Embedded

Chris and Elecia take an in-studio vacation, chatting about what they've been doing. A few technical topics came up, entirely unintentionally. Shirts are on sale James Webb Space Telescope Pop-Up Card Spicy Honey Github Codespaces lets you try out some code bases Some quirks of C How do breakpoints even work? (via Memfault's Interrupt) Transcript

Thea Flowers creates open source and open hardware craft synthesizers that use Circuit Python for customization. She also writes about the internals of the SAMD21. Thea's synthesizer modules are found at Winterbloom, including Castor & Pollux and the Big Honking Button. It is all open source hardware so you can find code and schematics on Thea's github site: github.com/theacodes Thea's site is thea.codes. You can find her blog there with deeply technical and detailed posts such as The most thoroughly commented linker script (probably), The Design of the Roland Juno oscillators, and Understanding the SAMD21 Clocks. She's on Twitter as Stargirl, @theavalkyrie. For more information about the Eurorack, listen to Embedded 356: Deceive and Manipulate You with Leonardo Laguna Ruiz of Vult.

Sarah Withee spoke with us about using an artificial pancreas, learning many programming languages, and FIRST robotics. More about the Open Artificial Pancreas System can be found at OpenAPS.org or in their documentation. Some other pieces we talked about include: LoopKit: an automated insulin delivery app template for iOS github (some additional docs) AndroidAPS github (additional docs) Reilly Link is the communication method for some insulin pumps Orange Link is a Reilly Link compatible device to run OpenAPS To get involved with FIRST robotics, the place to start is FIRSTInspires.org Sarah's website is GeekyGirlSarah.com. Her programming language comparison tool is Code Thesaurus: codethesaur.us/ If you want to see small algorithms written in different languages, check out Rosetta Code Transcript

Michael Gielda spoke with us about Renode, an open source embedded systems simulator. It also simulates large distributed systems and network communications. Check out Renode.io and the boards supported by Renode and Zephyr on Renodepedia. Elecia played with the Nucleo F401 tutorial on colab. Michael is the co-founder of Antmicro. The ESP32-C3 is a commercial RISC-V core with WiFi and BLE. We also mentioned Wokwi on the show. (And we had its creator Uri Shaked as a guest on episode 396: Untangle the Mess Transcript

Martha Wells is a science fiction and fantasy author. She spoke with us about her books (including Murderbot Diaries!), writing, and creating fantastical worlds. Marth (@marthawells1) has won Nebula, Hugo, and Locus Awards for her work. We mostly talked about the Murderbot Diaries and the Books of the Raksura. Oh, and the Star Wars tie-in about Leia, Razor's Edge. And The Witch King is coming out next year, a brand new world. Heck, just look at her full catalog. Martha also has a blog and a website. As often happens when book dragons get together, we talked about our hoards. Some books and authors that came up: Red Scholar's Wake by Aliette de Bodard The Spare Man by Mary Robinette Kowal Ian Halle Ancillary Justice trilogy by Ann Leckie Phyllis Gotlieb (Wikipedia) Andre Norton (Wikipedia) Zenna Henderson (Wikipedia) The Vorkosigan Saga by Lois McMaster Bujold (we didn't like the new covers as much as the old but the books are great either way) Tor.com is a fantastic site with lots of free fiction. Murderbot started there and has a few short stories that are otherwise hard to find. There is a rare and sold out Subterranean Press edition of the Murderbot Diaries with illustrations from Tommy Arnold. See some of the illustrations. Transcript

Jasper van Woudenberg spoke with us about hacking hardware, writing a technical book, and ethics. The Hardware Hacking Handbook was written by Jasper and Colin O'Flynn (ChipWhisperer and episode 286: Twenty Cans of Gas). The site related to the book is hardwarehacking.io, you don't need the book to play with some of the examples. Jasper (@jzvw) is also the CTO of Riscure North America, a company that specializes in hardware security. They are hiring. Transcript

