Embedded

Roger Linn (@roger_linn) gave us new ideas about musical instruments, detailing how wonderful expressive control, 3D buttons, and keyscanning can be. Roger’s company is Roger Linn Design. We talked extensively about the LinnStrument, some about the AdrenaLinn for guitar, and only a little bit about the analog drum machine Tempest. A key matrix circuit is a popular way to handle a large number of buttons but it falls prey to n-key rollover. Roger adds force sense resistors to this (FSR example at Sparkfun). If you have an idea for an instrument, Roger has already written his response to your request for a prototype. Roger gave a keynote address at ADC '16 about the LinnStrument, including showing the sounds it can make. OHMI Trust is the one handed musical instrument society enabling music making for everyone.   Roger mentioned some other expressive instruments including: Roli Seaboard Haken Continuum Madrona Labs Soundplane Eigenharp

Phoenix Perry (@phoenixperry) returns to speak with us about education and the importance of merging art and technology. Phoenix’s website is phoenixperry.com. The art installation crossing the virtual and the physical world was called Forest Day Dream. Phoenix is teaching a free online class: Create Expressive Video Games. Phoenix is the Master’s degree coordinator for University of the Arts London Creative Computing Institute. Diversity and accessibility are important, some resources: FeministInternet.org We Are Not Users: Dialogues, Diversity, and Design Archaeologies of Touch: Interfacing with Haptics from Electricity by David Paris Critical Play: Radical Game Design by Mary Flanagan Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy by Cathy O'Neil Gone Home (Steam game) Her Story (Steam game) Bury me, my Love (Mobile game) #selfcare (Mobile game) Phoenix was previously on Embedded 204: Abuse Electricity

Chris and Elecia talk about getting transcriptions, accessibility, operating systems, and networking. Elecia recommends reading Haben by Haben Girma (@HabenGirma).  Transcripts will initially be only available to Patreon supporters. To become a Patreon supporter, go to patreon.com/embedded. If you can’t be a supporter and still really want the transcripts, hit the contact link. Chris Gammell’s nifty new podcast (video!) is Contextual Electronics.  Want to know more about how operating systems work? Listeners recommended Miro Samek’s video series.  Chris answered some questions about LISP networking. More information about the layers of the network can be found in the OSI model. The mobile focused LISP project that Chris worked on is now at openoverlayrouter.org and has pointers for more documentation and code.

Dan Zimmerman (@dmz) spoke with us about voting, voting machines, building trust in software, and transparency. Dan works for Galois (https://galois.com/ , @galois) and Free and Fair (https://freeandfair.us/, @free_and_fair). He worked on the US Vote Foundation’s E2E-VIV Project on the Future of Voting. The artifacts from that project are on github: github.com/GaloisInc/e2eviv. Dan (and Galois) worked with Microsoft on ElectionGaurd, a suite of tools to help make elections end-to-end verifiable,  The tools are open source: github.com/microsoft/electionguard The Helios verifiable online election system is also open source: github.com/benadida/helios-server We failed to talk about the DARPA SSITH and FETT programs but if you are still reading the show notes, they might be of interest. We also didn’t talk about the National Academies report on Securing the Vote.

In a surprising turn of tables, Christopher White (@stoneymonster) joins the show as a guest to talk about his career, burnout, and musical instruments.  Christopher attended Harvey Mudd College for his undergrad mathematics degree then got a Master’s degree in physics at San Jose State University. Some things he has worked on include: Multicast OSPF LISP OCT His current band is 12ax7 (12ax7.fm). The outro music is a track called “Solstice”.

Kate Temkin (@ktemkin) explained USB: how to get started, general orientation, useful tools, and when you’d use it in embedded systems. Kate’s website is ktemkin.com. She works at Great Scott Gadgets. References for USB:  USB in a Nutshell  USB Complete by Jan Axelson USB Embedded Hosts: The Developer’s Guide by Jan Axelson USB Specification, Chapter 9: USB Device Framework USB Stacks we talked about: TinyUSB from Adafruit Lufa Cortex libopencm3 For the host side: libusb Open Source VIDs are available from Openmoko and Pid.codes Kate recently gave a talk about making USB accessible. Part of the talk was about Luna, an FPGA based USB multitool. Some open source FPGA tools: Symbiflow.github.io Yosys: http://www.clifford.at/yosys/

Philana Benton (@TechnoPHILiANA) spoke with us about mentoring: how to be a good mentor, what to expect, and what not to do.  If you’d like to try mentoring, sign up for Philana’s DivTekSpace (divtekspace.org). You can do a resume review, a mock interview, give career advice, and/or refer students to your company. Philana’s home page is philanaaurelia.com We also mentioned imentor.org

Joel Sherrill (JoelSherrill) spoke with us about choosing embedded operating systems and why open source RTEMS (RTEMS_OAR) is a good choice. Embedded #307: Big While Loop: Chris and Elecia talk about when and where they’d use RTOSs Embedded #93: Delicious Gumbo: Joel gave an introduction to the RTEMS RTOS Joel works at OAR Corp (oarcorp.com) on RTEMS (rtems.org). RTEMS runs on many development boards including the BeagleBone, Raspberry Pi, and two FPGA boards: ARM ZYNQ-7000 and the Arty Board. Joel recommends the operating systems book by Alan Burns and Andy Wellens. It comes in many flavors and editions including Real Time Systems and Programming Languages: Ada 95, Real-Time Java and Real-Time C/POSIX (3rd Edition). NASA Core Flight System (https://cfs.gsfc.nasa.gov/) Experimental Physics and Industrial Control System (EPICS) (https://epics-controls.org/)

Jay Carlson (@jaydcarlson), author of The Amazing $1 Microcontroller, joined us to talk about comparing microcontrollers and determining our biases. This was an in-depth comparison of different micro features. Jay is an electrical engineer specializing in electronics design and embedded programming (contact). His blog is new and interesting. We talked to SEGGER’s Dirk Akeman about JLink on #218: Neutron Star of Dev Boards.

Matt Godbolt (@mattgodbolt) joined us to talk about assembly code, becoming a verb, 6502s, exploring compilers, and application binary interfaces. Compiler Explorer can be found at godbolt.org. The code is on github (compiler-explorer/compiler-explorer).  Matt also has jsbeeb, a BBC Micro (6502) simulator. You can try it out at bbc.godbolt.org. Its code and more information is on github (mattgodbolt/bbc-micro-emulation). Matt recently gave a video presentation about jsbeeb for ABUG.  Some other videos that may be of interest: CppCon 2016: Jason Turner “Rich Code for Tiny Computers: A Simple Commodore 64 Game in C++17” Matt’s YouTube videos on using Compiler Explorer Just enough Assembly for Compiler Explorer - Anders Schau Knatten CppCon 2017: CB Bailey “Enough x86 Assembly to Be Dangerous” CppCon 2017: Carl Cook “When a Microsecond Is an Eternity: High Performance Trading Systems in C++” The best compiler book seems to be The Dragon Book. Hyrum’s Law on writing interfaces. Application Binary Interface (ABI)