Two events reminded me recently that you can’t have too many choices for solving a sourcing problem.
A client and I had finished a simple PCB design, got it off to OSH Park and OSH Stencils, and turned attention to the BOM. All passives but one: in my shop already, so check. The remaining one and some connectors: Digikey has them, so check mark. The central IC that is the point of the board: Digikey, zero. Mouser, zero. Other suppliers we’d heard of, zero. Anyplace in the USA, zero. China, only on breakouts. Ouch. Europe: “Rutronik”. Who? After a day of thrashing I noticed this is the chip manufacturer’s favorite distributor in Europe, and I should be able to trust them. I had to establish a business account but all was well until we got to shipping: Big ouch. And this huge minimum shipping wasn’t for Startrek teleportation beaming from their warehouse to my bench, as the fee implied. They predicted 72 hours, but later we found that was if you’re in the EU. Oh, right. When it wasn’t at my door in 72 hours I dug up an Excel spreadsheet via a well disguised link on my account page and on one row was a red “warning dot”. More digging and I decoded this warning to translate to English as ” six days estimated delivery from order date”. But the chips should be here in time for the reflow oven and all is well even if the client’s wallet is thinner than desired.
Just days later another client and I were deciding what parts of a new board really needed breadboarding to give us confidence in a major respin and this forced an immediate order of a few piddly parts (note to self: as soon as the part is on the short list for a design, order three of them.) I was inhaling to commiserate about shipping when the client reminded me that Arrow isn’t charging anything for shipping. Period. Zero, no matter what size the order is. I was startled, as this has been going on for months and I just assumed it was a one shot, short time thing and had let it fade from my memory. Instead I was able to throw the part number and quantity for a special FET I want to try out into the client’s order, smiling at the idea and my share of the shipping will be zero. Nice.
Meanwhile, the US rep for the big Euro distributor contacted me and we’ve agreed I will call her before risking another big wad on shipping that isn’t even fast in relation to the cost.
So, one arrow moved to the front of the quiver and a new one added for Euro parts that the US hasn’t discovered or that got too popular for supply here to keep up with.
Dave Jones has made a new video that shunts theory and directly demonstrates the effects of bypass capacitors. It’s worth 30 minutes to get an understanding of this that will serve you well if you’re making custom digital circuits and may wet your appetite for a deeper dive such as with Dave’s other video on the subject or section seven of chapter one of The Art of Electronics.
A whole bunch of generous folks kicked in for the triembed.org domain renewal this year and we won’t have to deal with this for a long, long time. THANK YOU!
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2018 has a good chance of seeing embedded development accelerate sharply. Best wishes to the interest group and the wider community during this new year.
GitHub, GitLab, and Atlassian BitBucket are all sites that offer git repository hosting. But if you create a repo named “Test” with BitBucket, then you copy/paste the slug URL and feed it to “git clone” as usual, the URL is forced to all lower case “test” and you end up with a clone of your repo in directory(folder) “test”. This stinks, for example, with common library directory naming conventions.
After thrashing around in the team settings, thinking I’d just missed the way to override the default URL, it occurred to me this might be a feature, not a bug. Sure enough:
(“Stash” is simply Atlassian’s downloadable repo hosting system, effectively giving a customer a “Bitbucket” system within their enterprise)
This is just a classic bug report pattern. Who knows what caused the Bitbucket architect to decide not to honor the name spelling when creating the slug (the text box holding the URL you copy from to do a clone). But, the fact that one can simply modify the URL and end up with a target directory with any pattern of upper/lowercase makes it clear that they COULD offer an “honor name capitalization” radio button to override their sacred cow default, but they choose not to, with the lamest of lame excuses:
“Given that it is possible to modify the clone URL to include a camel-cased repository name (which creates a camel-cased repository directory when cloning), this is unlikely to be a priority in the near future.”
But this latest submission was started in 2013 and “resolved” in 2015, two years ago. Maybe it’s time to submit it again.
- On October 20th Nordic Semiconductor is conducting an all-day seminar with members of their R&D organization on Friday, October 20th. They’ll cover the nRF52 chip series, Bluetooth 5, Bluetooth Mesh, and “802.15.4 and Thread: Mesh technologies for IoT applications”. They say somewhere that attendees will receive an nRF52 dev board. Registration here.
- Monday, November 1st at Duke University the IEEE/Robotics (aka TAR) meeting will offer a presentation about Duke’s humanoid robot project. (This is not the same as the IEEE project being done at the Forge Initiative ) Again: this meeting is not at NC State for November. Pizza and beverages at 6:20 pm, the program starts at 7 pm. Location, parking, and other details and painless “register now” button to gauge the pizza order are here. Program:
- Humans and Autonomy Lab – Humans’ Interaction with Autonomous Systems, by Dr. Michael Clamann
- Explainable AI, by Dr. Alexander Stimpson
- Experiment on Humans’ Trust in Risk-Aware Autonomy, by Dr. Lixiao Huang
- November 8th at the McKimmon Center at NC State will be PCB Carolina, “North Carolina’s Premier Electronics Trade Show”. They offer outstanding food, a range of technical presentations and many vendor and organization booths to do with PCB design and production, and electronic assembly as well as related vendor’s wares. Details here.
- Problem of the Month
- Paul presented his “sorting a mixture of colored marbles” mechanical+electronics problem and gathered ideas submitted by the attendees
- Details of problem-solving sessions are available here.
- LTSpice talk. The materials are on Carl’s GitHub repository here and he’ll update it as the project matures.
- Glenn Smith showed a charging base he build for his Ham Radio. There was a 3D printed (ABS plastic) base with a LiPo charger board inside. It plugs into his car dash (not via cigarette lighter port, but a more robust connection).
- Paul MacDougal showed his mushroom growing box. A plastic tub with a 12V fan, a CO2 sensor, and a DHT22 temperature/humidity sensor. An Arduino monitors the CO2 and turns on the fan at 800 ppm CO2 and turns off the fan at 750 ppm CO2.
- Paul MacDougal showed his pushup counter based on the horizontal ultrasound sensor technique suggested in the September meeting. It worked well “in the lab”, which has hardwood floors, but not so well on carpet. He will continue to develop this project.
- General discussion and final questions
Archive of past meeting slides, videos, code and design files