Chris and Elecia bounce from topic to topic, discussing life and work and occasionally answering listener emails. Python can format code into equations in Latex with Latexify (as noted in this tweet) Interesting sensor: Sensing deep-tissue physiology via wearable ultrasonic phased arrays Turing Complete - a listener-recommended logic gate puzzle game for Steam. In the past, we've also talked about Zachtronics' TIS-100 which is similar and Shenzhen IO which is at the circuit level. Oh, and there is The Human Resource Machine by Tomorrow Corporation. A listener recommended the Agile Embedded Podcast, particularly the episode on technical debt. News that Rollercoasters are triggering iPhone 14 and Apple Watch Crash Detection led to a mentions of a blog post about debugging Fitbit's issues with rollercoasters and accelerometers. Visual Studio Code for embedded systems development: You can use CubeMX and Platform.io (here is a how-to) Try out this stm32-for-vscode extension that claims to do what you want (we haven't tried it, tell us if it works) Or you can go more directly with the cortex-debug extension and locally installed ARM GCC package. Don't forget the VSCode Code Spell Checker extension. From the notes for Elecia's class: Where to buy small quantity prototyping components Having looked for an OLED display part in Live Class, I wanted to put together a list of where you might want to look for components, especially for the prototype stage. Adafruit and Sparkfun (and EMSL and a lot of other maker stores). If you are using their code as template or test code, look for their boards to see if you can use them. Worldwide and large components distributors with local distribution: Digikey is worldwide and they resell Adafruit and Sparkfun so if you don't want to start with an "OLED" search on Digikey and sort through the results, well, you can start with easier prototype parts. Farnell is a UK company though they have other names in other locations (Newark in the US and Element14 in Asia and Oceania). If they have your flag, you can probably get cheap shipping. Farnell is usually good for all of Europe. RS Components is also new to me though they seem to stock Adafruit parts as well as general electronics. They have lots of distributors all over the world (including more in Africa than I usually see). AliExpress is huge and worldwide, shipping from Asia. It is hard to find things but searching "Adafruit [part]" or "Sparkfun [part]" and you might find what you want… or a cheaper knockoff. Usually you want results in the Electronic Components and Supplies. Note: if it seems too good to be true it probably is. UK has Pimoroni and Cool Components and OkDo resell Adafruit and Sparkfun as well as other pieces like BBC micro:bit and Raspberry Pi. These may work for European countries. Seeed Studio has a wide variety of parts, the Grove and Components categories have parts that might be interesting. They deliver quickly and cheaply to Oceania and Asia. DFRobot is new to me but looks great. It was recommended for folks in Asia and Oceania. Their parts are resold through Digikey, Arrow, Farnell (Newark). Australia: Little Bird Electronics, Core Electronics, and Altronics Transcript Thank you to our sponsor this week!

We were joined in the studio by the Evil Mad Scientists Lenore Edman and Windell Oskay. Evil Mad Scientist Laboratories (@EMSL) produces the disintegrated 555 Timer kit and 741 Op-Amp kit. These were made in conjunction with Eric Schlaepfer, who also created the Monster 6502. EMSL also makes the Eggbot kit and AxiDraw not-kit (and mini-kit). For a history of the pen plotter, check out Sher Minn's Plotter People talk on YouTube. (They have too many neat things to list here, go look on their page: https://shop.evilmadscientist.com/directory. Or stop into their Sunnyvale, California shop.) We talked about the beauty of boards including Kong Money and ElectroCookie's candy colored shields and Arduino Leonardo. Jepson Herbarium has interesting workshops including one about seaweed. At one workshop, Lenore and Windell got to talk to Josie Iselin, author of The Curious World of Seaweed. Elecia enjoyed Slime: How Algae Created Us, Plague Us, and Just Might Save Us by Ruth Kassinger. Windell was previously on Embedded episode #124: Please Don't Light Yourself on Fire, we mainly talked about the book he co-authored: The Annotated Build-It-Yourself Science Laboratory. Lenore was previously on Embedded episode #40: Mwahaha Session, we talked about EMSL. Our post-show tidepooling was very successful with a variety of nudibranchs, shrimp, seaweed, sea birds, snails, and hermit crabs.

We spoke with Duncan Haldane about creating hardware schematics by writing software code, three dimensional circuits, and bio-inspired jumping robots. Duncan is the CEO of JitX (jitx.com). They recently received Series A funding and are currently hiring engineers. Please mention that you heard about JitX here on Embedded. While earning a PhD at UC Berkeley, Duncan (@DuncanHaldane) also worked on Salto (video) and OpenRoach (github). Transcript

Jonathan Beri spoke with us about the different IoT development tools and how to categorize them. Jonathan (@beriberikix) is the CEO of Golioth (@golioth_iot). He wrote a blog post called An Introduction to The Five Clouds of IoT, breaking the clouds into individual clouds: device, connectivity, data, application, and development. Jonathan was previously on Embedded 222: Virtual Bunnie when he worked for Particle.io. A partial list of the IoT tools we mentioned: ThingsBoard Freeboard Grafana Ubidots Renode Memfault Golioth Particle.io Node-RED Soracom Hologram.io See also A list of IoT platforms – Systev post mentioned in the show (also Building The Infinite Matrix Of Tamagotchis | Hackaday). Transcript

