Circuit Break - A MacroFab Podcast

• Cliff Schecht
  • An electrical engineer with a masters degree
  • Spends his days rescuing vintage gear
  • Is the CEO and operates Reclaimed Audio
  • Reclaimed Audio offers repair and restoration services on audio, radio, and test equipment from the turn of the century through current state of the art
• Restoring Vintage Audio Equipment
  • How to restore equipment and keep it true to original design, but get it ready for another 20 years run time
  • Rebuilding power supplies on tube units for example, but not changing the audio path topology much
  • Tips and tricks with test gear
  • Properly evaluating a piece of unknown gear
  • How to restore vintage electronics
    • How old is old enough to consider restoration/recapping
    • When is it ok to power up? How do you power up vintage gear?
  • Any myths you have debunked?

Tags:  Audio Repair, Capacitors, Cliff Schecht, electronics podcast, MacroFab, macrofab engineering podcast, Reclaimed Audio

• 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
• Past two years
  • Both where last seen on Episode 75: Does the simulation match reality?
  • Ben has moved on from hosting "The Ben Heck Show"
  • Chris has been experimenting with SLA resin printers
• Hangprinter
  • A very simplified explanation is you take a delta printer but instead of having the three motors that are attached to the side frame you instead locate those motors wherever and have wires/cables/etc that run up to points that you mount
  • Some videos that show how it works
    • Hangprinter Presentation
    • Thomas Sanladerer interviews The Hangprinter
    • Building the Hangprinter: The Basics!
  • The first new/interesting thing Chris has seen in awhile
  • Project is open source so people are free to contribute and find ways to improve the design
  • One thing I feel is potentially a missed opportunity is the focus is on making it cheap
• ODrive
  • Designed to give motor control to hobby grade brushless DC motors instead of stepper motors
  • Hackaday.io project
• New Makerbot printer named "Method"
  • Non-heated bed is a “feature”?
  • Latest design seems to prefer technologies that Stratesys can or already has patented
• Consider the humble Luffa
  • For a long time manufacturing has mostly used subtractive techniques
  • Until recently most manufacturing was about taking raw materials and cutting, bending, etc into the desired pattern
  • Look at that infill
  • Additive manufacturing is really different when you think about the possibilities
  • What if we could use CRISPR to "reprogram" plants to produce other things? Like growing a replacement organs, body parts or something else completely?

Tags: BenHeck, Benjamin Heckendorn, Chris Kraft, electronics podcast, Hangprinter, Luffa, MacroFab, macrofabe ngineering podcast, Makerbot Method, ODrive, SLA Resin Pritners

• Josh Rozier
  • By day Josh Rozier does business intelligence and data analytics for a large, east-coast insurance monolith
  • By night he is Roz, a level 5 Scoundrel and chief troublemaker of the StarWars D20 RPG group
• Is the Force a Force?
• Hyperspace Ramming
• 12 Parsecs? Solo’s famous line that shows Lucas has no idea what he was writing.
• Predictions from the previous podcast
  • Stephen was right - Luke Died
  • Parker was wrong. Though is Rey really a Jedi without training?
  • Rey didn’t change her name to Neo
• Predictions for EP9?
  • Is luke actually dead?
  • Will we see CGI Carrie Fisher?
• Best and Worst movies of the Star Wars Franchise.

Tags: Boson, electronics podcast, HyperDrive, Kessel Run, MacroFab, macrofab engineering podcast, Midichlorians, Parsecs, StarWars, Vader

• Brandon Satrom
  • Developer Advocate for Particle, an IoT platform company
  • The founder of Carrot Pants Press, a company dedicated to educating makers
  • On the MacroFab Engineering Podcast Episode Number 122, Brandon discussed the Particle Photon and built an IoT breathalyzer with Parker live on the podcast
• What is currently distracting Brandon now?
  • Why mesh networking matters
  • Existing mesh networking standards
  • Thread/OpenThread and why Particle built OpenThread into 3rd gen devices
    • What is OpenThread?
  • Mesh Christmas Tree project
    • 5 device network with a gateway and 4 edge devices
    • Particle Blog detailing more about the project
    • One edge device publishes multicast messages to all other nodes, which light up neopixel strips when those messages are received on each device
    • The goal was to see how low latency UDP-based mesh messaging was
    • Researching theory around "the color of sound" and added a mode to the firmware that converts the frequency of a played note into a corresponding rgb value on the color spectrum. Kinda.
      • Synethesia
    • Working today on a mode that ties the Adafruit Neotrellis into the network to create a "tree synth"
• Questions from Jarret from our Public Slack Channel
  • Could you have a sportsgame of some sort, and hand out each spectator a little LED/LCD with mesh chip, and have all 10k systems attempting to figure out where they are in the stadium, and maybe also connect to a base station, so they all receive color information and turns the audience into a huge display?
    • Reminds Parker of the North Korean "displays"
  • What is a good distributed power system for mesh networking?
  • I've started logging metrics for my indoor garden, but currently I'm using a million phone chargers plugged in everywhere and that kinda sucks
• Update on the Carrot Pants Press?
  • Lastest kickstarter was a success!

