Macrofab Engineering Podcast

MEP EP#304: Cow FieldThis week Stephen and Parker where supposed to discuss bench equipment for development and testing but got distracted by talking about homebrewing beer and Maxwell's equations...

MEP EP#303: Tip Resurrection CreamBench Soldering Supplies/Consumables Solder What kind of Solder Alloy? Preferred Brands Get a datasheet! Flux core Diameter of the solder Flux Ensure compatibility of the fluxes you are using Flux cleaner Tip cleaner/tinner Brass sponge thing “Tip Resurrection Cream” Solder wick Solder pot Stephen forgot about this in last week's episode of solder equipment

MEP EP#302: A 1 Dollar Chips MatterAnnouncements Thanks for everyone that donated and stopped by the live stream! We where able to raise over $5000 for the Texas Children Hospital Network! Molex 217175-0001 Tasty Type-C connector No data pins? Only power and the CC pins for doing the Power Delivery handshake Datasheet Non FCC switcher? ICL7660CBAZA-T Super Voltage Converters Power Rail Flipper/Inverter Charge pump voltage “flipper” uses only two capacitors At an input voltage of 5V and an unloaded oscillator pin the switching frequency is 10khz Reducing to less than 9khz only takes one capacitor Price Singles: $1.82 Bulk: $1 SMT Bench Equipment for Soldering X-tronic 440 died now I need to replace! Soldering Iron Thermaltronics TMT-2000S-SM Tips S75LR018A S75DS045 Hot Air Quick 957DW+ Microscope AmScope SM series Get a 0.5x Barlow lens Tweezer set Non magnetic stainless steel is what you want ESD? Aven is a good brand Snips/flush cutters Hakko CHP-1

MEP EP#301: Crispy CurrentsAnnouncements If you are currently enrolled in college we would love to chat with you. We have some ideas for future podcast content that you could perhaps help us with. Also, we would love to get to know our listeners more. If you have not already, please send a hello email to podcast@macrofab.com. Thanks to everyone who has reached out already. On Nov 6th, Parker is doing a 24 hour video game stream for the Extra Life Charity which benefits the Texas Children Hospital network. Last year our listeners helped him raise $2600 and he is hoping to double that this year! You can donate through the Extra Life page here. Or just come hang out his personal twitch channel and chat. Will be playing from 8AM on Nov 6th till 8AM on Nov 7th. Melted fuse Holder Revisit Fuse holder on the electric fan power line melted… on the battery side *insert shock emoji* EngineerBob from Slack/twitch chat bought the same kind of fuse holders and took one apart Suspected it was not a bad crimp but the bl

MEP EP#300: Tradition is Peer Pressure From the DeadAnnouncements If you are currently enrolled in college we would love to chat with you. We have some ideas for future podcast content that you could perhaps help us with. Also, we would love to get to know our listeners more. If you have not already, please send a hello email to podcast@macrofab.com. Thanks to everyone who has reached out already. On Nov 6th, Parker is doing a 24 hour video game stream for the Extra Life Charity which benefits the Texas Children Hospital network. Last year our listeners helped him raise $2600 and he is hoping to double that this year! You can donate through the Extra Life page here. Or just come hang out his personal twitch channel and chat. Will be playing from 8AM on Nov 6th till 8AM on Nov 7th. Chris Gammell Was last on the podcast MEP EP#33: The Macro Hour Mashup MEP EP#90: Development Board Guilt Is DIY Dead? Maker Faire seems to be dead DIY projects and YouTube channels seem to be doing better then ever A

