The Amp Hour Electronics Podcast

They trade Starlink travel woes and tracker sightings, then dig into Artemis II and the unsung techs who make launches work. A spat over Teensy distribution and closed bootloaders sparks a wider talk about open vs proprietary tooling. They riff on Doom Coding with LLMs as a rubber duck, using phones as serial terminals, Zephyr shells, wild RAM prices, CES battery skepticism, and a Rivian charging deep dive.

Welcome Aaed Musa! Aaed is a YouTuber who builds a variety of robots and a mechanical engineering student at Purdue. He just completed his undergrad degree and is now working on his Master’s degree. I believe he is the first Amp Hour guest who is still a full time student. His channel has a great variety of builds including designing all the way down to gearboxes. Aaed says the MIT “mini cheetah” launched many low(er) costs builds of robots, including his own. Boston Dynamics (and many others) announced their new ATLAS robotics platform at CES this year. FOC motor controller Backlash is a measure of how much movement you have between the teeth of gears (and thus how accurate you can be with open loop control) Ball bearing balancing robot Inverse kinematics Past guest of the show James Bruton was a model for the builds that Aaed does what does the glue look like His recent build uses…rope…to build a robot dog? A Capstan drive has virtually zero backlash “relatively new rope” DM20 High precision speed reducer using rope the impacts of materials on design processes Juicero Relationship with classmates and professors as a YouTuber Purdue Engineering Aaed picked up electronics from youtube What’s his take on LLMs? Making next CARA open source New video recently came out about a spinning top bulk of the cost is in the motors and motor controllers growing up in the age of youtubers

Welcome Dr Mark Palmeri, professor at Duke University! Mark has been at Duke since 1996, and has completed undergraduate, graduate, medical, and PhD degrees here (!) He has focused on making medical devices and now teaches others to do the same in his Biomedical Engineering (BME) courses Verification and Validation (v&v) is a large constraint in getting a regulated medical device to market BME design fellows is a program that guides students towards real world use cases and design projects The courses that Mark runs reminds Chris of “automatic job offers” that Chris has heard about for classes like those taught by former guest Larry Sears (at CWRU). Also SMPS design courses at UT Dallas and microarchitecture courses like those taught at University of Michigan. Teaching the skills of troubleshooting / debug Putting together circuits like Legos There are difficulties when teaching students with various levels of experience, namely how deep to go on any particular subject and how much background to provide. Mark has been flipping a circuit course on its head, instead prompting students with ideas like “how do you capture bio signals electronically and pull them into a microcontroller” Tools of the trade for Mark’s courses include KiCad ngspice (built in to KiCad) Jupyter notebooks VS code Git Zephyr Talking about power as an intuition builder, as opposed to currents or voltages V&V requires that you have a quality management system (QMS) IEC60601 Going through companies that have  QMS can be a shorter path for bringing a device to market Even face shields needed to go through that process when COVID hit Firmware and embedded in BME at graduate level Mark and students in BME Design Fellows course have been working on a Tympanometer, targeted at resource constrained industries Mark also teaches students how to use Zephyr, as opposed to how most educational programs migrate towards arduino A challenge for teaching Zephyr is the devicetreed They target Nordic Semiconductor parts, which have great support and educational resources Mark experienced a “vertical learning curve” when first migrating designs to Zephyr a few years ago Complicating things is that most students haven’t coded in C, if they have done much code at all Teaching how to lock to a particular version with Zephyr manifests Using CI/CD for automated builds Focusing on state machines early on, using Zephyr’s state machine framework (SMF) All of Mark’s courses are on github under his username mlp6 Teaching stack vs heap Mark only ever has taken one official progrmming course The benefits of experiential learning Accreditation is a constant challenge with non-standard courses and testing Duke is taking retrospective and prospective looks at the space of education Problem sets are moot these days Mark gave a great example about teaching a student about Bode Plots “Thats a trick problem” is something Mark hears wrt testing (when it’s definitely not) “Getting the reps in” is an important concept in educational contexts, and something Chris really resonates with Building open ended problems vs closed The more open ended a problem, the more time it take to grade / evaluate TI-85 / 83 / 92 calculators Jupyter notebooks as a way to track progress and have students show their work More about the tympanometer project They have been working with Duke hospital, a major benefit for Mark and his BME colleagues Continuous middle ear infection that causes scarring that causes lifelong loss Sound reflection under vacuum is an indicator that more testing is needed The key innovation is making it lower cost and allow a layperson to do the screening to hand off a child to get more screening at a pro clinic BME Design Fellow students getting to design the various parts of the design They have multiple sources of funding: private, nih, etc Value engineering in medical space Mark points out the philosophical question on whether you can reduce costs by reducing testing … but thinking about whyat that takes to satisfy that need Find Mark online mlp6 on Github His Duke homepage tymp project article Find him on LinkedIn Duke BME design fellows / on LinkedIn

