Got a CNC machine that uses a parallel port interface? What’s the best way to control it? In the field of CNC machines, GRBL is the means of transmitting G-code via a serial communications connection. So, basically, what you can do is run a serial communications connection to an Arduino, then break out a parallel port from there to connector your CNC machine.
20200727/https://hackaday.com/2014/09/16/usb-to-db25-adapter-uses-grbl-for-parallel-port-cnc-communication/
This is an interesting Hackaday article on Jan Czochralski, who started the history of silicon crystal growing.
20200727/https://hackaday.com/2020/07/22/jan-czochralski-and-the-silicon-revolution/
I put this in the random-software category because it is somewhat
related, I guess. Interesting Hackaday article on a NASA satellite
where the hardware was well extended past its original mission,
NEOWISE. The main thing I have to say software-related, looks like if
you have plenty of good foresight, you can keep using a hardware
system through software adaptation.
20200727/https://hackaday.com/2020/07/22/the-wise-in-neowise-how-a-hibernating-satellite-awoke-to-discover-the-comet/
Another report of a Raspberry Pi supercomputer? Come on, that has ought to be another over-hyped report on the power of the VidCore IV GPUs. Well, this project’s main purpose was to create a visual art form that is also somewhat of a good demonstrative example of how a supercomputer works. It was originally designed on Raspberry Pi B’s, then later upgraded to B+’s. So, yes, stuck on 100 Mbps Ethernet, doesn’t make for a very good communications bus for any sophisticated uses. It is “kinetic sculpture” because each Raspberry Pi node is mounted on an articulating arm. In all senses, not very practical, but for sure, designed for entertainment.
20200727/https://magpi.raspberrypi.org/articles/seemore
Currently the computer is disassembled and stored in boxes. Alas, its primary design goal, that of being put up on display, ended as a long-term failure. Besides, if you take a look at the described audience, you can tell they’re pretty much all already geeks anyways.
In addition to Open Cores, here is yet another project to build modern computer components as Open Hardware. This one, this time, is instead very much a one-man effort. This one person, however, is an academic, so it appears, so even though it is a one-man effort, it appears the project gets plenty of publicity. There is also a nice blog with plenty of information on lessons learned from this one person.
The FPGA board is an ICO board, and the name of the board mounting project for the CPU is ICOZIP.
20200727/https://github.com/ZipCPU/icozip
20200727/http://icoboard.org/
20200727/https://github.com/ZipCPU/zipcpu
20200727/http://zipcpu.com/
20200727/http://zipcpu.com/about/
This is a great article on four keys to making FPGA hardware designs that “just work.” Yes, it does hinge upon the idea of formal verification, clearly specifying the behavior in terms of “contracts,” and testing all possible code paths.
20200727/http://zipcpu.com/formal/2020/06/12/four-keys.html
This is a great article on phase-locked-loop (PLL) problems and debugging them. Clock syncing in advanced sequential logic is no joke!
20200727/http://zipcpu.com/blog/2017/09/14/even-i-get-stuck.html
When finding this random article on putting together a switched-mode power supply system for the Raspberry Pi:
20200727/https://rootsaid.com/diy-voltage-regulator-pi/
I found out about the site’s sponsor, UTSource, another electronics components distributor? Yes, this one is Shenzen-based. Looks like they aim to compete in the same market as Digi-Key. They started out as a small business about 15 years ago, so they say, then they gradually grew bigger to the business they are today. So, definitely not around as long as Digi-Key, but purportedly they grew much faster. Yeah, but really, that sounds quite tongue-and-cheek to say 15 years is “fast,” right? Definitely when compared with software, but the electronics industry operates on a different time scale.
And… wait for it, they also have a PCB Builder service too! When did they get it? Looking at the site history in the Internet Archive Wayback Machine, looks like they sprouted it up several months before Digi-Key. However, they only do business with one PCB service aggregator, NextPCB, and therefore their minimum order quantity is 5. So, even though Digi-Key came late to the party with their PCB Builder service, they came out with a competitive offering nonetheless.
