Chris Bensen

Mastondon or Twitter

noreply@blogger.com (Unknown) — Thu, 10 Nov 2022 04:56:00 +0000

Mastodon https://mastodon.social/@chrisbensen or Twitter https://twitter.com/chrisbensen

How do I find my router's public IP Address from the command line?

noreply@blogger.com (Unknown) — Tue, 09 Nov 2021 15:00:00 +0000

dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com

@jpluimers commented on Twitter that he uses:

alias whatismyipv4='curl http://ipv4.whatismyip.akamai.com && echo'

Which is quite a bit shorter, I'll admit. However I think mine works in more situations, such as when http is blocked as @jpluimers mentions. I'm not worried about length because a. I don't have to do this very often and b. when I do I search my blog and copy-paste. If you do it often, maybe alias the dig command. But I will leave that as an exercise for the reader.

World's Largest 3D Printed Raspberry Pi Brick Computer

noreply@blogger.com (Unknown) — Sun, 14 Mar 2021 14:00:00 +0000

Make:projects

GraalVM on macOS Big Sur

noreply@blogger.com (Unknown) — Fri, 04 Dec 2020 15:00:00 +0000

Apparently Graal isn't registered or signed right for macOS Big Sur:

> graalvm-ce-java11-20.3.0/Contents/Home/bin/java —version

Produces the following:

To get around this, run the following:

> sudo xattr -r -d com.apple.quarantine graalvm-ce-java11-20.3.0

> graalvm-ce-java11-20.3.0/Contents/Home/bin/java --version

openjdk 11.0.9 2020-10-20

OpenJDK Runtime Environment GraalVM CE 20.3.0 (build 11.0.9+10-jvmci-20.3-b06)

OpenJDK 64-Bit Server VM GraalVM CE 20.3.0 (build 11.0.9+10-jvmci-20.3-b06, mixed mode, sharing)

All Raspberry Pi Super Computer Posts in One Spot

noreply@blogger.com (Unknown) — Tue, 17 Nov 2020 15:00:00 +0000

https://www.thingiverse.com/thing:3958586

https://www.thingiverse.com/thing:4652356

http://chrisbensen.blogspot.com/2019/06/very-large-raspberry-pi-cluster-part-i.html

http://chrisbensen.blogspot.com/2019/06/very-large-raspberry-pi-cluster-part-ii.html

http://chrisbensen.blogspot.com/2019/06/very-large-raspberry-pi-cluster-part-iii.html

http://chrisbensen.blogspot.com/2019/07/very-large-raspberry-pi-cluster-part-iv.html

http://chrisbensen.blogspot.com/2019/07/very-large-raspberry-pi-cluster-part-v.html

http://chrisbensen.blogspot.com/2019/07/very-large-raspberry-pi-cluster-part-vi.html

http://chrisbensen.blogspot.com/2019/09/bringing-pi-home.html

http://chrisbensen.blogspot.com/2019/11/raspberry-pi-super-computer-stl-files.html

http://chrisbensen.blogspot.com/2019/11/using-max-build-volume-of-ultimaker-3d.html

http://chrisbensen.blogspot.com/2019/12/get-mac-address-for-pi-cluster.html

http://chrisbensen.blogspot.com/2020/01/raspberry-pi-overlay-root-filesystem.html

http://chrisbensen.blogspot.com/2020/07/behind-scenes-building-worlds-largest.html

http://chrisbensen.blogspot.com/2020/11/parts-list-for-raspberry-pi-mini-super.html

git - make the history never exist

noreply@blogger.com (Unknown) — Wed, 11 Nov 2020 15:00:00 +0000

I committed something to my git repo that I didn't mean to. Always, I mean always create a .gitignore first and add everything that should be excluded. Modifying the history is super scary and dare I say, dangerous. I did a quick google search and ran across this which seems to have the best steps for doing the desired surgery.

https://stackoverflow.com/questions/10067848/remove-folder-and-its-contents-from-git-githubs-history/32886427#32886427

First run this to check the size:

git count-objects -vH

Just in case that link stops working I've pasted there relevant bits here:

# Make a fresh clone of YOUR_REPO
git clone YOUR_REPO
cd YOUR_REPO

# Create tracking branches of all branches
for remote in `git branch -r | grep -v /HEAD`; do git checkout --track $remote ; done

# Remove DIRECTORY_NAME from all commits, then remove the refs to the old commits
# (repeat these two commands for as many directories that you want to remove)
git filter-branch --index-filter 'git rm -rf --cached --ignore-unmatch DIRECTORY_NAME/' --prune-empty --tag-name-filter cat -- --all
git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d

# Ensure all old refs are fully removed
rm -Rf .git/logs .git/refs/original

# Perform a garbage collection to remove commits with no refs
git gc --prune=all --aggressive

# Force push all branches to overwrite their history
# (use with caution!)
git push origin --all --force
git push origin --tags --force

Lastly run this command to check the size again:

git count-objects -vH

It appears to have worked. I did have to reclone my repository which seemed a little odd but it worked.

