The Amp Hour

By The Amp Hour (Chris Gammell and David L Jones)Science Technology Education How To Physics

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The Amp Hour episodes

March 04Back on the road in '26
Chris will be having a meetup in London March 8th, 2026 click here for more info. He will also be at Embedded World the following week at various events.
Dave is also headed to a meetup in Sydney that he has presented at in the past.
The "lazy man move" for meetup organizers: scheduling events within walking distance of home to simplify travel logistics.
Chris provides details on his latest high-density hardware project, a 22mm circular board packed with 0201 components, Bluetooth, and a suite of sensors, noting a move from BGA to QFN for better assembly reliability.
There is significant skepticism regarding "solid-state transformers" and tech articles claiming they will replace the traditional power grid, with the hosts citing efficiency losses that become massive at megawatt scales.
A fascinating look into global supply chains reveals how a single AI prompt can be traced back through layers of manufacturing to sugarcane fermentation and high-purity quartz mines in Spruce Pine, North Carolina.
The creeping normalization of biometric face scanning in public spaces, from water park lockers to international airport terminals.
The marketing tactics behind Donut Lab’s solid-state battery claims, explaining how "independent third-party testing" can be carefully hand-picked to avoid industry standards. They want us to talk about it like this
The nuances of UL certification explains how companies sometimes use specific lab reports to imply broader official endorsements that do not actually exist.
Dave shares his experience watching the show Silicon Valley with his son and discusses the "hideous accuracy" of the Australian public service comedy Utopia.
The pros and cons of modular hardware are debated, covering the Framework laptop’s "Ship of Theseus" repairability model versus high-end gaming tablets like the Asus ROG Flow Z13.
Dave’s viral social media quest for the best Linux distribution leads to a consensus on Linux Mint as the top choice for beginners, fueling the ongoing joke about the "Year of the Linux Desktop".
Recent industry news highlights the release candidate for KiCad 10 and the discovery of a three-cent Paduk microcontroller performing auxiliary functions inside Rode wireless microphones.
Pimoroni did extreme an cooling project back in 2024 that successfully overclocked the RP2350 microcontroller to 800 MHz. We just found out about it from a post from Jeff Geerling.
1 hr
February 26Electronics 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
1 hr 3 min
February 10Shiny 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!
59 min
February 03The 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.
1 hr 18 min
January 26Rubber 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
1 hr 10 min
January 20Robots 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
59 min
December 22, 2025Medical 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
1 hr 30 min
December 06, 2025Tugging 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
57 min
November 10, 2025 Nobel Prize Winner Dr Barry Marshall
Dr Barry Marshall won the 2005 Nobel Prize in Physiology or Medicine for discovery of the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease.
But Barry is also an electronics hobbyist and vintage HP and Tek oscilloscope and vintage computer enthusiast. He visited the EEVBlog lab and sat down with Dave for an impromptu discussion about all sorts of things.
https://www.nobelprize.org/prizes/medicine/2005/marshall/facts/
51 min
November 03, 2025All the Connectors with Davide Andrea
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
1 hr 6 min