20200727/http://www.utsource.net/
20200727/http://www.utsource.net/Home/PCBService
20200727/http://www.utsource.net/AboutUs
20200727/https://web.archive.org/web/20190201000000*/http://www.utsource.net/
20200727/https://web.archive.org/web/20191106162517/http://www.utsource.net/
How do you generate pick-and-place files for through hole components in KiCad? The default exporter omits through-hole components. Well, here’s the rationale for doing so. Through-hole pick-and-place is a lot more expensive than surface-mount pick-and-place because all the pins need to be properly aligned before insertion. Surface-mount is more forgiving, and therefore cheaper.
Also, wondering why KiCad’s mounting holes are plated rather than non-plated? Two reasons. First of all, it’s typically cheaper for the manufacturer. Second, the plating helps protect the hole against wear and tear from the screw.
20200724/DuckDuckGo kicad pick and place through hole
20200724/https://electronics.stackexchange.com/questions/456671/kicad-no-footprint-for-automated-placement
20200724/https://forum.kicad.info/t/create-a-mounting-hole/6737
Again, I reiterate, because this is important! Through-hole automated assembly is fully possible. With the correct machines, through-hole components can be placed on the board. Provided that the components can handle the temperature range, solder paste and reflow soldering is also fully possible with through-hole components, by stuffing the holes with solder paste before stuffing the components onto the board. For temperature-sensitive components, wave soldering will need to be used instead.
I already beaten this topic down many times, but I must revisit it one more time. SCSI over parallel port? Sure, I know, it’s not possible since parallel port communications doesn’t have enough of the right type of I/O bits to carry SCSI communications, though the physical connector has enough pins. Matter of fact, classic Macintosh computers use a DB-25 connector for SCSI.
The interesting thing though is that some vendor hardware was designed to be dual-mode, either parallel port or SCSI port mode.
20200724/DuckDuckGo scsi over parallel port
20200724/https://retrocomputing.stackexchange.com/questions/15577/why-did-scsi-require-so-many-pins
20200724/https://retrocomputing.stackexchange.com/questions/6589/connecting-iomega-zip-parallel-port-to-modern-pc
20200724/DuckDuckGo db-25 scsi
20200724/https://en.wikipedia.org/wiki/D-subminiature
UPDATE 2020-10-26: I wasn’t entirely right by saying it wasn’t possible. If you apply some restrictions on the SCSI protocol, you can essentially carry SCSI communications over a parallel port. Here’s how.
Iniatiator control signals, max 4:
Oh wow, a simple search on tab routing brought me to two more good turnkey PCB manufacturers. Basically, it is the “mouse ears” and “mouse bites” panelization technique.
Bittele Electronics Inc (7pcb) is located in Toronto, Canada. Screaming Circuits apperas to be located in Milwaukee, Wisconsin, USA.
20200724/DuckDuckGo tab routing
20200724/https://www.7pcb.com/blog/tab-routing.php
20200724/https://www.7pcb.com/about-bittele.php
20200724/https://blog.screamingcircuits.com/2014/06/tab-routing-panelization.html
20200724/https://www.screamingcircuits.com/
20200724/https://www.screamingcircuits.com/about
20200724/https://www.screamingcircuits.com/about/history
Looking at Digi-Key’s list of PCB printers, and of those that offer PCBs in quantity of one, I discovered another U.S.-based PCB assembler, Advanced Circuits (4PCB), based in Colorado, USA.
20200724/https://www.4pcb.com/
20200724/https://www.4pcb.com/Assembly-Services.html
Sierra Circuits (California, USA) also does turn-key:
20200724/https://www.protoexpress.com/
This is an interesting Instructable on how to build a speaker with excellent acoustics using a DSP and a 3D printed case.
20200723/https://www.instructables.com/id/Mr-Speaker-3D-Printed-DSP-Portable-Speaker/