MEP EP#299: Operation Scope Creep8 Layer Design Stephen is working on a 12 pcb design 11 pcbs done 1 left 6 nets left to go out of 963 How to attack an 8 layer design? Part placement Stackup prep Multi Gauge Progress / Prop_Fan Screen and navigation CFA635-TFK-KL Temperature LTC2983 Thermistors 5V analog active sensors Level shifter TXB0104DR Shift between the 3.3V MCU and the 5V LTC2986 Power filtering Comprehensive Power Supply System Designs for Harsh Automotive Environments LT8672 LT8614 Air Quality HPMA115C0-003 PM2.5 Particle Sensor Sensirion SGP40 VOC Sensor Sensirion SHTC3 Temp and Humidity Last thing to finish on the design is to choose how to protect the inputs on the LTC2983 Demo boards only use in series 100 ohm resistors Adventures in Plastic Injection Molding Stephen got the mold state side Second round of payment due Remember Duty/tax Did the first round of prototyping - looking to validate the mold w

MEP EP#298: Has Open Source Hardware Run Its Course? Benjamin Heckendorn An electronics hacking entertainment guru Former host of Element 14’s “ The Ben Heck Show” Chris Kraft A tinkerer currently working as a software engineer in the financial services industry Extensive background in 3d printing and building anything that seems interesting Previous Podcasts with Ben and Chris MEP EP#23: Interview with Ben Heck of The Ben Heck Show MEP EP#75: Does the Simulation Match the Reality? MEP EP #153: Discrete Atomic Luffa Control MEP EP #167: BenHeck and the PinoTaur Has Open Source Hardware Run It's Course? A google search of “open hardware” or “open source hardware” yields one of two results A definition of OSHW A lot of requests for is there an open source XYZ? 10 commercially successful open source hardware projects in 2013 Top Open-Source Hardware Websites and Community in 2019 E3D’s no-nonsense approach to intellectual property

MEP EP#297: Modern College Education with Derek FronekBefore we begin this episode I have a quick announcement. If you are currently enrolled in college we would love to chat with you. We have some ideas for future podcast content that you could perhaps help us with. Also, we would love to get to know our listeners more. Please send a hello email to podcast@macrofab.com. Derek Fronek Third year EE Co-op student at Purdue University Last on the podcast episode #146 where he spoke about his time with TechHOUNDS Modern EE Education Stephen - Graduated from Texas A&M with a EE degree in 2009 128 hours required Parker - Graduated from University of Texas with a ECE degree in 2011 Derek - Will graduate in 2024 Derek's Current class load Freshman High school credits that transfer help a lot First year Engineering Purdue's way of saying “you need to do basic math and science first” General Chemistry EPICS (project based design class) Calc 1-2 Physics Mechanics/E&M CS-159 Intro to C

MEP EP#296: IdeaFab - Does This Podcast Change The World?The IdeaTank Podcast Scott Hansen and Eric Benzenhoefer are idea men who, not humbly, seek to change the world through sharing their million dollar ideas, and humbly, seek to make a podcast talking about their ideas. Previous Episodes With the IdeaTank Podcast MEP EP#77: The IdeaFab Podcast MEP EP#223: The Inverted Success Funnel – IdeaFab The Ideas Eric Benzenhoefer 5 Stars to a better tomorrow… Going to perfect feedback! Scott Hansen I am going to send you, yes you, to space Stephen Kraig The college of Above Average Joes Parker Dillmann The Otter-Matic 2000 Friendcoin

MEP EP#295: Design For EverythingThe DFs DFA - Design for Assembly DFC - Design for Conservation DFD - Design for Documentation DFM - Design for Manufacturing DFP - Design for Production DFR - Design for Repair / Recycle DFT - Design for Test DFS - Design for Safety How to DFX Identify what you are Designing For Perhaps list them based on priority Make a list of all of the items Make a timeline for which DF applies when in the product life Create a list of key design criteria This will vary based on where the product is in the design cycle Schedule specific focused time to have a team review the DF Have the main designer present, but it is best to have other perform the DF checks Have a sign off and circle back process If it passes then have the team sign off and move to the next stage If it fails, have a process of fixing and asses if another full DF meeting is needed Perhaps just a small DF meeting to address one thing At then end of the product design cycle you will

