniel Has been at Macrofab for over 5 years Currently the Director of Customer Success Previous life, he was the CTO/CFO of Litigation Records Services A records retrieval company in Texas managing litigation records for both Plaintiff and Defense attorneys Application support for Presensoft Inc. for almost 11 years Customer Success How do you figure out how customer's act? What is the advice you can give to engineers? What is the weirdest thing a customer has ever done?

MEP EP#329: Supply Chain Crunches Reddit Question from r/ECE What are some pros and cons of becoming an electrical engineer? I'm a senior in high school, and I am giving great consideration to majoring in electrical engineering. What are some pros and cons that I should know about? From r/ElectricalEngineering - If you get an electrical engineering degree, you can get a software job. The reverse is not necessarily true. Pinotaur Supply Chain Crunches Replacing a Relay with a Mosfet Looked into Solid State Relays but nothing seems to fit Design concerns? Mosfet drivers like the IRS25752 A primer on high-side FET load switches (Part 1 of 2) Integrated or discrete load switch: which one should you use? (Part 1 of 2) Constant Innovation in Quality Control Current Sensors Replace integrated solution with more discrete solution Little differential opamp Current shunt Sprinkle in some bypass capacitors

MEP EP#328: Berry Based Physics with Collin Anderson Collin Anderson Computer scientist turned electrical engineer Has worked on things as varied as: Quantum key distribution at Los Alamos National Laboratory A tool to help decipher glyphs of the classical Mayan civilization FPGA firmware at the Ice Cube Neutrino Observatory Currently an engineer and co-founder of Orthogonal Systems An engineering and software development firm specializing in: Custom test & measurement hardware Databases Data analysis What are Particles Really? Thinking of sub atomic objects as particles muddies the water Starting with an understanding of wave theory Knowing particles are waves, the weirdness is less weird Electron Standing Waves Current flow is more like a sound pressure wave Each electron is kinda doing its own thing

MEP EP#327: Mike Kahn of Elemental Machines Mike Kahn Been working in the high tech industry for over thirty years The bulk of this time he has been involved in the architecture and design of complex electronics and embedded systems across a wide variety of segments including general purpose computing, digital communications, digital video, medical devices and life sciences instrumentation Currently the Vice President of Device Engineering at Elemental Machines, a startup that has created a service that allows LabOps professionals to monitor their lab equipment through a combination of IoT devices and a suite of cloud applications How did you get started in the industry? Elemental Machines What is it How is it all integrated Cloud Vice President of Device Engineering What is your primary focus? IoT connectivity for data gathering What is being sensed Industries served How to get started? Services for outfitting labs Manufacturing and bringing products to market for Enter

MEP EP#326: The Infinite Finite GridPART 2 : Is there a macgyver way to measure voltage without a multimeter? Lots of great suggestions in our slack channel Recreating older devices before digital multimeters where available Galvanometer Electrostatic Voltmeter Most of these require lots of experimentation or other precision devices to calibrate Let's explore the electrolysis method further Tools and measuring devices required Watch / time keeping Container of known volume Materials Distilled Water Equations from Purdue Amps & Time <-> Coulombs <-> Faradays <-> Moles of Electrons Interesting EE homework question Calculating actual component resistance by in circuit resistance measurements

MEP EP#325: Metric KnuckleKeystone Cool Part Countersunk parts? Have you used any parts like that? Design considerations Possible Assembly issues Cool 16x2 character display How do I branch into Electrical Engineering? Is it worthwhile to get certifications? Projects Finding your path. Is there a macgyver way to measure voltage without a multimeter? Electroscope - pith ball or gold leaf Vacuum may be necessary