mnml.blog

Backing Up Raspberry Pi on MacOS

I’ve been fortunate to have never lost any data in my computing life. It is fortunate because it will happen. No matter how good your backup system is it will happen eventually. I have always been able to fall back on a second, third, or in some cases, forth copy of data. I use a lot of Raspberry Pis. They are all booting off of MicroSD cards. They are notorious for dying because the SD cards are not designed for significant read/write cycles. It is important to back them up. Even if you don’t save important information on them it will save you countless hours in setup time. It isn’t hard to do. Below are my steps on a Mac.

From terminal find the SD card.

>> diskutil list

You should have several devices (/dev/disk*) listed. Find the one that matches your SD card. Mine is /dev/disk2

Copy the SD card to your Mac.

>> sudo dd if=/dev/disk2 of=/users/name/backup-directory/backup-file.dmg

if is the input file. of is the output file. You can save this anywhere you like on your system. This can take several minutes to an hour depending on the size of the card. Don’t interrupt the process if it takes a long time. That is normal.

To restore to another SD, unarchive the file, run the same command, but reverse the input and output files.

>> sudo dd if=/users/name/backup-directory/backup-file.dmg of=/dev/disk2 

All my Pis use 32Gb drives. I don’t want a bunch of 32Gb files so I archive the backups in Finder after this process is completed.

I’m most concerned with backups for the systems that run my 3D printers. I run Octoprint and stream video on all my printers. I don’t want to go through the setup process if I lose a card. Last year I moved all these systems from Raspian to DietPi. DietPi is much smaller and allows for a RAMDisk with minimal logging. This is less taxing on the SD card. I have not lost an SD card since moving to DietPi.

Rivers of Information

I haven’t put much time into writing recently. I’ve pursued other projects. I was talking with my girlfriend and she noted that I’m posting a lot on Twitter. When I thought about why I posted there I realized that I have developed a nicely curated list of accounts that I follow and posting is almost frictionless. This is particularly true when I want to post a quick status update of a project that I’m working on.

The problem with this is that I’m neglecting my blog, my data store, my memories by placing them in someone else’s silo. I didn’t use social media accounts for years. I’ve come to realize that they can be useful places to meet people with similar hobbies and share ideas. I have met many thoughtful, talented people over Twitter and have found a lot of inspiration. I want to interact with those people and I cannot expect them to come to this site. Even if I put in comments or discussion features it is unreasonable. I probably have less than 50 followers.

Besides Twitter, I also spend a large part of my day reading and jotting down notes. I add links to my Safari reading list. I put ideas in notebooks. The vast majority of these will never be looked at again and most of my ideas will never see the light of day. It would be nice to put them on my blog so that they are easily searchable and so that others can see them and possibly draw inspiration. I have followed Dave Winer for years, decades even. I believe it was Dave that popularized the idea of information rivers. These are streams of links, news, quotes, etc. I was inspired by the idea and decided to create another section on my site that holds a river of random information.

I see the river as something like “stream of consciousness” blogging. It isn’t something to think about. It doesn’t require proofreading. It’s a never-ending post-it note. Earlier I said that I haven’t written much lately, but I have been thinking. If I capture those thoughts on my blog then there will be more here to think about and maybe help to occasionally brighten the proverbial light bulb. The main issue is eliminating friction and I think I have a workflow that reduces the friction sufficiently for me to use the river as my main collection of thought.

Along with the river I’m working to add IndieWeb functionality such as webmentions, websub, and webpub. The idea is to silo here and syndicate elsewhere. I’ve made some progress. You may see some odd formatting in a few of the first webmentions. I apologize in advance. It will get better.

This is Frisket

Frisket the cat

This is Frisket. That is Frisket, like brisket, but with an F. Frisket is a cat. She annoys me. She crawls inside my pants when I go to the restroom. She jumps in the shower with me every morning and scratches my legs while she scrambles to get out. She bites my ankles when I go up the stairs. She falls asleep in the pantry and then wakes up scared in the middle of online meetings. She licks my ears and wakes me up just when the dream was getting good. She once fell asleep on my laptop keyboard while I was watching TV and posted a random issue to Github. Note to self, turn off unlock with Apple Watch on the laptop.

I dislike Frisket. There are four people that love Frisket though. I love those four people very much. I don’t have to like Frisket, but I love her too.