Elizabeth Wharton spoke to us about laws, computers, cybersecurity, and funding education in rural communities. She is a strong proponent of privacy by design and de-identification by default. Liz (@LawyerLiz) is the VP of Operations at Scythe.io (@scythe_io), a company that works in cybersecurity. She won the Cybersecurity or Privacy Woman Law Professional of the Year for 2022 at DefCon. Liz is on the advisory board of the Rural Tech Fund (@ruraltechfund) which strives to reduce the digital divide between rural and urban areas. We mentioned disclose.io and the Computer Fraud and Abuse Act (CFAA, wiki). Transcript

Elecia and Chris are back from vacation and catching up! Today's topics include: last week's burnout episode and what we learned, what is a PSoC and why would you want one, how to get up to speed as a junior engineer, and a few more side quests. The burnout episode with Keith Hildesheim was last week, we encourage you to check it out, we learned some things about ourselves and maybe you will too. Chris mentioned astrophotography and here's the link to the reddit post that inspires him to keep going: astrounding Jupiter video. In case you missed it in the newsletter, which you should definitely sign up for, here's Chris' list of VSCode extensions: AutoScroll - Have a log file open that you're monitoring? This extension keeps the tab scrolled to the bottom at all times. Doxygen Documentation Generator - Quickly generate and pre-fill those tedious doxygen style comments. GitHub Pull Requests and Issues - Make pull-requests or do reviews for Github right in the editor. GitLens - Easily see revision history and "blame" for every line of code in a pretty unobtrusive way. Header source switch - Ever want to switch really quickly to a C file's header (or vice versa)? This adds a keyboard shortcut to do just that. TODO Highlight - Makes those millions of TODOs and FIXMEs light up in a nice neon color so you can't ignore them anymore. Transcript

Keith Hildesheim joined us in an excellent conversation about avoiding burnout at work (and dealing with the aftereffects). Keith mentioned some useful books and articles: Burnout: The Secret to Unlocking the Stress Cycle Mindset: The New Psychology of Success SCARF Model Burnout Is About Your Workplace, Not Your People 5 Ways to Boost Your Resilience at Work How to Make Stress Your Friend Growth Mindset vs. Fixed Mindfulness Exercises 3 Ways to Recharge When You're Burned Out. Transcript Keith also sent over a few charts and checklists which you can see on the website episode notes.

Mike Harrison challenged us to a PIC fight on twitter. Surprisingly, no blood was shed and we mostly talked about LEDs and art installations. Mike's YouTube Channel and his website electricstuff.co.uk. He's on twitter as @mikelectricstuf. Here's a link to what prompted the show: PIC fight on Twitter. His professional hire-him-to-work-on-your-neat-stuff site is whitewing.co.uk For driving LEDs, Mike likes the TI TLC5971: 12-Channel, 16-Bit ES-PWM RGB LED Driver with 3.3V Linear Regulator.

Professor Barbara Liskov spoke with us about the Liskov substitution principle, data abstraction, software crisis, and winning a Turing Award. See Professor Liskov's page at MIT, including her incredible CV.

Gustavo Pezzi spoke with us about using fun and simple systems to explain low-level concepts and how they work in higher-level engineering tasks. For example, teaching microprocessor concepts using Atari 2600 assembly and physics by creating a simple game engine. Gustavo's site is Pikuma.com. He has a free taster course on bit-shifting. We also talked about Atari 2600 Programming with 6502 Assembly and Physics Game Engine Programming. Stella, a multi-platform Atari 2600 emulator For examples of optimizing in different ways, check out this bit hacks page. Gustavo is mentoring for Classpert's Building a Language course. (This is where Elecia teaches Making Embedded Systems.) The conjecture about a shortage of electrical engineers was from The Register. Transcript

Phillip Johnston joined us to talk about how engineering approaches can change over time. This conversation started with Phillip's Embedded Artistry blog post How Our Approach to Abstract Interfaces Has Changed Over the Years. His new course is Designing Embedded Software for Change. Embedded Artistry has a Design Pattern Catalogue (though Elecia was looking at Software design patterns on Wikipedia during the podcast). https://github.com/embvm Phillip is working with Memfault on an ongoing embedded systems panel. The first topic they covered was observability metrics for IoT devices. There is a panel coming up on how to debug embedded devices in production. Some reading that Phillip mentioned: Toward a New Model of Abstraction in Software Engineering by Gregor Kiczales A Procedure for Designing Abstract Interfaces for Device Interface Modules by Kathryn Heninger Britton, R. Alan Parker, David L. Parnas Designing Software for Ease of Extension and Contraction by David L. Parnas (1979) Design Patterns for Embedded Systems in C: An Embedded Software Engineering Toolkit by Bruce Powel Douglass Best Paper Awards in Computer Science from Jeff Huang Creating a Circular Buffer in C and C++ - Embedded Artistry Aardvark I2C/SPI Host Adapter - Total Phase Transcript

