The Amp Hour

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Missle Man with Bruce Simson Apr 12, 2021

Show notes

Bruce Simpson from the Xjet Youtube channel joins Dave to discuss RC aircraft and creating an international incident by developing a DIY cruise missle! He runs the world’s longest running blog website! He’s on Twitter

Pulsejet vs Xjet technology
A visit from the New Zealand intelligence agency
V1 vs V2 German missle technology
Using electrostatic gradient and thermal grading for maintaining altitude
Tricopters
What keeps a quadcopter in the air?
CAA in NZ trying to shut him down and regulation red tape
DJI drones and Geofencing
DJI firmware bricking
Tradeoff of rotor numbers. Octocopters vs Hex vs Quad
Shrouded blades and the Coanda effect
Beating Betz's Law
The futility of hydrogen powered cars
The absurdity of magnetic fuel savers, 5G USB shields and other scams
FPV vs Line of Sight flying
Video transmission technology and bandwidth
Model jet turbine engines vs full scale
Parkinson's disease and management strategies

Firmware Deployment and Troubleshooting with Akbar Dhanaliwala Apr 06, 2021

Show notes

Welcome Akbar Dhanaliwala, Founder and CEO of Lager Data!

Akbar has been doing 15 years of embedded systems
He has a Mech E background and attended Stanford engineering for grad school.
Solar panel robot cleaner
They had evisioned a device that enabled wireless debug with JLink
JLink with RPi
Dev Ops
War stories
Various types of testing
Consulting right after school via his consultancy Pocobor
One of their first customers was Solar City (later purchased by Tesla).
Wireless system using ZigBee to monitor panels and inverters. The bridge in the inverter, the gateway is in the house. Some are still deployed in the field.
They were the "low bid", which means they didn't work for much as consultants (but it lead to many other gigs)
Testing Zigbee by walking down the block
Pocobor - It's "Robocop spelled backwards"
Another company was Juul when they were still called Plume
They had an office in Dogpatch (in SF)
Being a technology center, it lead to many interesting gigs
Stanford Junior car (VW)

Testing big stuff
Why did Pocobor end?
Minna was a spinoff in the sex toy industry in 2009. They are still around.
Akbar moved to NYC and joined a startup called Ringly with a friend who started the company
They got the product to market, a device that indicates when you have new messages on your phone without looking at a screen
Required a complex flex board interally because it was such a small, odd form factor in a ring.
Burned out after a lot of time in China
Step tracking in the ring using algorithm development (difficult because the hand does a lot of other movements than just walking)
Getting data out was really hard because you couldn't just plug in a JLink
No automation or regression testing
Updates could break OTA DFU
ANCS protocol
All of his experiences inspired Lager Data
CI/CD
Runs the test when you push the code
IDE dependent tools
Gateway
Debug probe built in
Wrapper tools
Lager command line makes it easier to script actions
Dockerized build environments
Gateway has IO you can access via the command line
Unity test framework
Quaternions
Writing test data
Lager gdb server
3rd party build
GitHub actions
TDD - test driven development
System test
Run python scripts on gateway
Past guest Jason Huggins (Tapster) also talked about the importance of testing
Akbar recommends implementing a simple shell in embedded projects
Testing over UART
For more info or to sign for for a demo, check out lagerdata.com

NFT Schematics Mar 28, 2021

Show notes

Non-Fngible Tokens for schematics(reddit discussion)
Apple 1 schematic
Drafting tables
Quartus II
Chris is working with a Mech E who can iterate on very detailed designs using resin. Dave has torn down a resin printer (SLA)
Dave had a 121GW prototype made from Resin
Digikey printing on the tape
Make your own parts kit
Paper about thermoelectric generators
These are much much lower output than an RTG, because the input power source is so much lower
Video by Anton Petrov, Dave did a response video.
Chris is interested in a new solar MPPT and battery charging chip, BQ25798
Energy harvesting chip turn on requirements
Solar panels
When should you architect your whole system (write all the code) from scratch?
Dave's new ATEM switcher has a lot of customized code, not just drivers (maybe a custom OS?)
Buying IP
Speaking of developing an OS, Bell Labs just released Plan 9, including a Raspberry Pi image. The name is drawn from the terrible Plan 9 from Outer Space movie. Chris used to watch terrible movies like this. The one he tried to remember was "Invasion of the Saucer Men"
A self-study plan posted on Hacker News
Buy a kit for the area you're interested in (in the above case, a brain interface kit)
Don't have a starting project? Chris recommends you follow past guest Ben Eater's videos and follow along with a kit.
Chris and Dave both like the PCBite system
Intel announced they're expanding their foundry capabilities. Chris predicts they will be spinning out the chip side soon (as a different company)
TSMC is planning to build in Arizona for $35B
Texas Fabs shut down from the power outages. NXP is just now recovering.