Say Yes To Living

Every other Thursday I have a special evening with one of my kids. Tonight was with my youngest son. As always we had a great time. We grabbed an ice cream. We sat at the park and ate it, then we played at the playground. We went home and swam for an hour. He took off his swim vest tonight, jumped in and swam out for the first time! I was so proud. Then we ate a sandwich and he went home to his mom.

I was reflecting afterwards. He always has fun because he always says yes. He doesn’t care what we do. I love these nights also because I don’t care what the kids want to do. I just want to be with them. We need to say yes more and live. Life is too short for no.

Republican States are Expanding Their Power Over Elections

Several days ago, Nick Corasaniti and Reid J. Epstein of The New York Times published an article outlining several of the ways Republican controlled states are using to tilt upcoming elections in their favor.

But this year, Ms. Hollis will be removed from the board, the result of a local election law signed by Gov. Brian Kemp, a Republican. Previously, election board members were selected by both political parties, county commissioners and the three biggest municipalities in Troup County. Now, the G.O.P.-controlled county commission has the sole authority to restructure the board and appoint all the new members.

Partisan election boards.

G.O.P. lawmakers have also stripped secretaries of state of their power, asserted more control over state election boards, made it easier to overturn election results, and pursued several partisan audits and inspections of 2020 results.

Republicans have introduced at least 216 bills in 41 states to give legislatures more power over elections officials, according to the States United Democracy Center, a new bipartisan organization that aims to protect democratic norms. Of those, 24 have been enacted into law across 14 states.

Removing power from one branch of government to ensure partisan control.

Republicans in Arizona have introduced a bill that would largely strip Katie Hobbs, the Democratic secretary of state, of her authority over election lawsuits, and then expire when she leaves office. And they have introduced another bill that would give the Legislature more power over setting the guidelines for election administration, a major task currently carried out by the secretary of state.

In Arizona they are not even trying to hide their contempt for democracy by writing into law a time limit based on the term of a single person. And in Arkansas,

The author of the legislation, State Representative Mark Lowery, a Republican from a suburb of Little Rock, said it was necessary to remove election power from the local authorities, who in Pulaski County are Democrats, because otherwise Republicans could not get a fair shake.

“Without this legislation, the only entity you could have referred impropriety to is the prosecuting attorney, who is a Democrat, and possibly not had anything done,” Mr. Lowery said in an interview. “This gives another level of investigative authority to a board that is commissioned by the state to oversee elections.”

Asked about last year’s election, Mr. Lowery said, “I do believe Donald Trump was elected president.”

Of course he does, but this is not about Donald Trump. It’s about the changing demographics and values in America. There is an assault against political norms from the right because culture is shifting beneath them and against them. They don’t favor an equitable and just world. This is not about meritocracy. It is aristocracy. It is also dangerous. People fight when they are threatened, but they fight like hell when they are backed into a corner and don’t see any options. Many of the politicians espousing views like those above feel their way of life is being challenged. Unfortunately, there are very few compelling ideas coming from the political right currently.

I have strong faith in America, but I worry for us. We talk about threats to democracy, like terrorism, communism, or Russia, but democracy does not fail from without, it fails from within.

Apple Private Relay is Tor for Safari

Apple’s upcoming operating systems include a new feature in Safari, Private Relay. The functionality is essentially the same as onion routing which you may know from the Tor Project. Bruce Schneier has a nice overview on his site. Of note:

Not available in China, of course — and also Belarus, Colombia, Egypt, Kazakhstan, Saudi Arabia, South Africa, Turkmenistan, Uganda, and the Philippines.

I’m glad Apple is building this into Safari. It is a useful feature that will help anonymize your internet traffic. Remember that if you login to a website your anonymity goes away immediately. As a global enterprise Apple has to make compromises in certain parts of the world. If anonymity is important for your life or well-being or if you are simply privacy conscious and travel to the places listed above I still recommend using Tor.

MailTrackerBlocker Sherlocked in macOS 12

This month Apple announced that starting with macOS 12 mail.app will block tracking pixels in emails by default. This is a great feature. It was possible to do this using 3rd party plugins as I posted before. Unfortunately, these apps have all been “sherlocked”. If you develop anything in the privacy space right now you can bet that Apple will make your idea part of the system soon.