Chris and Elecia chat about origami, learning, whether to future proof tools or buy the cheaper option, simulators, and classes. Elecia is gearing up to teach another Making Embedded Systems course. Sign up if you want to be in the Yellow Seahorses cohort! Sign up early and often. Sign up other people. Ask other people to sign themselves up and even more other people. Well, you get the idea. Check out Wokwi! While it looks like it is for Arduino from the front page, there is a lot of work going on to support C/C++ APIs such as the one for Raspberry Pi Pico or the Rust one for the ESP32. Please ask a professor what they'd need to use Wokwi in their class! In episode 158: Programming Is Too Difficult for Humans, we talked about the Ada language and using it on ARM cores. Learn Ada (at AdaCore). News Dead spiders are coming soon to a robot near you Continuous ultrasounds: probably not for swimming Is CERN opening a portal to hell? Scientists claim not. Transcript Thank you to our sponsor this week!

Chris Hobbs talks with Elecia about safety critical systems. Safety-critical systems keep humans alive. Writing software for these embedded systems carries a heavy responsibility. Engineers need to understand how to make code fail safely and how to reduce risks through good design and careful development. The book discussed was Embedded Software Development for Safety-Critical Systems by Chris Hobbs. This discussion was originally for Classpert (where Elecia is teaching her Making Embedded Systems course) and the video is on Classpert's YouTube if you want to see faces. There were many terms with letters and numbers, here is a guide: IEC 61508: Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems; relates to industrial systems and forms the foundation for many other standards ISO 26262: Road vehicles - Functional Safety; extends and specializes IEC 61508 for systems within cards IEC 62304 specifies life cycle requirements for the development of medical software and software within medical devices. It has been adopted as national standards and therefore can be used as a benchmark to comply with regulatory requirements. MISRA C: a set of software development guidelines for the C programming language DO178-C and DO178-B: Software Considerations in Airborne Systems and Equipment Certification are the primary documents by which the certification authorities such as FAA, EASA and Transport Canada approve all commercial software-based aerospace systems ISO/IEC 29119: Software and systems engineering -- Software testing ISO 14971:2019 Medical devices — Application of risk management to medical devices IEC 62304:2006 Medical device software — Software life cycle processes Transcript

Dan White, CEO of Filament Games, spoke to us about educational games, how to make play part of learning, and simulating robots. We also discussed what makes a good (or bad) learning experience, the limits of games as educational tools, and the elements of fun. Roblox is a game platform and game creation system. Filament Games is developing a robot simulator called Roboco. Filament has many games out in the wild, check out their portfolio. If this sounds like fun, check out their careers page. Durf live streams game playing Transcript

Mohit Bhoite makes functional electronic sculptures from components and brass wire. We spoke with him on the hows and whys of making art. Mohit's sculptures, including the Tie Fighter. More on his instagram: mohitbhoite Jiri Prause has a wonderful tutorial on how to make simpler freeform electronics on Instructables. Peter Vogel is another artist making phenomenal freeform electronics. Leonardo Ulian uses electronic components in his art (his don't function but wow). Advice from Mohit on trying this yourself from Bantam Tools. Mohit likes Xuron Pliers Mohit can be found on twitter as @MohitBhoite

Eric Schlaepfer and Windell Oskay are the authors of Open Circuits: The Inner Beauty of Electronic Components. We discussed the inner beauty of a number of electronic components as well as cameras, photography, writing, preparing samples, and terrible title puns. You can pre-order the physical book and get a digital early release copy at NoStarch.com/Open-Circuits Windell is co-founder of Evil Mad Scientist Laboratory (@EMSL). He and Eric have collaborated before on several projects: The Three Fives Kit: A Discrete 555 Timer The 555SE Discrete 555 Timer The XL741 Discrete Op-Amp Kit The 741SE Discrete 741 Op-Amp Eric is also known for the Monster 6502, a 6502 processor made up of individual transistors. Eric also writes on tubetime.us and is on Twitter as @TubeTimeUS Sign up for the Embedded newsletter by the end of July and be entered to win one of these lovely prizes: The Three Fives Kit: A Discrete 555 Timer (two) A copy of Open Circuits (one) Transcript A lovely reject from the book, this is the base of a neon bulb from GE.