Thanks to Housing Works Auctions for the pictures of Beanie Babies

Efinix FPGAs with Sammy Cheung Mar 22, 2021

Show notes

Welcome Sammy Cheung, CEO of Efinix!

Efinix makes FPGAs in a fabless model.
They started in 2012, but really got started with their first product in 2017
Co-founder is Tony Ngai (CTO), both he and Sammy used to work at Altera
At first they were trying to make a higher growth company, to possibly get aquired quickly. In 2015, when Intel acquired Altera, there was a pause to all acquisition talks.
Interestingly, Xilinx is an investor, as well as Samsung
Building the first chip (the Trion) required Architecture, Software, IC design. All things have to work together.
Licensing IP
They ended up selling 1M units
Does first chip have to be niche?
ASSP
Trion is big in Computer Vision (CV) and sensing. It has hardware interfaces for Cameras / MIPI interface
Chip architecture also matters
Many CV users wanted to put inferencing functions on board, especially because it's fast and flexible.
In traditional FPGAs, the routing switch is separate from the logic element. In the Efinix "Fine grain architecture", it's more closely coupled. See the image in this IEEE Spectrum article.
Logic elements are more "equivalent" logic elements
Trion on 40 nm Low Power (LP) process
The soon-to-be released Titanium is different. It has an upgraded architecture (though it's still XLR).
Early users have seen a 4x improvement
Sammy says these chips are meant as much more than a Bridge device (like a CPLD)
Not doing a ton of IP internally, OK with pulling in other companies' IP
Other vendors are integrating Efinix FPGA silicon into SIPs, using Chiplet form factors.
Simplified power bringup
Because doing specific FPGAs to integrate with others
Applications
- Reconfigurable accelerator
- Security
- Auto
4 mask sets for Trion, 3 for Titanium
Titanium is on a 16 nm process node.
These chips are not meant for server farms, but they're also not chasing the low end.
Features in the Titanium
- DSP is more complex than just a MAC block
- Targeting DSP blocks
- Soft IP offerings
- RISC V
Next 5 years they expect more processor offerings
Can run processor at 400-500 MHz
"Domain Specific SOC"
The Efinix RISCV offering is based off of the Vex RISC-V design, which won the 2018 Softcore contest, designed by Charles Papon
Efinix hopes these chips will enable AI engineers
Will Efinix use the open toolchain discussed on The Amp Hour regularly? No plans currently. Sammy contends that super competitve devices require vertical integration.
Efinix has a tool called the Interface Designer
Separate core from peripherals
Sammy is excited about interesting future applications like automotive vision. The car is a "moving supercomputer"
Q2 events showing Titanium and Dev kits are on the way. There will be parts out in the Summer, including the first released the TI60 out in Q3.
What are their challenges looking forward? Not money or tech, but how the company will change as they grow

Firmware Update Capabilities Mar 14, 2021

Show notes

This week's episode is sponsored by Mouser Electronics. They joined us to talk about wide bandgap semiconductors, including materials like SiC and GaN. Learn more by checking out their dedicated applications page on the topic by visiting TheAmpHour.com/bandgap

Projects without firmware
EEVblog #1024
Zephyr LTS
Gary Johnston, founder of JayCar, has passed away. Watch this Interview with Karl
MIPS is now using RISC V ISA
Forrest Mims on The Amp Hour
MITS
Will Silicon Valley recover after COVID?
Louis Rossman announcement video
Louis discussed Right to Repair when he was on The Amp Hour on episode 507
Custom cable
Chris did an unboxing and teardown of the Joulescope on Contextual Electronics
Mars Helicopter
uSupply update video
Fluke 87 thread
Please fill out the 2021 Listener Survey!

Microwave measurement with Joel Dunsmore Mar 08, 2021

Show notes

Welcome, Joel Dunsmore!