Chris got back from his honeymoon to the Galapagos, see photos on the updated version of his blog. Dave encountered a super secret podcast location Before leaving on vacation, Chris went to an event mentioned in episode 708 launching a new Tektronix scope. The parent company has been Danaher -> Fortive -> Ralliant (now based out of Raleigh) Large budget events Don Mcmillan is technically funny Open Circuit The Way Things Work Discman teardown Neo the home robot Humane AI pin ‘tugging on the nerd heartstring’ Nikola / Trevor Norton Auto concept cars Rigol MHO 900 videos, already hacked, paid hack EEVblog forum Unknown chinese fpga Stephen Hawes working on a PCB that can be laser cut for super quick turn boards Oxide and Friends podcast KiCon (US) 2025 Talks

Dr. Barry Marshall, a Nobel Prize-winning physician and microbiologist, discusses his groundbreaking discovery of Helicobacter pylori as the cause of stomach ulcers. He reflects on the journey that led to the invention of the noninvasive urea breath test and how it changed ulcer diagnoses. Barry shares his enthusiasm for vintage electronics and highlights the importance of antibiotics in ulcer treatment while cautioning about their side effects. With humorous anecdotes about his Nobel Prize experience, he emphasizes the global impact of his work on health and treatment.

Welcome Davide Andrea, author or The Electronic Connector Book! And many thanks to Blues for sponsoring this episode of The Amp Hour! Get 10% off your next order in their online store for a development kit by using the code AMPHOUR. Davide is an engineer working on Battery Management Systems at Elithion He got into writing and editing books via a postcard sent to him after he gave a talk For many years he was an editor at Artech house He works on Lithium BMS systems for large setups How do young engineers learn about connectors, but for tribal knowledge within larger companies? Digikey catalog is a good search for connectors overall Industrial cinch by Harting Should you design a custom connector (“no”) Davide also built and maintains an online tool for finding connectors called Identiconn Fretting is when vibration causes a connector to fail Davide had to go to Bell Labs docs to look up some specs Chris remarked that Identiconn is a McMaster (Carr) style browsing experience Vendors divide based on how the fields are set up, because that is actually logical for them selling parts. It’s harder for finding/discovering components though. On distributor sites, the connectors are grouped by how they were bought Chris asked Davide about things that have gone wrong in his career with connectors FFC doesn’t connect back into the socket after the tab is ripped away ribbon cable vs ffc, CIC vs FPC IDC – insulation displacement connector Davide has filled in with generated terms where there are no defined language for a family/type of connector, such as with “bump idc” connectors “dual beam? Chris and Davide did a joint search for the high density CM4 connector that mounts the Raspberry Pi module to another board Gender of connectors (note: there is a great discussion about the historical nature of using gender for connectors in the book) Pin vs plastic gender Shrouded vs enshrouded gaziatea (sic) – poem from the 1800 USB type A connector Self mating APC7 – self mting connector Anderson connectors TNC BNC search PFFE for the dielectric on a BNC/TNC Magnetic connectors with pogo pins Example connector from Hyte Crimps were designed in the 50s The source of having so many power connectors is … imperialism? tahiti / fiji / nz all have different connectors Why antennas are male/female is…money? And regulatory silliness via the FCC Davide has also written about and is working on lithium ion batteries A sodium ion battery book (self published, unlike the LiIon books) should be out next year The Connector Book is self published. Your purchase directly supports Davide’s work…and you get the web tools for free! “peak lithium” What is required when refining sodium for batteries? The voltage range and charging needs are different for Sodium Ion. For instance, the range goes from 4V to 2V Find Davide on his various websites, on LinkedIn, on StackExchange, and on reddit