Chris and Elecia question embedded systems then answer listener questions about embedded systems. They mostly agree except about one thing which, after some discussion, they agree upon. Mostly. Video of Cissy Strut cover where Chris plays all of the instruments Video where Elecia shows off some programmatic origami and simulation (not discussed but it seemed reasonable retaliation for talking about Chris' video) Dynamic Linker for Cortex-M (github repo) Transcript

Alexandra Covor spoke with us about engineering, making, drawing, school, and what it means to be an artist. Alex's projects are on GitHub and Hackster.io. Her electronics comics can be found as PikaComics on Instagram. The 2022 Open Hardware Summit named Alex as part of the Ada Lovelace Fellowship. Her favorite talk from the summit was Anuradha Reddy talking about Knotty (Naughty) Hardware. Alex works for Zalmotek, a design services firm in Bucharest. We talked about Waylay.io, including their smart pet feeder built on that platform. For example projects for Edge Impulse, they built a tools organizer that uses ML. Transcript

John Catsoulis is the founder of Udamonic and creator of the Forth-based Scamp development board. He spoke with us about Forth, electrical engineering, and writing a technical book. Find out more about Udamonic's Scamp at udamonic.com. There are some hardware projects under the Create menu. The Forth programming language is famous for its small size, portability, and post-fix (RPN) nature. John wrote O'Reilly's Designing Embedded Hardware. While some parts are out of date, the general theory is still good. CuriousMarc's YouTube channel is full of retro-computer goodness. Long ago, Elecia read The Eudaemonic Pie and imagined a life of high tech crime. Please don't tell her if it doesn't hold up well. Transcript

Lead Solution Architect at Cymotive, Benny Meisels spoke with us about implementing embedded software security in cars. The discussion touches ECUs, IoT vehicles, threat and risk analysis, and how reverse engineering plays a role in security testing. Benny works at Cymotive (https://www.cymotive.com/). You can find him on LinkedIn benny-meisels or on Twitter @benny_meisels. Resources for automotive security: Automotive Security Research Group (ASRG) Upstream Security Hacking a VW Golf Power Steering ECU - Part 1 – Willem Melshing's Blog Instrument Cluster (ICM) Simulator: ICSim on github Program | escar USA conference | Embedded Security in Cars Car in a box, also on github and Arduino based: A lower cost approximation of the Toyota PASTA:Portable Automotive Testbed with Adaptability Ghost Peak: Practical Distance Reduction Attacks Against HRP UWB Ranging Framework Laptop Transcript

Laura Abbott of Oxide Computing spoke with us about a silicon bug in the ROM of the NXP LPC55, affecting the TrustZone. More information about the two issues are in the Oxide blog: Another vulnerability in the LPC55S69 ROM Exploiting Undocumented Hardware Blocks in the LPC55S69 More about LPC55S6x and their LPC55Sxx Secure Boot Ghidra is a software reverse engineering framework… and it is one of the NSA's github repositories. Laura will also be speaking about this at Hardwear.io in early June 2022 in Santa Clara. Twitter handles: @hardwear_io, @oxidecomputer, @openlabbott, The vulnerability was filed with NIST: NVD - CVE-2021-31532 Transcript

Chris and Elecia chat about practice, software quality, and empathy for seemingly unmotivated team members. Elecia is teaching another cohort of Making Embedded Systems in the fall, starting late August. There will be reminders between now and then but if you want to sign up, here is the page. The funny and odd music instruction video with the copy-and-paste method of composition. Sign up for the newsletter! Support us on Patreon! Transcript

Tom Anderson returned to the show to describe how transistors and passives work. We discuss everything from vacuum tubes to diodes to transistors (PNP and NPN) to resistors and capacitors. We search for synonyms among the confusing terminology of cathodes, plates, emitters, anodes, grids, bases, and collectors. This was a tech heavy episode so little bit of brushing up on terms may be useful before (or after): Boltzmann constant Physical constant Vacuum tube Diode logic Diode Push–pull converter Transcript.

Ethan Slattery joined us to talk about animals, animal trackers, and how they work. Ethan works for Wildlife Computers. They use the Argos Network for data transfer. He was previously at MBARI and worked with Engineers for Exploration as an undergraduate. Ethan is also known as CrustyAuklet on Twitter and Github. He also has an Instagram page. Things mentioned in the show you might want to know more about: Nautilus Live is a streaming YouTube channel from an ROV exploring the oceans. They have periodic dives where you can ask scientists about what they are seeing, while they are seeing it. Watch discoveries happen in real-time. Or watch the highlight reels on YouTube. Ze Frank also has a YouTube channel about animals called True Facts that it is … not as scientifically minded. And sometimes NSFW. Start with the True Facts about the Ocotupus. (Note he did a parody of a Nautilus Live dive). The Genius of Birds by Jennifer Ackerman Penguin, pangolin, whale shark, weta, you might have heard about those but what about the cassowary? In-depth documentary video, people on the internet are idiots video, and Wikipedia. Transcript

Amanda "w0z" Wozniak spoke with us about her career through biomedical engineering and startups. Amanda contributed a chapter to Building Open Source Hardware: DIY Manufacturing. (A book we spoke with Alicia Gibb about in #289.) Amanda's chapter was titled Design Process: How to Get from Nothing to Something. For more information about the companies we discussed, check out Amanda's LinkedIn page.

