MEP EP#355: The One They Talk About Football Fields For a Long Time
End of 2022 Engineering Questions?What trends in the past few years have changed PCBAs the most in the last few years? Weird SMT packages are starting to become more normal PCBs themselves are being used more as a structural part of the overall product What do you think will be the next “big” thing that will change the way EEs design PCBs? Rigid Flex changed the way compact consumer devices where designed Advancements in mosfet technologies and materials increased power densities
PDMListener Questions During the project do you plan on hosting it so it’s accessible somewhere like GitHub? Why plan for peak currents on constant current rating on the pins? What are the plans for customer connections?
StarWars Christmas Special will be December 13thReturning Cast! Roz, Chris Kraft, and HyR0n!
MEP EP#354: A Consumable For Your Wallet
Louis Rossmann’s fresh start in Austin, TxMoved his business from New York to Austin, Texas Learn how to open and fix things Classes will be free
Mercedes Makes Better Performance a $1,200 Subscription in Its EVsSubscription to make your car vroom vroom faster Acceleration from 0-60 mph is said to improve by 0.8-1.0 seconds and the overall characteristics of the electric motors are supposed to change as well
Microjet Spray SystemStarted 3d modeling the idea Amazon link Venturi Mist system with separate air and alcohol controls Multiple ball joint nozzles that are individually adjustable
StarWars Christmas SpecialDecember 13th?
MEP EP#353: The Name Will Arrive
Jeep Prop Fan ThingyJeep Prop Fan thingy Spec Sheet Connectors The Quest for 25 Amps TE Connectivity 1-1418362-3 Pg 63 of this catalog Haltech released a new PDM 10 8A 4 25A 2 Push Pull
Arduino OptaArduino's First Micro PLC supporting standard languages including LD (Ladder Logic Diagram) and FBD (Function Block Diagram) STMicro STM32H747XI dual-core microcontroller Opta Lite, Opta RS485, Opta WiFi High-power relay switching (4 x 2.3 kW)
ManimEpisode 340 Necrobiotic Synthesizers Finally got it installed and playing Looking into circuit animation
MEP EP#352: CNC Crafting
November 5, 2022 - Extra Life RecapImprovements to the script Thank you to everyone that hung out, supported, and donated!
What is next for CNCParametric cnc model in fusion Model by Ed Frazier https://grabcad.com/library/parametric-cnc-router-1 Changed to a 5x5 cutting surface All 8020 construction with good bit of milled aluminum Added a 40 series table ATP-5 aluminum by vista metals https://www.vistametals.com/assets/pdfs/products/atp-5-precision-tooling-plate.pdf Precision tooling plate Cast aluminum 5000 series Can be welded and about 5% lighter Excellent corrosion resistance RMS value of 15 to 20 Thickness tolerance of +/-0.005 Good flatness tolerance Building up Z axis after the pod Next steps: Finish drilling and tapping all the holes Buff all of the surfaces with scotch brite wheels Anodize
MEP EP#351: Signal Switching for Maximum Offness
Python Demo for Extra Life APIStream Date: November 5th, 2022 Python to OBS functioning! Websockets. What are they? HTTP is unidirectional where the client sends the request and the server sends the response Websocket data is continuously pushed/transmitted into the same connection OBS has a built in local server that you can establish a websocket with another application Python module obswebsocket Provides a wrapper for all the OBS websocket functions Can basically control anything in OBS it seems Documentation is a bit lacking and module is out of date Build animations and transitions in OBS and modify them with the python connection Building a donation progress tracker?