Tags: Carrot Pants Press, IoT, Mesh Networking, OpenThread, Particle, Synethesia

Congratulations to our Slack member Mobius Striptease! Mobius’ pulse generator won first place at their Senior Design Expo!

Article written about MacroFab: Houston electronics manufacturing company gears up for growth. Talks about the growth of MacroFab over the past 2 years.

• Parker
  • RPI3 Compute Module
    • PCM5122 Routed
    • LAN9514 Routed
      • single upstream USB port on BCM2835
      • Pin 44 Ethernet 25MHz output
      • Pin 31 LAN RESET
      • Information found on the Raspberry pi forum
    • Need to add USB current limiting
    • CM3 HOME
      • Guido Ottaviani made his own carrier board I have been looking at for inspiration to solve some of the final problems
    • 1473149-4
      • Connector being used to socket the RPI3 Compute Module
• Stephen
  • Crazy EQ amplifier design continuation
    • Opted to go with a card edge solution for each EQ band
    • Each band connects via a 36 pin PCI-Express connector
      • +12V
      • -12V
      • +5v Reference
      • -5V reference
      • Gnd
      • 4 In Signals
      • Cut
      • Boost
      • Potentiometer pin 2
    • 21 modules in total. 1 module has all of the power and main signal in/out from the amp. This sends all of the other modules their power/ground and signals.
    • Need to rethink things - Feedback loops are crappy.. Need to go with a 64 pin solution
      • 20 ins and 20 outs
  • Beveled edges and Hard Gold plating discussion in a future episode
• R.F.O.
  • Debugging I²C with Hardware
    • I²CDriver is a crowdfunded effort by James Bowman
    • Open Source tool used to easily drive I2C devices
    • Controls with a GUI, command-line, C and C++ using a single source file, or Python 2 and 3, using a module
  • Low Cost Reverse Polarity and Over Current Protection
    • Jeri Ellsworth's new video on reverse bias protection
    • Has a Robbie Robot on her desk!
    • Methods
      • “One of the options is to do nothing”
      • Diode input
      • Exploding Diode
      • PMOS FET
        • Low rds on - “almost not there”
        • Body Diode - Watch out for this

Tags: 1473149-4, 20-Band, CM3 Home, electronics podcast, EQ, i2c, Jeri Ellsworth, LAN9514, MacroFab, macrofab engineering podcast, Mobius Striptease, PCM5122, Reverse Polarity, Reverse Polarity Protection

• Matt Glazer
  • Lead electrical engineer at KINETIC
  • Building IoT wearables for the industrial workforce by day and building electric long-boards by night
  • Obsessed with space and can talk hours on end about the current state of space technology
• Jeff Doong
  • Head of manufacturing at KINETIC
  • In charge of making sure current products are manufactured correctly and new products are designed to efficiently scale
  • If he wasn't at KINETIC, he'd be a farmer back home in California
• KINETIC
  • What is KINETIC?
    • Last time we had KINETIC on the podcast it was episode #53 with Aditya and Mijael. What has changed since February 2017?
    • Product has a name now. Now longer called the device.
  • Expand a bit more on what you two do at KINETIC?
  • Any major engineering challenges yall had to overcome since the last prototype?
  • KINETIC has been expanding to scale up manufacturing. What were some of the engineering changes needed to do so?
  • Supply Chain management?
  • Case Study on the MacroFab website

Tags: electronics podcast, Industrail, IoT Wearable, Jeff Doong, Kinetic, MacroFab, macrofab engineering podcast, Matt Glazer, MEP, Scaling Manufacturing, Supply Chain Management

The podcast got mentioned in an article! 12 Great Podcasts for Engineers from the Mind Tribe blog. Mind Tribe is a design driven engineering firm based in San Francisco. The list spawns from a survey from the engineering team at Mind Tribe. Thanks Mind Tribe for mentioning our podcast!

• Parker
  • RPI3 Compute Module
    • Added PCM5122
    • Added LAN9514
      • Still figuring out the schematic part
      • Ethernet and USB hub built in
  • EFM8 Universal Beeeeeeeeeee
    • Com port native! VCP driver
    • Secret Project
      • It may DOOM everything
    • ST7735
      • Common SPI TFT Screen Module
      • 1.44” 128x128 pixels
  • Wagon Update: YouTube videos
• Stephen
  • “Feature creeped” my way into designing a 20 band graphic eq and a fancy solid state effects loop
    • 20 band eq with +/- 12ish (simulation shows 13.8) db of gain per band
    • Each band has a Q of 2.87 so they end up being ½ octave
    • Using the 1kHz standard
    • Designed with “constant Q” in mind
• R.F.O.
  • STM releases STM32 Cube MX V5.0
    • Redone UI and cleaner look
    • Better searching options
    • Looks like a more streamlined approach to configuring your uC. Sort of a “left to right” path
  • CNC Router options?
    • Need a 2’ x 4’ CNC machine
      • CNC Router Parts
        • CRP4824 router kit
      • Vacuum Table
      • Get a Guest for DIY CNC
  • Cheeseburger Compass
    • GPS and Raspberry Pi combined to let you know where the nearest Cheeseburger fast food place is.