MEP EP#294: Twisted PairsUSB vs Ethernet for Test Equipment? Ethernet comes with free isolation No drivers required to get Ethernet working USB is faster to get working depending on your network hacking skills USB software stacks in test equipment are kinda hit or miss How to make hardware work with Ethernet? Still learning about this Trying out Arduino -> Ethernet shields that use the Wiznet W5100 Managed to get a demo working with SCPI and the shield Tag Connect : Edge-Connect https://www.tag-connect.com/product-category/products/edge-connect Spring loaded leaf springs in a connector that slides onto the side of a PCB Looks like a great alternative to normal tag connect Bias test connector - OTC (one time connect) PEM smtsss-4mm-6et solderable spring standoffs Use in conjunction with through hole pogo pins Just add holes and target points on main pcb and plug the connector in for access to the nets

MEP EP#293: Tom Anderson, the Gold Ear SympatheticTom Anderson An old-timer engineer working from HP/Agilent/Keysight Currently still employed at Keysight Volunteering at Alembic, where he designs electronics for bass guitars Career includes: Design of firmware Digital Analog Microwave Optical Power supplies Software Information systems Metrology and You Do I need to worry about all of this? (as a hobbyist, is accuracy important?)- Measure with micrometer... Taking Measurements voltage, current, resistance, inductance, capacitance, Q, frequency, time, noise, RF/microwave Measurement Uncertainty +/- 0.1dB specification - what can go wrong? How do you make things more accurate? System engineering - when the boards are put together, does the system work? Testing the idea that multiple resistors are tighter tolerance than single Are the values random? Sources of errors - narrow things down to the path between a sensor and an ADC Temperature Noise, thermal Noise, switc

MEP EP#292: Scott Hinson of Pecan Street Inc.Scott Hinson The Chief Technology Officer at Pecan Street Leads the Pecan Street Lab Directs research efforts to study the grid and climate impacts for integrating renewable technologies, electric vehicles, and software enabled smart devices that will modernize and decarbonize the electric and transportation sectors Pecan Street What is Pecan Street? Is it P-cawn or Pee-can? Its pa-kawn ;) How does Pecan Street go beyond the simple meters that the utility providers use Where does the data come from and how do you get access to it? Dataport Hardware device challenges Building codes Monitoring energy usage also uses energy! What are you looking forward to the most in the future?

MEP EP#291: Vaporized Copper StictionBias Test system update Happy with the two A/D Converters. Got *all* channels running Made a simple breakout board to be able to access all the pins easier 16 pin IDC cable is holding up to 450V seemingly ok - real test will be with all signals Resistor measurement was adjusted slightly Checked against 4 multimeter and getting values “in range” Next steps Finish a first version of the arduino code Merge the skipi communication with my code Solder into an actual amp to get real world values Schedule next python thing Jiva Materials “The World’s First Fully Recyclable PCB Substrate” https://www.jivamaterials.com/ PCB board that when soaked in hot water starts to delaminate Jiva is in the process of ensuring that Soluboard® is compatible with aqueous PCB fabrication processes. Jiva is also engineering Soluboard® to be resistant to high humidity environments. No technical specifications yet Circuits/metals are applied in traditional ways (plating a

MEP EP#290: Avoiding Bean CountersBGA vs. QFP - PCBA cost comparison Inspired by Tim Jager on the slack channel 48 pin QFP vs 56 pin BGA Escaping the package Layer count Increase in PCB tolerances Blind and buried vias required? Inspection costs Leaded packages like QFPs can easily be optically inspected BGAs typically require X-ray Tooling BGAs typically require small paste apertures and might require more expensive coatings and stencils Depending on lead spacing you may not need a stencil at your CM for a QFP   Using the MF platform to predict pricing Napkin math your PCB assembly cost the “easy” way Come up with a rough Bill of Materials Draw up a quick board outline that might be the size you require Enclosures dictate PCB sizes more often then not Upload to the platform Can change the bill of materials on the fly to make pricing considerations at prototype to high volume Ways to control pricing on your PCB Assembly