Signal switching tipsManeuvering signals around your design Methods of switching on and off portions of your circuit Series Shunt Series-shunt Relays DG series of analog switches Virtually every configuration single, dual, quad SPSTs and SPDTs, 4:1 and 8:1 multiplexers Many have separate control and signal voltage inputs
Estimating project timeFollow up from slack Josh Pieper - Doomcheck Takes in a text file and uses probability distribution to estimate timing for projects
MEP EP#350: Estimating Effort
Python Demo for Extra Life APIStream Date: November 5th, 2022 Functionality so far Check Extralife API for donations This is done with the requests module This endpoint seems to return old and new donations There isn't a “new donation” end point it seems Get the donation IDs and compare them to a local file Local file is made with the pickle module Pickle allows you to take any data structure in python and “package it” into a binary file for storage. If there is a new donation ID that isn’t in the local file Queue up a random audio clip Record the donation ID to the local file Audio is placed through the playsound module Weird “bug” that short audio clips get cut off Add a little sleep after the call to get around it Auto parses the audio folder for the files Looks into audio file Gets all the file names Adding a new audio clip is as simple as dropping it into the folder Preventing truly random files Made a rotating buffer Used the collections module to implement a bi-directional “stack” Think like a bitwise shift but with an array of strings Multithreading! Threading module used to setup the API and Audio player queues API runs every 20 seconds Audio player runs every 30 seconds If a new donation, global mailbox variable increases one for each new donation. Audio player runs and looks at that global variable. Threading has a “lock” function to prevent race conditions on that global variable. What is next? Play graphics in Open Broadcast Software OBS has some python hooks that I am just starting to learn
Chip Fab JobsNeed practically every engineering discipline Mechanical to design and maintain equipment Chemical for designing the masking / chemical bath processes Electrical for testing and validation
Estimating project timePCB layout New project revision About 1600 parts Lots of duplicates Things that impact timing Components Parts with pours and complex ground Specific trace routs like differential or snake traces Layers Duplication Rest day Cleanup day
MEP EP#349: Connector Catalogs
November 5, 2022 - Extra LifeHaven't had a chance to work on this yet Going to stream working on it?
Adventures in injection moldingPINNACLE 5112C3 8% haze - this is pretty low. Any lower and it would be considered “clear” Low melt flow, excellent processability - Voids Two ways to create diffusion Haze Surface Texture
Jeep Prop FanHalf bridges for each output Current sensing INA219 Inputs Found a product that will do the thermocouples on canbus Instead of that crazy LTC2986 chip Just expose an ADC 0-5V Connectors are the hardest part of this project so far Dictate the entire specifications
RFAB2 Lab - an expansion of the RFAB1 LabSept. 29, TI announcedt began initial chip production at RFAB2, a new 300-mm analog wafer lab in Richardson, TX 300 analog fab digital isolator Ethernet transceiver brushless DC motor driver digital-to-analog converter 100M units/day within a few years
MEP EP#348: AVRDUDE All The Way Down
November 5, 2022 - Extra LifeContent for the stream API for Extralife Custom plugin that goes to a Duke Nukem Sound Board Trying to get it to play gifs Working with Open Broadcast Software now
Live podcast Nov 22 in Houston
Microchip woes?Microchip has got back to us about the firmware - no issues on their end Suggested using the command line interface Originally thought pullups on the reset line but they are not needed Tried them with no luck
Jeep Prop FanRecently talked about designing a PCM (Power Control Module) Essentially control all the none engine related functions in a car Need a new name since it's not for the Jeep nor uses the Parallax Propeller Raspberry pi pico Do we do Arduino style C or Micro Python? Micro Python will be cool to try out! PIO will be used for controlling reactionary lights Turn signals Headlights Solid State Relays are EXPENSIVE Mosfets for sure H-Bridge for bi-directional motors Combine with OCTOPROBER?
MEP EP#347: Out Of Bounds Engineering
November 5, 2022 - Extra LifeI play games for children's hospitals Raised $5,169.42 last year Was the number one raiser for the Texas Children's Hospital What game for this year? What should I make for the stream? API for Extralife Duke Nukem Forever and Aliens Colonial Marines Custom Stream plugin for the games
Live podcast Nov 22 in Houston
Hacking FR4 for light transmissionUsing FR4 as a light diffuser Things to consider FR4 material Yellow Blue Green Gray Distance LED Angle LED brightness Light Bleed Pipes Dividers
PCB Ruler ReduxJames Pleger from slack channel
“Credit card” style Different stackups of material
MEP EP#346: Calibrating CNCs with PCB Rulers
November 5, 2022 - Extra LifeI play games for children's hospitals Raised $5,169.42 last year Was the number one raiser for the Texas Children's Hospital What game for this year?
