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The Amp Hour

The Amp Hour (Chris Gammell and David L Jones)

The Amp Hour is a weekly conversation about electronics and the people who design them.

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27 episodes
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Avg 1 hr 5 min
English

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#716
February 26 · 1 hr 2 min
Electronics Manufacturing History with David Ray
Thanks to our sponsor for this episode, SeaSats! Check out their open positions making autonomous ocean vehicles. Welcome David Ray of Cyber City Circuits • The “Retro Electro” Series: David explains his passion for writing historical articles for Digi Key, focusing on “giants” like Orstead whose contributions to electricity are often overlooked. • Career Background: David details his path from Marine Corps radio repair to cash register and Motorola radio repair. • Starting the Business: In late 2019, David cashed in his retirement to buy pick-and-place machines and start his own factory. • Teaching the First Lady: David recounts the story of teaching First Lady Jill Biden how to solder during a summer camp. • Growth via Twitter: For the first few years, 95% of his revenue came from relationships built on Twitter (X). • The Kit Business: David discusses his “Soldering Kit of the Month” program, noting that while fun, the kit business is exhausting and low-margin. • Equipment & Machines: A discussion on why he uses Charm High machines and his strong advice to buy new equipment rather than used industrial machines, which are often sold because they are “used up”. • Stencils & Paste: David advocates for framed stencils and GC10 solder paste, which is shelf-stable and prevents cold solder joints. • Soldering Physics: Insights into the thermodynamics of soldering, especially the difficulty of working with 2 oz copper boards. • John Fluke History: David previews his research on John Fluke, explaining that Fluke meters became yellow because the Navy had trouble finding gray ones on the ground. • Upcoming Articles: David mentions future work on the history of Op-amps and strain gauges. • Business Services: Overview of Cyber City Circuits’ services, including reverse engineering, obsolescence engineering, and free DFM (Design for Manufacturing) consulting. • Success Philosophy: David shares his “Monopoly mindset,” viewing business setbacks as “chance cards,” and stresses that persistence is the only way to avoid failure. Links from David Website List: Cyber City Circuits Website: www.CyberCityCircuits.com PCB Event Badges: www.BadgesBadgesBadges.com X: www.x.com/MakeAugusta Collection of Retro Electro Articles: https://cybercitycircuits.com/retro-electro-the-little-told-history-of-electronics/ Digikey Magazine: https://www.digikey.com/en/emedia GC10 Solder Paste: www.BuyGC10.com
#715
February 10 · 58 min
Shiny New Pebble with Eric Migicovsky
Welcome Eric Migicovsky of Pebble! Pebble is back after Eric worked with Google to open source PebbleOS and he reaquired the naming rights Eric returns to the hardware space after 7 years, including working at yCombinator, a famous accelerator for early stage startups, and on Beeper, a cross platform app for messaging. While discussing the difficulties of hardware project, Chris brought up a recent post about a high wattage lamp project HN One thing Eric likes about hardware projects vs software is that "hardware projects can be done" as in they have a defined end state A more recent project is a smart ring - The Index 01. The non-replaceable battery is driven by the product specs, also the need for reliability The ring doesn't immediately need to be in range of a phone, it syncs the memory after the fact Pebble is no longer a VC backed startup with a subscription model, so that changes a lot of constraints Initially they sold 2 million watches, and 250 million in sales Eric is driven by "gadgets". He read "pen computing" and "popular mechanics" as a kid Consumer companies vs other types (and why Eric likes the former) Pebble went through different phases The team spent 6 months in China, designing the first consumer version and working directly with factories CTO of (original) Pebble, Andrew Witte, was a somewhat early guest of The Amp Hour How much did the China ecosystem drive design decisions? There was no such thing as a smartwatch factory (but are there ever now!) The book Apple in China is supposed to be a great read and mirrors the Pebble Experience We heard from Chrissy Meyer when she was on the show about working with the Apple Watch manufacturing proces Water proof methods codeveloping in China It's an interative process of submerging designs in a glass vessel with pressure and bubbles seep out of the device at different points The remedy? According to Eric: "More Glue" :-D Eric shares his process on a YouTube channel called Tick Talk (not to be confused with the shortform video site) There is a video with the CEO of SiFli, makers of the Bluetooth chip that is in the most recent Pebble devices One interesting feature is a custom bus to the Sharp-made ePaper-like screen used onboard FreeRTOS pebble OS What is PebbleOS? It's targeted at an m33 class ARM chip and the kernel is FreeRTOS The bluetooth stack is nimBLE Eric went back and forth on whether to port to Zephyr for the Bluetooth stack and hw support from vendors like Nordic Semiconductor The Index 01 ring is Dialog Semiconductor (now part of Renesas) part One challenge is that rings have different sizes...so they mill the rings based on orders. The larger rings get an extra battery!