MEP EP#289: Snicker Bar Integrated ComponentsMinor correction from last week. IEC 60950-1 was withdrawn in December of 2020, and has been replaced by IEC 62368-1 (Product Safety testing standard for “Information Technology Equipment” and Audio Video Equipment) Defcon 29 How was it? Attendance Favorite thing Badge Results? Reception Talks TI soic oddities? TL072 Large indicator mark Laser marking has the TI logo but the line goes through the dimple Very offset marking Sharp cut body? Tasty Chips https://www.tastychips.nl/ SSI2140 Based on the original core of the SSM2040 (Solid State Micro Technology for Music ) Voltage Controlled Multi-Mode Filter Four variable transconductance cells with i-v buffers Q-compensation Temperature compensated http://www.soundsemiconductor.com/ Interesting reverse engineering tactics? In regards to customer projects? How often do you have to reverse engineer products or designs?

MEP EP#288: We have clearance, ClarencePCB design rules for clearances Stephen's favorite calculator Clearance and creepage According to the IEC (international electrotechnical commission) a global standards organization Clearance - The shortest path between two conductive parts, or between a conductive part and the bounding surface of the equipment, measured through air Creepage - The shortest path between two conductive parts, or between a conductive part and the bounding surface of the equipment, measured along the surface of the insulation IEC/UL 60950-1 Safety standards - has more in depth information on spacing and how to handle mains IPC2221 generic pcb design rules - Has simple information on spacing vs voltage The creepage requirements depend on insulation material group Comparative Tracking Index (CTI) is used to measure the electrical breakdown (tracking) properties of an insulating material. Tracking is an electrical breakdown on the surface of an insulating material wherein

MEP EP#287: Biased For ArduinoBias Test System Got the first board built and installed on an arduino First tests were a success Arduino library - works “first” time Adien Akhmad 2.5V reference voltage MCP1501T-25E/CHY 0.1% initial accuracy 50ppm drift I have measured a handful of these at work and have found the output to be within this range - 2.498 Arduinos and USB are noisy Resistive measurements via constant current Opamp driven constant current source 1mA output current measured @ 1.001mA with a 1k resistor Output current is somewhat load dependent - higher at higher resistance values Possibly should have gone with a parallel opamp config Validation Voltages seem to be reading well. 0 to 300V was within 1% of meter Small “offset” reading This is due to input buffer amp offset. Datasheet calls out 125 as typical and 750 as max I have seen the 100 to 400uV range Will calibrate out When doing a simple offset correction I can get 0.00000X readings For resistive

MEP EP#286: FTC “Nixing The Fix” ReportFTC “Nixing The Fix” Report The debate around repair restrictions illustrates the limitations of MMWA’s anti-tying provision in repair markets. While the anti-tying provision gives consumers the right to make repairs on their own or through an independent repair shop without voiding a product’s warranty, repair restrictions have made it difficult for consumers to exercise this right. Although manufacturers have offered numerous explanations for their repair restrictions, the majority are not supported by the record. How manufacturers may limit repairs by consumers and repair shops, and how those limitations may increase costs, limit choice, and impact consumers’ rights under the Magnuson-Moss Warranty Act The statute is remedial and is intended to protect consumers from deceptive warranty practices Consumer products are not required to have warranties, but if one is given, it must comply with the Magnuson-Moss Act. Defines definitions and disclosure standards Bars

MEP EP#285: Let The Robots Do It Finally real engineering… follow up What is the most computational intensive work you have had to do on the job? Mixed Integer Non Linear Optimization problem Apopt solver Pyomo SK -2d polynomial matrix...thing Email from a listener! Our “assessment that it is uncommon for engineers to need this is quite biased since both of you work in manufacturing” Clarification of point Most of Stephen's time has been split manufacturing and design Theory classes do reinforce your “gut check” and “rules of thumbs” Python SCPI Test Development Recap of Saturday Stephen’s Bias Test Board Issue with devices resetting/losing communication Bias test board Finding the right A/D kind of sucks It is never just resolution Lots of variables to juggle Resolution Speed Cost Accuracy Package Features Not so features PGA Digital filtering Caddock 1776-C681 resistive divider 0.05% tolerance Convenient 1/n division 0 to 1000V down to 0 to