Chris and Elecia chat about tools, interrupts, and general happenings. Thank you to Newark for supporting the show! The part that was not guessed was an RF FET: MRF1K50HR5. Elecia found MCU on Eclipse (Eric Styger)'s tutorials on Visual Studio Code for C/C++ with ARM Cortex-M (Part 1). Embedded has a Patreon page where you can get access to the Slack group. The book club is starting Prototype to Product: A Practical Guide for Getting to Market by Alan Cohen. Wokwi Raspberry Pi Pico projects from Elecia: Command Line Interface and PWM Experiments with Logic Analyzer Phillip Johnston of Embedded Artistry and Tyler Hoffman from Memfault are kicking off a quarterly embedded discussion panel. This month is about building embedded systems at scale using device metrics: Embedded Device Observability Metrics Panel Jonathan Beri from Golioth created instructions on how to use USB from WSL2. Copy-editing game. Transcript. Thank you to Newark for sponsoring this episode of Embedded!

Dr. Shirley Davis spoke with us about her book: Diversity, Equity & Inclusion For Dummies. Dr. Davis is a speaker and consultant on diversity, equity, and inclusion topics; her website is drshirleydavis.com. Dr. Davis' books include: Diversity, Equity & Inclusion For Dummies Living Beyond "What If?": Release the Limits and Realize Your Dreams The Seat: How to Get Invited to the Table When You're Over-Performing but Undervalued Reinvent Yourself: Strategies for Achieving Success in Every Area of Your Life Transcript

This week we talk about CircuitPython with Adafruit's Kattni Rembor and Scott Shawcroft. The suggested first board is CircuitPlayground Express with LEDs, sensors, and buttons. CircuitPython is also available for many other boards including the BLE Feather (NRF52832). For a basic introduction take a look at What is CircuitPython and see some example scripts. To dig a little deeper, check out the many resources in Awesome CircuitPython. The whole thing is open source so you can see their code. If you are thinking about contributing (or just want some fun chats), get in touch on the CircuitPython channel of the Adafruit Discord server: adafru.it/discord Many of the language's design choices favor ease-of-use over ready-for-production. Imagine teaching an intro to programming class without worrying what computers will be used or how to get compilers installed on everyone's machines before time runs out. One final note: Kattni did a project that gave us the show title: Piano in the Key of Lime. After we finished recording, Chris asked her why she didn't add a kiwi fruit to her mix… Kattni explained she had limes and they were small. Chris only wanted a different fruit so she could rename it Piano in the Kiwi of Lime. It is always sad when we stop recording too early.

Machine learning engineer and science fiction author S. B. Divya joined us to talk about artificial intelligence, robotics, and humanity. Divya's first full-length book is Machinehood which has been nominated for a Nebula (as was her novella Runtime). You can find more about Divya on her website (sbdivya.com) or on her Wikipedia page. Divya also co-hosted EscapePod, a podcast of science fiction stories. Transcript

Mihir Shah of Royal Circuits joined us to talk about how PCBs are fabricated and how companies are funded. Mihir was CEO of InspectAR before they were acquired by Cadence. Mihir works for Royal Circuits and runs a newsletter called TheAnalog.io We talked about InspectAR on Embedded 384: What Is a Board File? with Liam Cadigan. Transcript for this show This episode is sponsored by Newark, a leading international distributor of industrial and electronic components. From design and testing to production and maintenance, discover why so many choose to partner with Newark!

Jorvon Moss (Odd Jayy) joined us to talk about making robots, steampunk aesthetics, uploading consciousness to AIs, and the importance of drawing. You can find Jay on Twitter (@Odd_Jayy) and Instagram (@odd_jayy). He's been moving his Hackster projects over to Digikey's Maker.io space: www.digikey.com/en/maker. Jay's projects are collected here. Elecia brought up the science fiction book Machinehood by S. B. Divya. Jay returned with Martha Well's Murderbot Diaries. Jay mentioned Mycroft.ai, open source voice assistant. Jay was interviewed by Make Magazine (article). He was on the cover of the magazine; the YouTube video where he was informed was heartwarming. Transcript

Chris and Elecia talk about burnout, a SPI + RTOS bug, newsletters, receiving feedback, Elecia's class, and listener projects. Elecia's Making Embedded Systems course on Classpert is starting a new cohort on March 19th. She gave a live talk related to the class about looking beneath the surface of Arduino (YouTube version). She's excited about the Wokwi Raspberry Pi Pico simulator with C. Want more interesting email? ThePrepared is a weekly email about engineering, infrastructure, and manufacturing news Elecia was interviewed by TheAnalog.io newsletter which is a weekly email about manufacturing and engineering Embedded.fm has a weekly newsletter about topics related to the engineering focused podcast (and transcript) Chris Lott wrote a Hackaday article about episode 404: Uppercase A, Lowercase R M with Reinhard Keil. Elecia enjoyed Thanks for the Feedback: The Science and Art of Receiving Feedback by Douglas Stone and Sheila Heen. Serial Wombat peripheral expander for Arduino will be on Kickstarter soon Chris wanted machine readable datasheets, listener Nick responds with Cyanobyte on github. Infineon (previously Cypress) PSoC (wiki) is a chip/FPGA thing. We talked with Patrick Kane about it in episode 32: Woo Woo Woo