Joe worked on the HP 8753 and also wrote The Handbook of Microwave Component Measurement (now in its 2nd edition)

APC-7 connectors
HP 8753 was one of the first pieces of test equipment to ship with a microcontroller (a washing machine controller!)
Error correction in a VNA
What is a Vector Network Analyzer (VNA)?
VNAs are great for impedance measurement and antenna measurement. They can measure phase angle, which a scalar network analyzer cannot.
ADS simulator (Microwave Linear Simulator)
DANL - Displayed Average Noise Level
Measuring and correcting
David Root
X Parameter
VNA Calibration
- Open, short, and load
- offset open and offset load
Fringing capacitance
Squeezing the cable changes the dielectric constant
Correcting for bad TV cables
Combline conductors
Getting intuitive feel
5G system vs ham radio
Cable cost for high-end measurements
Keysight VNAs go up to 72 GHz
Above 70 GHz there are head units
Above 30GHz it's referred to as "mm wave" (millimeter wave)
Who is using 100 GHz? Most satcom is 50 GHz
Losses in space are lower
Beamforming is required at such high frequencies
Starlink teardown
Phased array antenna
Professor Gabriel Rabiiz at UCSD
What's inside the box?
- CW signal
- Swept wave
- Signal separator or reflectometer
- directional coupler
PNA 0-70 GHz
The key is to try to make a pure signal
Modern test equipment should measure everything
Network vs spectrum analyzer
Hardware swept filter
Digital filter techniques
Alan Wolke video about using a scope as a VNA
Noise / Noise figures
Make it cold
Phase noise or jitter
Driving away from cell tower
The crystal in the phone is slightly different from the tower
Multipath
MIMO
PXI form factor
64 calibration elements put on by a robot (!)
"little badnesses stack up so fast"
For million dollar customer problems, Joel gets to be the fixer
Drifting
Solving a 50 Hz vs 60 Hz problem
Microwave components measurements book
- 1st edition released in 2009
- 2nd edition released in 2019
Why are things changing?
Noise figure analyzer
Premeasure stuff
QAM measurements
Automatic fixture removal
Higher port counts are more common. Joel gave a presentation on multiport and multi-site optimization.
Measuring a differential amplifer
32 port system for mimo test set
- n*n-1/2
- n*((n-1)/2)
12 port testers are popular
Tom Lee
6 steps you need to do
First thing to do with a VNA is try it without any calibration
Have a regular test setup: Tape thing down
NIST
The official reference of impedance is distance
Calibration from an instrument side is the cal sticker (meets spec on the sheet)
Load calibration is error correction
Who is doing the most complex things?
- Mil / Aero is top tier
- Cell towers are next
- Then handsets

Many thanks to Joel and Shamree for making this appearance possible and for donating the books for our giveaway. Joel regularly monitors and responds to comments on the Keysight forum, so that's a good way to get ahold of him. If you'd like to be entered for the chance to win a copy of the 2nd edition of Joel's book, please fill out the survey via this link or using the form below. You must include your email address in order to be entered, but it will only be used for the contest. Loading…

Recalling Recalls Mar 01, 2021

Show notes

This week our sponsor is Keysight Technologies, who are ramping up a new contest called “Stump The Experts” and is focused on Keysight’s 5G testing technologies. You can learn more and enter the contest by going to TheAmpHour.com/5G

Dave tore down his ATEM mini ISO
Internally there is a Xilinx Zynq that has an $1800 single piece price
The pipelined data path can also do things like Chromakey
Texas power outage
Lawrence Krause
Dave is upgrading his solar
Can solar be used as a hedge on inflation?
North vs south facing depends on your latitude.
String inverter vs microinveter
John Edmond of Cree (one of our earliest guests!) talking about LEDs and SiC mosfets
Past guest Martin Lorton made a set of videos about inspecting solar panels
DC isolator fires
Product recall
RCA TV recall
Dave had to ship out shims to counteract underspec'd thickness of the PCB on 121GW
Tesla recall
Takata airbag recall
Dave's video (#10) about how a rubberband cost millions of dollars!
Marco Reps did a build of an 8.5 digit voltmeter
Perserverance landed on Mars! So awesome
The "Marketing Camera" was an off-the-shelf camera from FLIR
Real Engineering did a video about all of the features on the new rover
Fry's is shutting down
US administration is pushing for more silicon investment (fabs)

Thanks to Wikipedia for the representative rendering of Dave and Chris trying to remember recalls

Footprints and Symbols with Natasha Baker Feb 22, 2021

Show notes

Welcome, Natasha Baker, Founder and CEO of SnapEDA!

