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

Podcast

148

Parker Dillmann | November 28, 2018

MEP EP #148: A Unique Perspective on Feature Creeping

Podcast Notes

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!

“This is a technical podcast by a Texas-based PCB fab and assembly house where the two hosts (Parker and Stephen) have conversations about electrical engineering. Parker and Stephen provide a unique perspective on hardware and the show is both entertaining and educational.”

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” 128×128 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
  - W taper pots and ways to convert that
  - Both the FX loop and the EQ interface with 200v input signals
  - Applied a 1:50 reduction to get within a reasonable range.
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
  - What is your path? Pins first? Clock First? Communication? Timers? Interrupts?
- CNC Router options?
  - Need a 2’ x 4’ CNC machine
    - CNC Router Parts
      - CRP4824 router kit
    - Vacuum Table
    - Get a Guest for DIY CNC
      - Picking out lead screws
      - Motor specifications: Stepper Vs Servo
      - Controllers
- Cheeseburger Compass
  - GPS and Raspberry Pi combined to let you know where the nearest Cheeseburger fast food place is.

Visit our Slack Channel and join the conversation in between episodes and please review us, wherever you listen (PodcastAddict, iTunes). It helps this show stay visible and helps new listeners find us.

Parker has lots of routing work left on the RPI Compute Module board.

Diagram of the potential PCB stack up for Stephen’s EQ design.

Special thanks to whixr over at Tymkrs for the intro and outro!

About The Hosts

Parker Dillmann is MacroFab's Co-Founder, and Lead ECE with backgrounds in Embedded System Design, and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. He also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components. Parker graduated with a BS in Electrical and Computer Engineering from the University of Texas.

Stephen Kraig began his electronics career by building musical oriented circuits in 2003. Stephen is an avid guitar player and, in his down time, manufactures audio electronics including guitar amplifiers, pedals, and pro audio gear. Stephen graduated with a BS in Electrical Engineering from Texas A&M University.