Reinhard Keil joined us to talk about creating the Keil compiler, the 8051 processor, Arm's CMSIS, and the new cloud-based Keil Studio IDE. MDK-Community is a new free-for-non-commercial use, not-code-size restricted version of the Keil compiler (+ everything else). CMSIS is a set of open source components for use with Arm processors. The signal processing and neural net components are optimized for speedy use. The SVD and DAP components are used by tool vendors so there may be components you care about more than others. Keil Studio is Arm's new cloud-based IDE with a debugger that connects to boards on your desk: keil.arm.com. Reinhard talks more about the advantages of cloud-based development in this white paper. Arm Virtual Hardware has multiple integrations, the official product page is www.arm.com/virtual-hardware. The MDK integration and nifty examples are described in the press release. Reinhard mentioned the Ethos-U65 processor for neural networks. The Dragon Book about compilers Transcript

Shawn Hymel spoke to us about creating education videos and written tutorials; marketing by and for engineers; and bowties. You can find Shawn teaching FPGAs, RTOSs and other interesting topics on Digikey's YouTube channel. Shawn also has two embedded Machine Learning courses on Coursera (free!). Or start at his personal site: shawnhymel.com where you can find written tutorials like How to Set Up Raspberry Pi Pico C/C++ Toolchain on Windows with VS Code. Shawn talked about Discovery-Driven Growth: A Breakthrough Process to Reduce Risk and Seize Opportunity by Rita Gunther McGrath and Ian C. Macmillan. He referenced Blue Ocean Strategy: How to Create Uncontested Market Space and Make the Competition Irrelevant by W. Chan Kim and Renée A. Mauborgne Elecia enjoyed The Visual Mba: Two Years of Business School Packed into One Priceless Book of Pure Awesomeness by Jason Barron Embedded has: A Patreon page where you can support us and get into the Slack community A newsletter that sends you a weekly email about the show and little notes Transcripts that you can use to look things up or follow along if the speakers are unclear If you'd like to help the show grow, please write a review. Or share it with a friend. Or send it to your school's Dean of Computer Science and/or Engineering and tell them it should be part of the curriculum to see what engineering lives and careers are like. Or send it to your company's Director of New Hires and say it is important for techy folks to stay current and engaged in embedded systems. Transcript

Chris Svec of iRobot and Phillip Johnston of Embedded Artistry join Christopher and Elecia to talk about the hows and whys of estimating software schedules.. The article that started the discussion was Agile Otter's Platitudes of Doom. You can participate in these sorts of discussions on the Embedded Slack Channel by supporting Embedded on Patreon. On Phillip's Embedded Artistry Website you can find a library of courses, hundreds of free articles, and even more member's only content. Their current focus is developing two new courses: Designing Embedded Software for Change and Abstractions and Interfaces. There are also many great posts on planning and estimation.

Matthew Liberty shared good advice for lowering power. We talk about different ways to measure current (Matt has a nice write-up) and things software can do to decrease power consumption. Sleeping is critical, of course, as is choosing your clock speed and setting the GPIOs to good states. Everything is fine until you start getting into the microamps, then your multimeter measurements may start to fail you. (EEvblog explains why in his uCurrent intro.) Eventually, you may want to measure nanoamp sleep states along with amp-consuming wake states. Matt's Joulescope is a tool to do just that (Kickstarter goes live Feb 19, 2019!), automatically moving between 9 orders of magnitude of dynamic range and graphing the results on your computer. Matthew's consulting company is JetPerch. We mentioned Colin O'Flynn's ChipWhisperer which uses differential power analysis for security attacks. We also talked about Jacob Beningo's post on protecting your tools. Find Matt on Twitter as @mliberty1. Elecia is giving away a chapter of her O'Reilly book, Making Embedded Systems. It is Chapter 10: Reducing Power Consumption. Hit the contact link if you want a copy.