Natasha has an EE background, she got her start working on tools at National Instruments
She was reading IPC-7351 specs early on. What's in there?
All about how to create footprints, with different density levels, depending on the complexity of your board
- Most
- Nominal
- Neast
A new version is coming out soon, check IPC.org for more info
With corporate sponsorship, anyone can participate (and Natasha recommends it!)
Interesting discussion around using an X shaped pad under a QFP
Later, Natasha got interested in the marketing side of business.
She found that she was designing board and footprints taking a ton of time
Zen and the Art of Motorcycle Maintenance
- Gumption
- Craftsmanship
When Natasha started, she was coding it herself. She taught herself using a Django tutorial meant for a website that organizes books. It still has some form on the current site.
A site like SnapEDA is difficulat because it's starting from no content. They had free "requests" to figure out what people wanted early on. They had some user generated models at the beginning, but they were not preferred.
Natasha estimates there are nearly 1 billion parts in the ecosystem, in part because of the number of connector companies permutations.
Semiconductor acquisitions has messed with a lot of part number data.
Natasha took SnapEDA through the yCombinator program, focusing on it full time. We have had two shows in the past about YC
- Luke Iseman, former head of hardware at YC
- The Upverter team, who also went through YC
YC has continued funding hardware companies since then, even though SaaS have been more popular
Eric Migicovski, founder of Pebble, is now running hardware at YC
During interviews with engineers, trust was the biggest/most common thing brought up
SnapEDA has a neutral meta format, which means each component goes through a PCB exporter to match your specific CAD tool.
Chris didn't realize there is a batch export for KiCad. This will be less necessary for the upcoming v6 version. There is also a KiCad plugin.
Natasha hopes in the future they can offer additional engineering content
- Simulation models
- IBIS
- Subcircuits
Microdecisions
Working with old school chip companies
Component registrations
Free samples
Analytics/Insights
Lizard brain vs logical brain
40% browse parts directly through site. Others arrive via external search engines. There are tools built directly into ExpressPCB and Proteus. SnapEDA created external plugins for Altium and KiCad.
InstaBuild allows engineers to pull pin tables out of datasheet PDFs. The resulting symbol is only available to the user who created it (for now, at least)
Popularity of platforms using SnapEDA (in order)
1. Altium
2. EAGLE
3. Orcad/KiCad/Allegro (tied for 3rd)
Launching some cool things in the next month or so
SnapEDA has published about popular components via EETimes in the past.
Feedback welcome! You can reach them via the SnapEDA chat bubble (on the site), via email at support@snapeda.com, or via the "report issues" dialog on each part page

Living Through Chipageddon Feb 16, 2021

Show notes

We recorded video on the episode this week! Previously, Dave and Chris had tested Zencastr video.

https://www.youtube.com/watch?v=toFetYb4xvs

Chipageddon has arrived, a confluence of factors such as COVID and resulting forecasting errors (esp in automotive), the increasing need for parts to service the 5G ecosystem (towers and handsets), and general consolidation of the chip industry.
Tesla Founders
Samsung is looking at building a new fab in the US
Dave has been working with a "DIY Trezor wallet" that was only EAGLE files on GitHub
Eagle to KiCad conversion video in 5.99 (Also in 5.1.18)
Past guest Jesse Vincent talked about automating scripts at KiCon 2019
Chris is starting a course for people looking to become a technical consultant:

https://www.youtube.com/watch?v=5t5L8KAo0_g

Interested in being part of the beta group? You can apply here.
Schottky on the EEVblog forum did some amazing renders using Blender
Blender
Glamor shots were a thing in the early 90s. The Rock did one. Apparently there are still a few studios open in the US.
Dave made a DIY lightbox, based on Big Clive's setup. Chris uses this "light tent" that has a top porthole.
There was a live show with electronics YouTubers
Liam Fraser who was on the episode last week with the Raspberry Pi team wrote about the "journey to Raspberry silicon"
Dave is working on a new device that might need multiple micros swapped in. Chris mentioned this is the idea behind the Sparkfun Micromod system, which didn't seem super useful otherwise.
Reusing a commodity connector like the M.2 connector is not a new idea, but the M.2 looks cool!
Dave is not interested in learning Micropython or Circuitpython for this project because of the time involved.