Prusa Mini+ Review

I picked up 3D printing as a hobby during COVID last year and quickly became hooked. It has become a tool like a screwdriver. I use and abuse it. Every problem seems to have a printable solution. I also fell into a side job at the end of last year and with the economy picking up this year orders outstripped capacity. The Prusa Mini was well reviewed and received a + update at the end of last year. I ordered a kit and waited.

TL;DR

The Mini+ is an exceptional value. The kit, instructions, and part quality are what you would expect from Prusa, that is, second to none. I was doubtful that they could improve on the quality of the MK3S but this is a higher quality machine. Some will complain about the build volume but it’s more than sufficient for most hobby and professional parts particularly when you consider breaking parts into assemblies. This is a good investment for beginners and seasoned printers.

Pros

  • Great price point
  • Prusa quality
  • Integration with PrusaSlicer
  • Very stable
  • UI is intuitive

Cons

  • Cantilevered design is difficult to move around
  • Build volume is smaller than many entry level printers
  • Filament can be hard to remove from the bowden tube/filament sensor assembly
  • Routing of the LCD cable can lead to pinches and failures.

My Take

The Mini has a low price point but it is not a cheap printer. The build is sturdy and software features are on par with printers that are 3-4 times as expensive. Novices don’t have to worry about the tinker factor. This machine will work right out of the box. Those with experience can easily build a machine from the kit (Haribo included), test, calibrate, and print a top notch Benchy in 12 hours or less. All of this is also backed by Prusa’s exceptional customer service and solid history of updates.

One of the reasons that Prusa MK3S printers are easy to use is the PINDA system and mesh bed leveling. Coupled with a live Z-axis adjustment it is easy to dial in the first layer of a print. Beautiful first layers mean far less problems and far happier owners. The original Mini was not as reliable as the MK3S. It required more user intervention on the first layer and was susceptible to level drift due to thermal fluctuations. Mini+ has what Prusa markets as the SuperPINDA probe that alleviates these problems. I can’t speak for long term reliability, but I’ve printed non-stop for over a week and the first layer repeats perfectly for any given spool.

There are some small design changes on the Mini+ that are also coming to the MK3S+ via an upgrade. With the exception of new bearing clips these changes are probably imperceptible but they all add up to fix pain points associated with the original Mini. Time will tell if they were the right choices. The fit and finish of the machine is excellent. My feeling is that this machine will see less wear and tear on the bearings and belts than my MK3S.

Prusa has teased WiFi capability for the Mini and has shown us glimpses of PrusaConnect, their vision of a remote management system for one printer or an entire farm of printers. WiFi is not available and PrusaConnect is currently just a remote monitoring system. If you want to operate your Mini+ remotely you can rely on third party solutions. I use Octoprint and the setup is no different than for any other FFM/FDM printer. PrusaConnect has seen more development on the SLA front and given that Prusa has just released a nice update to their SLA machine I think they may have been putting their resources toward that system first. We will see.

Conclusion

The real question is, should I buy it? There are cheaper machines available. Many even have larger build volumes. Often you get what you pay for though. A lot of these machines require manual leveling. This is difficult, time consuming and error prone. The build quality is often lacking particularly with respect to electronics and wiring. Some are so poor that they are actually quite dangerous. There is no need to worry about this with Prusa. If you are a novice and want to get into 3D printing then this a solid entry level machine. At $349 USD for a kit and $399 for a semi-assembled printer the price is affordable. The only drawback I can see is that a direct drive printer is easier to handle if there are filament breaks or jams. I don’t expect to see this in the Prusa machine though. If you are more seasoned then this may still be a welcome addition to your farm. With some tuning I am printing faster and with better quality than on my MK3S. The Mini+ is a workhorse that can run round the clock and hold very nice tolerances. Given the price I’m sure this is not the last one I’ll buy.

MIT Creates Zoomable Lens Without Any Moving Parts

Extreme Tech reports on a recent proof of concept from MIT that allows a lens to focus without moving the optical elements.

The science of optics has revealed the scale and detail of the universe for centuries. With the right piece of glass, you can look at a distant galaxy or the wiggling flagella on a single bacteria. But lenses need to focus — they need to move. Engineers at MIT have developed a new type of “metalens” that can shift focus without any moving parts. This could change the way we build devices such as cameras and telescopes.

The metalens changes structure when heat is applied and it interacts with light differently in these different “phases”. Richard Feynman once said that there is always room at the bottom. We are only scratching the surface of what is possible with solid state devices and quantum phenomena. It will be interesting to watch this technology develop.