Miro Samek joins us to discuss designing systems, state machines, and teaching courses. Miro's company is Quantum Leaps (state-machine.com) which provides commercial licensing for QP Real-Time Embedded Frameworks. It is an open source project, the code can be found on github: github.com/QuantumLeaps/qpc One of the key concepts is an Active Object which aids in real-time system development, especially in the areas of state machines and concurrency. Miro's (amazing) Modern Embedded System Programming series can be found on his YouTube channel. You can also find Miro on Twitter: @mirosamek

Christopher and Elecia celebrate their 400th episode by discussing what has (and hasn't) changed in embedded systems over the last 9 years

Jen Costillo joined us to talk about voice acting, reverse engineering, podcasting, and dance. Jen's podcast is the Unnamed Reverse Engineering Podcast, found in all your usual podcast places. Jen and her co-host Alvaro were on an episode of Opposable Thumbs podcast. Find Jen on Twitter at @RebelbotJen (also @unnamed_show and @catmachinesSF). Rebelbot.com has her blog and Cat Machines Dance is her site devoted to dance (including the mentioned video about dancers and the pandemic). The Hardware Hacking Handbook: Breaking Embedded Security with Hardware Attacks by Jasper van Woudenberg and Colin O'Flynn Jen is studying voice-overs at VoicetraxSF Jen has been on the show many times in the past. Some of our favorites include 108: Nebarious about security and privacy 82: I Was a Chewbacca Person about movies that influenced their path to engineering 51: There Is No Crying in Strcpy about interviewing 25: Thunderdome for Antennas about RF and manufacturing consumer products 10: Hands Off, Baby about C keywords

Tom Anderson explains radio frequency electronics (RF). Elecia and Christopher try to keep up. We also took a detour into bass guitar electronics. One confusing jargon part is that radio power (in dBm) is discussed as though it is voltage. For example, 10 dBM is 2V peak-to-peak; there is an implied 50 ohm resistor in the P=V*V/R calculation. The the wiki for more about decibel-milliwatts. Tom talked about dollhouses, aka Smith charts (wiki). (We also talked about Bode plots (wiki).) Light travels about 1 foot in 1 nanosecond (11.8 inches, 30 cm). Admiral Grace Hopper is well known for giving out nanoseconds. The guitar company Tom mentioned working with is Alembic. Find Tom's writing on Medium and the Tempo Automation blog. He is on Twitter as @tomacorp and was previously on Embedded 379: Monstrous Cable Corporation.

We spoke with Phillip Johnston (@mbeddedartistry) of Embedded Artistry about consulting, writing, and learning. In the Embedded Artistry welcome page, there is a list of Phillip's favorite articles as well as his most popular articles. Some of Phillip's favorites include: Embedded Rules of Thumb Improving SW with 5 LW Processes Learning from the Boeing 737 MAX saga We also talked about code reviews and some best practices. The Embedded Artistry newsletter is a good way to keep up with embedded topics. You can subscribe to it at embeddedartistry.com/newsletter What are condition variables?

Chris and Elecia ring in the new year with a discussion of projects, hobbies, origami, DMA, music, and the new-and-improved Embedded.fm newsletter... Pepto Bismol can be converted to metal bismuth (YouTube) which can be turned into lovely sculptures. Chris liked his new book, Art of NASA: The Illustrations That Sold the Missions by Piers Bizony. Elecia liked hers, Curved Origami: Unlocking the Secrets of Curved Folding in Easy Steps by Ekaterina Lukasheva Guitar Fart Pedal (Kickstarter) Elecia's Making Embedded Systems course will have a second cohort starting in March 2022. Sign up for the newsletter if you want an announcement (at the bottom of the Embedded.fm Subscribe page).

Limor Fried of Adafruit spoke with us about engineering, education, and business. Some new boards we talked about include the PyGamer and PyBadge (which also has a lower cost version). TinyUSB, an open and tiny USB stack from Hathach. In addition to the many excellent tutorials there are some interesting business related posts on Adafruit Learn: How to Build a Hardware Startup and How to Start a Hackerspace Want to get more involved with the extensive, wonderful, and supportive Adafruit community? Join their Discord chat server or Show and Tell on Wednesdays 7:30pm (ET) followed by Ask an Engineer at 8pm.

Uri Shaked shows us Wokwi, his board and processor simulator. We checked out Arduino code in GDB and then looked at his simulator for the Cortex-M0 Raspberry Pi Pico. First, you should totally look at Wokwi.com. As Christopher noted, signing up for an account shows you many other things. Then you can go look at the processors written in TypeScript in Uri's Github repos: github.com/urish. Find Wokwi on Twitter (@WokwiMakes, Uri is @UriShaked). You can also find Wokwi on Facebook. Uri live-coded development of the Pico's RP2040, it is on Wokwi's YouTube channel. You can find out more about the RP2040 or the AVR core in the ATMega family by taking his free courses on Hackaday: hackaday.io/urishaked (Scroll down for courses.) Uri's homepage is urish.org. You can find The Salsa Beat Machine there as well as some of his other projects. He has a blog there as well as at Wokwi. Susie Hansen - La Salsa Nunca Se Acaba