Embedded Hardware with the Raspberry Pi Team Feb 08, 2021

Show notes

Welcome James Adams, Liam Fraser and Luke Wren of Raspberry Pi Trading!

Raspberry Pi Trading vs Raspberry Pi Foundation
The RP2040 is a new custom chip that Raspberry Pi released and is integrated on the Pico dev board
2016 start of RP2040
Why the Pico form factor? Driver was cost (common answer throughout this interview)
DIP form factor is interesting
Two layer board to keep costs down
PIO started in 2017. The idea has been around since the 60s though.
Like a processor but very stripped down. The main thing is that it's very deterministic.
Demos online like driving a VGA monitor (and a demo on how to do it yourself)
Limits are tight timing
The RP2040 documentation and getting started guide (datasheet)
It's extra easy to get started using MicroPython
Liam doing chip architecture work now, with new hardware experience in it
Being able to push and pull across the documentation
Raspberry Pi Trading has a flat structure so the engineers float across different projects.
They always maintain a super low cost focus. How does that affect things internally?
- Building out test systems and automation at the factories
- Cost engineering
- Pushing cost savings back into silicon
- Volume discounts
No reset button (because of cost)
SWD is via a few wires (because of cost)
Using another Pico as a programmer
Benchmarks:
- .93 DMIPS
- Two core
- Symmetric cores for processing
- Comparing 2 M0+ vs M4
- Using 2nd core as debugger for first core (a forthcoming software project)
To answer Dave's question about the RP2040 being a microcontroller vs microprocessor in episode 528, it's a "flashless microntroller"
The flash is external (because of cost). They can create 20,000 die per wafer on 40 nm (!?!)
The prototype of the Pico/RP2040 devices had flash, but they decided it was better to trade out for SRAM.
The Pico team is 3 or 4 people mostly, with many more working on the Linux side of the house.
RP2040 SDK
Chris asks if the RP2040 will be used as co-processing on the RPi5, but it's unlikely (because of cost).
What about future chip development?
- Will they design big silicon like for future versions of the Raspberry Pi? Probably not (because of cost)
- RISC V? Why didn't the use it here?
  - During the time of the design freeze, the M0+ was the best fit, because it was low cycles per instruction and you can push the M0+ to higher clock rates.
Interested in buying RP2040 to integrate on your projects? Probably Q2 availability. It's tough to get your hands on Pico boards right now, as well, but you can sign up to be notified on different distributor sites.
The boards come on tape and reel (because of cost) and because they expect some people to integrate these directly into future projects using the castellated edges.
What are people missing about the boards?
- USB host should be possible soon
- Demos using USB ethernet
- PIO
- Interpolator
- Super Mario Kart
RPi Pico's PIO vs the BBB PRU
Is the RP2040 Low power?
- It was design on the 40 nm LP process.
- Dormant / coma modes
- Stops all of the clocks running
- GPIO edge wakes it back up
- Memory powerdowns
- Dynamic power is pretty good, as that's what they optimized for
- Static power is not as good
CM4
- Genesis of the compute module
- James designed RPi4
- Temp ranges were targeted to work in harsher environments than the RPi4 would expect to see for commercial settings.
- On the CM4 they swapped out ethernet phy
- There is a compliance program for CM4 (Roger Thornton), so you can get your device tested using the same compliance house
- The cost basis was not as we speculated in episode 528.
Why the dual micro HDMI on the RPi4? Because they expect some people to be using it like a computer.
The PI 400 is a keyboard based computer.
Chip choice on the Pi
- 2835 chip on the original
- James used to work for Broadcom as well as Eben Upton (on TAH 97!)
- RPi4 is 2711 on 28 nm
- 2835 was a co-processor for phones
Why are there reduced schematics for the RPi4?
How you can help
- Pull requests to SDK
- Contribute to Rust support
Got to blinky in a couple days with the chip
They are looking at FreeRTOS support in the future
Follow everyone on Twitter: James, Liam, and Luke

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