Welcome Jared Wolff of Circuit Dojo!
Jared is a graduate of the Rochester Institute of Technology (which Chris also considered attending). He did co-ops while there, like we talked about on last week’s episode.
While on co-op at Cisco, he was in the cable group and marveled at the techs doing repairs with magnet wire.
He is an east coast guy at heart, so he moved back to Connecticut eventually
Jared worked at Apple for a while, but the lifestyle is difficult because of time requirements and stressful travel. He was also there when Steve Jobs was still around and there was a bit of over the top hero worship.
Nordic’s early bluetooth chipset was the nRF8001, which was a transceiver over SPI (no micro)
Working for startups was interesting if you thrive on doing a lot of different things
Burnt out on his last startup, decided to ride his motorcycle up and down the west coast. He got sick and ended up diagnosing himself with Valley Fever, a fungal infection prevalent in one of the places he visited.
After healing up, he went to Taiwan for 4-6 monhs.
There is a semiconductor fabrication program at RIT. There is a silicon ingot in a display case out front there.
While recovering from burnout, a previous mentor hit him up for the IoT project.
Mix of international and domestic manufacturing in his past
A lot of military nearby in CT
Comparison quotes with Taiwan, it was only a few dollars more for domestic production.
Currently building a board with an nRF9160 module, the new cellular module from Nordic Semiconductor.
Current status of nRF9160 is that it is shipping and working on different carriers throughout the world on Cat M1 networks.
What does it take to get a modem talking to towers?
Modems abstract commands in software
Jared will be testing for FCC, ISED, CE
Working with Resin
The cellular module is pre-certified but carriers still want you to test your design on their network.
Verizon requires over the air firmware capabilities, in case something goes wrong. The nRF91 firmware OTA is on the application side, which is unusual.
Jared is hoping the modem will have bluetooth at somepoint as well. The external wideband antenna he is using might be good enough.
Crowdfunding had an external antenna included.
There are different categories of cellular service. Most cellphones operate with Cat 4 or Cat 6 connections. The higher the category, the faster the speed.
Cat M1 is the slowest on LTE. NB-IOT is different equipment, so it isn’t even considered to be LTE.
Based on the development from Nordic, Jared is using Zephyr to run his board.
It’s an Real Time Operating System, but “feels” like linux for embedded. Zephyr is built on top of the chip’s SDK. “West” is the downloader that pulls in necessary dependencies, based upon a definition file.
Huge library of boards available
Jared wrote a post on how to create your own drivers on Zephyr
The Device tree maintains swappability
The nRF91 board is based on the adafruit feather form factor. Jared had previously created the air quality wing, which had various sensors:
Humidity / Temp
Compatibility matrix on the Nordic site
Chris recommends checking what kind of coverage you have with open signal.
Though the first board run is no longer for sale, some boards are available soon. You can get a discount on a board at jaredwolff.com/amphour
You can also follow along on Jared’s progress on his blog, where he also writes about firmware tests.
Today’s episode is sponsored by Mouser Electronics. They have been writing about Artificial Intelligence (AI) and how it impacts electronics designers, such as our listners. Paul Golata from Mouser Electronics talks with Chris during the ad break about how AI is changing the world for the better. To check out the free resources, including an eBook about AI, go to TheAmpHour.com/mouserai
We have discussed telepresence before
Chris was able to check out an X Ray machine at mHUB
Chris’s first job was a co-op at Audiopack. This is where he met past guest Dave Young.
Audio is an odd field. Dave did a bunch of videos with Doug Ford before about the field.
Bird RF was another of Chris’s past co-op jobs…but never learned RF while he was there.
Chris got his assembled boards back
EEVBlog video about optimizing for one machine
Video on reflowing QFN
Domestic vs international assembly costs
$4K hand pick and place machine
Chris interviewed Stephen Hawes on the Contextual Electronics Podcast, who is building a DIY pick and place
Mike’s Electric Stuff has a great PnP setup because he knows to re-use parts so often
Mike also recently did a teardown video about an underwater radio
Chris recalls a talk about underwater electronics from 2017, from Nic Bingham
Pu pu platter
Chris recently got back from travel and posted a bunch of new Instagram photos
Dave has been posting more to Instagram as well, lately.
KiCon will be happening in a modified form this year. It will be a developer conversation on October 3rd. Submit questions on social media using the hashtag, #AskKiCadV6
For the 3 mistakes with layout video, Dave was attempting to install the Digikey library, but did not end up finding the part he wanted.
SnapEDA created a KiCad plugin
Check out this awesome photo of an optics table
Louis Rossmann from Rossmann Repair Group joins Dave to discuss Right To Repair legislation and repairability of products, and setting up an industry standard for independent repair.
Also moving his business, realestate, and Louis’s thoughts about what will happen to New York.
Louis’s Youtube Channel.
Right to Repair petition in Australia.
Chris will be out the next few weeks, he’ll be going on honeymoon!
10 year trends
Chris has found some tutors on Upwork for learning about FreeRTOS on the nRF52
Skills in teaching
Chris was having trouble with solderpaste application due to fixed stencils. Dave has done a video of stencil application.
Dave has been trying to track down a 1980s circuit design textbook that he used and enjoyed. He ended up talking on the phone with the 90 year old author.
SBIR grant programs. Past guests Zach Fredin and Michael Ossmann (we think) have been part of SBIR in the past.
The Fully Charged Show reviews the Arrival delivery van (already pre-sold 10K to UPS)
A designer’s guide to fast lithium-ion battery charging
Dave has a Battery/Lithium playlist
Thanks to Wallpaper Flare for the picture of the hipster get-up