#714
February 3 · 1 hr 17 min
The Measurement Blues with Martin Rowe
Welcome Martin Rowe of EE World! Martin is a long time journalist in the electronics space, having worked at magazines like EDN, Test and Measurement World, EE World, and more! Kenneth Wyatt Concentrated vs diffuse information Product reviews Unitrend scope video Tek 5 series B Wirecutter for test equipment / parts Skepticism Webinars - 3 levels Martin has an HP34401A early model Touring T&M companies Littelfuse Martin is in the Boston area Boxborough has multiple EMI labs Article on building an anechoic chamber PCB East was in Boxborough now in Worcester ("Wuh - Stah" :-D ) International Microwave Symposium (IMS) inBoston this year What is driving the Boston ecosystem? NYU wireless 6G summit Components trickling down into the other parts of the industry Ted Rappaport from NYU writing a paper Open RAN 5G standalone vs nonstandalone Poster session ISAC Test equipment has to test everything leading edge 3GPP The impacts of satellite connectivity IoT still talking about LTE 5G modems and battery life Private networks Automation software The Measurement Blues song, among others Find him online Martin Rowe on LinkedIn EEworldonline Martin sent over some links related the things we discussed during the episode 6G discussions: How things have changed. We assembled a timeline of the topics so you can see what's come and gone Nokia Bell Labs’ Peter Vetter talks 6G research Live from the Brooklyn 6G Summitd Teardown: HP 8112A pulse generator - I bought this at a flea market. MIT holds these once a month April through October. I go every year to buy things for teardowns and to take photos. DSL router uses parts from old phones - Heard about this from a European telecom newsletter and just had to get the details The slide keyboard is back, in a 5G phone - Video interview from 2020. I mentioned the Psion Organizer. The designer of this phone used to work for Psion. He designs beautiful products. Tryout: two low-cost USB inline meters and a load - My latest. This was the one where the audio in the videos seemed overdubbed. I uploaded the videos again using different file names. Seems OK now.
#713
January 26 · 1 hr 9 min
Rubber Duck Incarnate
Dave is back from vacation. He should have bought a Starlink mini (not as cheap as we thought) because his coverage was very poor throughout the trip. Space twitter Artemis II is going up soon (early Feb 2026) Billy makes artemis go up Sparkfun and Adafruit are on the outs PJRC (and Paul Stoffregen) makes the Teensy and it is now produced exclusively by Sparfkun The pinout is open but the bootloader is proprietary and sold as the magic black box. Paul's wrote about what was happening on the EEVblog forum Tim Lamb (Trash80) talked about teensy in his devices on episode 292 Chris modified a Tag Connect 10 pin footprint for an upcoming design RAM prices are wild right now! After following a tutorial on "Doom Coding", Chris picked up using Claude Code A friend pointed out that more horizontal, open source programs like KiCad (version 10 coming soon) will have an advantage with LLMs/coding assistants over more vertically integrated tools. The vertical tools won't be able to move as fast. Also in the Doom Coding exercise, Chris found an app called Terminus that allows connecting an Android device (and maybe iOS?) and getting a terminal interface from the phone using a USB-C cable in OTG mode. Zephyr builds in lots of capabilities Chris loves using Zephyr shells to build interfaces (even custom ones) to standard functions in Zephyr CES wrapped a week or two before this recording. The Donut lab solid state battery proposed impossible specs. Some engineers modified a Rivian to try and make the Cannonball Run. It was an interesting look into battery packs and what it takes to charge them fast. Dave and Chris took a long roadtrip to the Deep Space Network back in 2017. Piers Rocks has a great video about how PIOs work on the RP2xxx chips from Raspberry Pi The Raspberry Pi should always be viewed from the perspective of "what is cheapest". The RP team mentioned that drove the decisions of external flash on the RP2xxx boards Past guest Jeff Geerling talked about some of the pricing challenges with RAM prices increasing
#712
January 20 · 58 min
Robots Everywhere with Aaed Musa
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
#711
Dec 22, 2025 · 1 hr 29 min
Medical Electronics Education with Mark Palmeri
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
#710
Dec 6, 2025 · 56 min
Tugging on the Nerd Heartstring
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