CNCCalibration 90 Dust Collection 2/4/5/6 in pipe Thinking I will do an overhead PVC solution Have to design a skirt capable of interfacing with a 4 in hose
Battleship TexasGoing to try to get someone on to talk about the restoration
PCB Ruler ReduxWhat do people want to see on them? What makes it actually useful?
Live podcast Nov 22 in Houston?
MEP EP#345: The Hot List of Tasty Chip Fabs
Pool Shark Update!
Wolfspeed fab for NC is latest on CHIPS Act list668,000 domestic manufacturing jobs Global Unemployment. Do we have enough people for this? What technology are they aiming for?
Here’s the latest hot list of cool chip fabs coming to the USGlobalFoundries 180nm down to 12nm Intel Ohio New Mexico Arizona Micron Memory Chips Samsung High end computing Texas Instruments 45nm+ analog, embedded electronics Articles say it will complement other factories already in Texas TSMC 5nm Wolfspeed Worlds largest silicon carbide manufacturing facility Much higher power devices with higher voltage capabilities due to large band gap
Failure Friday - Break something at the office this week? We want to hear about it!Billed the wrong phase of a project Dry air means static buildup, I don't think my 3v test circuit appreciated being a path to ground :'-( I ran over a 3D printer with a forklift Saw a customer supplied "napkin sketch" that stated 12'x12" (12 feet x 12 inches). "I read it as 12 inches x 12 inches, product was cut to that size." Customer was not happy Sparky sparky boom boom
What to do to make your open source project more accessible - or more popularUse popular tool chains and environments for ease of access If the tool chain is not simple to install, offer a docker or really good instructions Document your process and have someone test your instructions! Cherish all feedback If someone has a problem, do not say "works for me" They may have found an edge case to fix!
MEP EP#344: Fierce Key Inventory
Differential probe design updateTrying 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 / CanisterTurned out great so far will have to see how it holds up under the heat Pictures on the blog
Digikey NewsletterCheck 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 Bad
Bricking Microcontroller - Watch those fusesPic, AVR, STM Atmel ATXMEGA16A4U AVR studio and microchip studio AVRDUDE
Air Filter / CanisterLong 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 Experts
HyR0nMathematician Computer Scientist AND!XOR employee of the month Working on badges and things Hackery
Previous Podcast EpisodesIncognito 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 BadgeIts 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 micropython implementation was done for firmware Always interested in python We always lived in a C world Makes hacking it easier for end user Micropython vs Circuit Python The Hacking Challenge - BENDER Flashing Party - Things you should think about - i.e. Design for Drunk Hacker Production You’re going to do the same thing thousands of times, what do we automate? Loop script for provisioning Push bare minimum over serial, then use wifi to complete Turning screen green once flash done and charge at 100% Other thoughts? Really different than what we do, was really fun People like bling more than function, but …
MEP EP#341: Project Snackey Recap
Project Snackey at Defcon30What 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 Synthesizers
Project SnackeySee y'all at defcon 30!
Stuff you want to learn about?Canbus FPGA design AWS web development Manim - python
My Spider-sense is TinglingSpiders are just hydraulic animals
MEP EP#339: Educated Compromises
Project SnackeyAnnouncement video lands before this podcast gets released.
Project DiffprobeLooking 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 Products
Project DiffProbeLanded 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 SnackeyFirmware 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 Importance of full system integration testing Timer Lockouts for motors Is there a better way?
MEP EP#337: CSV File Woes
Project SnackeyInput 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’sExtractModel 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 photosIncredible engineering feat Had to start with “what do we need to invent” to make this
MEP EP#336: Heirloom Documentation
UtracerV6The 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 SnackeyPCBA 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 componentsHold there place in line at TSMC?