Tags: 1kHz Standard, 20 Band EQ, Cheeseburger Compass, CNC Router, Compute Module, Constant Q, CRP4824, Cube MX, DOOM EVERYTHING, EFM8, electronics podcast, LAN9514, MacroFab, macrofab engineering podcast, MEP, Mind Tribe, PCM5122, Raspberry Pi, RPI CM, ST7735, STM32, Universal Bee, VCP Driver

• Charlyn Gonda
  • Coder by day, maker by night
  • A chronic problem solver and is currently in the middle of her year-long project, 12 Months of Makes
  • Has too much fun building circuits, creating things with 3D printing, crafting hats and coding IoT devices!
• Topics
  • Charlyn what is your background? Day Job ect?
  • Why did you become a Software Developer?
  • How did you go from a Software Developer to building Hardware for the first time?
    • Any particular reason you wanted to start building hardware?
  • How do you approach hardware design? Is it in anyway the same as software development or radically different?
  • What is the 12 Months of Makes
    • Projects you have completed so far?
      • Bongocat
      • Sharknicorn
    • Almost at the end of the 12 Months of Makes. How successful was the experiment?
  • Words of wisdom to other software developers that are thinking about hardware creation?

Tags: 12 Months of Makes, Bongo Cat, Charlyn Gonda, Eats, electronics podcast, IoT, MacroFab, macrofab engineering podcast, MEP, Particle, Sharknicorn, Uber

• John Waidner
  • Electronics Engineer with a background in Logic design, analog circuit, system integration and testing
  • Currently John is a mentor for the TechHOUNDS and volunteers for the Boy Scouts of America
• Derek Fronek 
  • High school student from Carmel High School
  • Part of the Carmel High School robotics team the TechHOUNDS
• TechHOUNDS
  • What are the TechHOUNDS and how did you start?
  • Leadership? Who leads the group?
  • Divisions
    • Robot Ops
    • Programming/Electrical
    • Construction
    • Information Technology
    • Public Relations
  • How do you handle the overlap between divisions?
  • Derek - What division are you most involved with?
  • John - How involved are you in the process?
  • What is FIRST (For Inspiration and Recognition of Science and Technology)
    • Who can be a part of FIRST?
    • How to get involved
    • Funding?
  • Competing in FRC (First Robotics Competition)
    • What are the competitions?
    • How does your team prepare for them?
    • Who gets to go?
    • Who gets to drive the bot?
  • The TechHOUNDS youtube channel has lots of videos of the robot and competitions the group has been in
    • 2018 Robot Reveal
    • TechHOUNDS Team 868 Flickr
  • What is next for the TechHOUNDS?

Tags: Derek Fronek, electronics podcast, FIRST, First Robotics Competition, For Inspiration and Recognition of Science and Technology, FRC, John Waidner, MacroFab, macrofab engineering podcast, MEP, Robotics, TechHOUNDS

• Stephen's Vox in a Box
  • Preamp Design
    • Vox AC30 preamp - 3 gain stages with a cathode follower and a phase inverter
    • Phase inverter - create differential signals for the power amp input
    • Drop signal using voltage dividers and mosfet buffers
    • 320V phase inverter to 18V buffer drive
    • Built point to point on an aluminum plate for easy modification and testing
  • Power Amp Design
    • TPA3116 Class D amplifier
    • LM311 comparator mute circuit for start up mute ~5 to 10 Seconds
    • Runs at 400KHz - Left open pads for boosting this up to 1.2MHz
      • Is there an advantage at running at higher frequencies?
  • Power Supply Design
    • TPS40210 Switching controller into a diode/cap ladder voltage multiplier
    • 7 stages of multiplication leads to ~50V per stage
    • Variable Switching from 35KHz to 1000KHz
    • PMP8621 Appnote
  • Testing the Vox in a Box
    • Been going nonstop for weeks now
    • Have taken it up to nearly 60 Watts without problems
  • Layout of the PCB
    • Multiple ground system with master start
    • Each sub circuit has its own ground return
    • 8 Master star ground returns
    • 4 layers
  • Issues with the current design
    • High Voltage SMPS does not like high capacitive load
    • Ground for signal input is very important - Nearly all noise is dominated by this single point
      • Alligator clips for signal patching are not low noise…
    • Cold Heater impedance
  • Current Schematic for the Vox in a Box
  • Fusion 360
    • New amp design
      • Learning by building a virtual amp
    • Vox in a box
      • Going to model the whole design to ensure proper fit
• R.F.O.
  • Improve your circuit toolbox – Simple designs that will save your next product
    • Chris Gammel gave a talk at the recent SuperCon about circuits you should add to your mental filing cabinet
    • Speaking of the Super Con all the videos for the talks are live on Youtube so go give those a listen to!

Tags: Chris Gammel, electronics podcast, Fusion 360, Hackaday, LM311, MacroFab, macrofab engineering podcast, MEP, PMP8621, Preamp, SuperCon, TPA3116, TPS40210, Vox AC30, Vox in a Box