Thanks to our sponsor Blues this week! Visit the Blues store and use the code AMPHOUR to get 10% off your first order of a kit. Capacitors go pop on Dave’s audio setup, the Presonus monitors Ground loops causing HDMI cable sparking Chris was watching Jetman videos and got an ‘Is that real?’ from the kid. We find ourselves asking the same with all the AI generated video these days. Fight between mehdi/electroboom and walter lewin about KVL Arduino bought by Qualcomm! They also released the Arduino Uno Q, a single board computer running Debian that also has a beefy microcontroller running Zephyr Daves post on X about the purchase Arduino switched to Zephyr A new enabler of this complex mix of embedded, linux, AI, and ML is a software offering from Arduino called App lab Spacey Hardware meetup – ACES  Veritasium is PE owned now Chris will be going to a Tektronix event for new gear and past guest Alan Wolke (W2AEW) is giving a class Chris has been rebooting his website to follow the ideas of the Small Web Follow #electronicscreators on YouTube to not be subject to algorithmic steering Chris has been getting into gridfinity after discussing it a few shows ago. Altium changed their pricing again…but it might be lower? Hard to tell Check out the features coming to KiCad in v10 YOLO = “You Only Look Once”, Chris learned about it from OpenMV

In this engaging discussion, Joren Vaes, a design engineer at SOFICS with expertise in high-speed analog and wireline PHY/IP development, dives into the complexities of modern IC design. He emphasizes the crucial role of simulation in handling intricate parasitics across many metal layers and explains the challenges posed by massive DRC rules. Joren also shares insights into cutting-edge technologies like FinFETs and CFETs, the impact of electromigration on device reliability, and how to navigate the transition from digital to analog processes at high frequencies.

Contextual Electronics is “still a thing”. Sydney hosted the International Astronautical Congress (IAC). The IAC is the “big space event of the year,” held annually in a different city. Chris noted that US space funding seems low, leading some friends to move from NASA to private industry. Dave recorded two walkaround videos: a 30-minute bird’s eye view using a GoPro on a pole and a physical hour-long walkaround. Large companies had private stands, while smaller, two-man companies had sub-booths within their country’s larger rented stand (e.g., South Africa, Germany, Poland). Niche companies included those selling “space connectors,” described as regular connectors sold at potentially 10 times the price to space customers. Australia had a large presence, with stands for the country and individual states (Victoria, New South Wales, Tasmania) hosting local niche space gear firms. Dave toured a new, completely mobile Mission Control facility built into a semi-trailer van. This unit is designed as a generic platform with screens, server racks, and redundant power, allowing any space company to install their own servers and operate anywhere in Australia. An Australian company specialized in “Space lube” (lubricants for satellites and actuators), necessary because water-based lubricants would boil off or freeze up and cause gear to seize. Chris has a new “quasi obsession” with the old technology of DIN rail. He is using 3D printers to mount development boards onto DIN rail to organize his desk. DIN rail is common in Australia and Europe for electrical switchboards and automation equipment (PLCs, power supplies). Dave sent a photo of “Fish Pointer’s” organized desk, which Chris identified as using “Gridfinity,” an ad hoc, modular standard popular in the 3D printing community, often associated with Zack Friedman of Voidstar Labs. Dave runs a Creality K1 3D printer that is networked, allowing him to control and print remotely. Chris purchased a filament dryer for only $42 to combat the issue of filament going brittle due to moisture. Dave recounted his attempt to sort 330 tins of salvaged parts (feet, spacers, grommets) from vintage test gear. The space industry is currently “so hot” due to private funding, unlike the “dead” industry 10 to 15 years ago. It is now easy to book a payload slot on a launch vehicle like SpaceX. Dave said that Firefly was actually “begging” people to put payloads on its Moonlander to help fund the mission, though that’s source unknown. It was supported by CPLS as part of NASA. The Commodore Corporation recently changed hands, and a consortium of enthusiasts released a new Commodore 64 Ultimate, featuring a transparent keyboard PCB signed by original designers, including Jerry Ellsworth. The appeal is nostalgia, as modern chips far outperform the 6510 CPU it uses. Chris bought a split, ergonomic Corne V4 keyboard (RP2040 chip) from AliExpress for $68. The key feature is working with Vial, a pleasant web serial-based app for reconfiguring key mappings. Dave stated he hates split keyboards and rechargeable keyboards that only last a week. Dave is installing 75 kWh of beefy outdoor battery packs (800-900 kg total) received “free” due to a government subsidy. He poured a new, completely reinforced concrete slab rated for over 1,500 kg to support the batteries on a flat surface, using pre-welded mesh instead of tying rebar. The new system includes an 8 kW inverter. Dave intends to install a changeover switch to run the house off the batteries if the power grid fails. Dave noted he mainly wants the “warm fuzzy” feeling of running his entire house on solar and batteries.

Welcome Jerry Twomey (Effective Electrons) author of the book, Applied Embedded Electronics: Design Essentials for Robust Systems. Chris first heard Jerry on Embedded.fm last year. Jerry’s Background and Book Motivation: Jerry shares his quick history, moving from the Boston area to San Jose (Silicon Valley) and eventually to San Diego, where he has worked across diverse sectors including consumer electronics, aerospace, defense projects, DARPA research, and medical electronics. His book focuses on how to develop robust systems, providing guidance that is timeless rather than applications manuals that quickly become outdated. The Analog Problem: Although modern systems may be digital end-to-end, Jerry emphasizes that the predominant causes of failure and design difficulties are often analog in nature. Academic study often teaches ideal signals but neglects real-world issues like inductance, noise, and cross-coupling. Consulting Experience & Troubleshooting: Jerry discusses being called in to fix systems that failed strenuous regulatory testing for medical devices, where reliability is first and foremost (similar to an aerospace way of thinking). Failures often stemmed from basic issues like a lack of ESD protection, absence of error correction in data streams, insufficient detection of errors, and common mode noise rejection problems. High-Speed Data and Signal Integrity: At high data rates, communication becomes a “communications channel problem,” not truly a digital one. When bits are underneath a tenth of a nanosecond, the communication turns into multiple standing wave transitions. The two primary limits on performance are rise and fall times and distance traveled. Real-World Applications: Jerry has worked extensively on medical devices, including early-generation Dexcom glucose monitoring systems (two on-body monitors and a hospital insulin pump/monitor), and a wearable EEG monitor. He also worked on a system that required packing five video cameras into an endoscope distal head, measuring 11 mm in diameter and 13 mm long. Architecting Systems and Identifying Bottlenecks: When starting a new project, Jerry suggests defining needs and interfaces and looking at the system as a black box. Engineering time should focus on the bottleneck—the hardest part of the system. For medical implantables, this might be minimizing power consumption down to virtually nothing, which could take up 90% of the effort. Power System Design: Jerry advises purchasing commercial AC-to-DC converters due to competitive pricing. He notes that switching supplies (buck converters) commonly introduce noise that can lead to EMI failures or corrupt sensitive analog front ends. A classic case of “digital thinking in an analog scenario” is when a sensitive analog front end is powered by a noisy switching converter. Working with Embedded Teams: Jerry prefers guiding embedded teams toward “self-discovery,” using bench time and empirical measurement (such as comparing grounds on a scope) to demonstrate non-ideal connections and grounding issues. He advises against the “seagull manager” approach. Grounding Best Practices: For integrated circuits (chips), designs must be fully differential because securing a good hard ground reference is impossible. On singular circuit boards, a common uncut ground plane (dedicated ground plane, often multiple layers stitched together with vias) is the recommended approach. Cutting the ground plane is discouraged as it can create a slot antenna, increasing the signal radiating from the board by about 7 dB. Jerry has published rules on grounding. Engineering Intuition vs. LLMs: Jerry notes that intuition is gathered through painful learning experiences and guidance from experienced designers. He expresses concern over the reliance on LLMs (Language Learning Models), which, while improving, can confidently provide incorrect answers, especially regarding complex topics like signal grounding. Limits to Moore’s Law: CMOS scaling is approaching physical limits, likely unable to go below 10 or 11 nanometers. Modern performance gains are achieved through more parallel processing, not significantly faster clock rates, which have plateaued around 5 GHz due to parasitics and timing limitations. Jerry’s article discusses this topic. RISC Architectures: The industry benefits from migrating to RISC (Reduced Instruction Set Computing) architectures (like ARM) because they eliminate useless architecture and transistors associated with complex instruction sets (like x86). Find Jerry on Effective Electrons and on LinkedIn