Delete .DS_Store files on Mac

noreply@blogger.com (Unknown) — Tue, 10 Nov 2020 15:00:00 +0000

As with many things I post to my blog I post them here rather than keeping on some personal repository of information because I don't want to have to remember it every time (no matter how simple it might be) and other people might find it useful when searching around.

Have you ever needed to remove all the .DS_store files on your Mac from all subdirectories, I dunno, maybe from a git repository? If so here:

find . -name ".DS_Store" -print -exec rm {} \;

Parts List for Raspberry Pi Mini Super Computer

noreply@blogger.com (Unknown) — Thu, 05 Nov 2020 15:00:00 +0000

Here are the parts for the Raspberry Pi Mini Super Computer. A build video can be found here.

Name	Description	URL	Count	Price	Total
Ubiquiti Networks US-48 48-Port UniFi Managed Gigabit Switch with SFP BH #UBUS48 • MFR #US-48 4 reviews 2 Questions, 3 Answers		https://www.bhphotovideo.com/c/product/1267264-REG/ubiquiti_networks_us_48_48_port_unifi.html	2	359	718
Network Cloud Key	Ubiquiti Networks UniFi Cloud Key Gen2 B&H # UBUCKG2 MFR # UCK-G2	https://www.bhphotovideo.com/bnh/controller/home?O=productlist.jsp&A=details&Q=&sku=1426308&is=REG&fromDisList=y	1	179	179
Ubiquiti Networks Networks Unifi Security Gateway Pro (USG-PRO-4)		https://www.bhphotovideo.com/c/product/1224003-REG/ubiquiti_networks_usg_pro_4_enterprise_gateway_router.html	1	311.00	311
Lenovo		https://www.bhphotovideo.com/c/product/1447926-REG/lenovo_10vg000sus_m715q_tiny_amd_ryzen.html	2	$649.00	$1298.00
Raspberry Pi 3B+		https://www.adafruit.com/product/3775	84	$35.00	$2940.00
Pearstone Cat 6a Snagless Patch Cable (1', Blue)		https://www.bhphotovideo.com/c/product/1368134-REG/pearstone_cat6_a01bl_cat6_snagless_patch_cable.html	84	$1.99	$167.16
Pearstone Cat 6a Snagless Patch Cable (3’, Blue)		https://www.bhphotovideo.com/c/product/1368083-REG/pearstone_cat6_a03bl_cat6_snagless_patch_cable.html	6	$1.99	$11.94
StarTech.com 3 ft / 91cm Micro USB Cable - A to Right Angle Micro B - USB Type A - 90 Degree Micro-USB Type B (M) - Black (UUSBHAUB3RA)		https://www.amazon.com/gp/product/B001AR4NC8/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1	84	$3.00	$252.00
Security-01 2 Packs 80mm by 80mm by 25mm 8025 12V DC 0.20A Ball Bearing Brushless Cooling Fan 2pin AV-F8025MB UL CE		https://www.amazon.com/gp/product/B072QCTYJW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	42	$15.98	$671.16
USB Charging Station, 60 Ports USB Power Station		https://www.amazon.com/gp/product/B07MB12XZ4/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1	2		0
NP-05B Remote PDU, UL-STD TUV Listed, 5 Switchable Outlets. Manufactured and Supported in USA. Control Via Web, Telnet, USB Serial Port.		https://www.amazon.com/gp/product/B0039OZKPE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$229.00	$229.00
10 Pack AC 250V 10A IEC 320 C14 Panel Mount Plug Adapter Power Connector Socket Black Screw Mount 3 Pins Inlet Power Plug Socket By MXR		https://www.amazon.com/gp/product/B07DCXKNXQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$6.99	$6.99
20 Amp Commercial Grade Self Grounding Duplex Outlet, White		https://www.homedepot.com/p/Leviton-20-Amp-Commercial-Grade-Self-Grounding-Duplex-Outlet-White-CR020-W/301361601?mtc=Shopping-VF-F_D27E-G-D27E-27_2_WIRING_DEVICES-MULTI-NA-Feed-PLA-NA-NA-WIRING_DEVICES&cm_mmc=Shopping-VF-F_D27E-G-D27E-27_2_WIRING_DEVICES-MULTI-NA-Feed-PLA-NA-NA-WIRING_DEVICES-71700000033102358-58700003867202208-92700048704098216&gclid=Cj0KCQjwlN32BRCCARIsADZ-J4sX8I34COOeOObT54AuBh8-WH9bJEW56rMUTTd-6F6A_CWZAGu1hdMaAg4fEALw_wcB&gclsrc=aw.ds	1	$1.58	$1.58
ADJ Products AC POWER STRIP (PC-100A)		https://www.amazon.com/gp/product/B00KFZ98YO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$60.00	$60.00
Lenovo m715q		https://www.bhphotovideo.com/c/product/1447926-REG/lenovo_10vg000sus_m715q_tiny_amd_ryzen.html/?ap=y&ap=y&smp=y&smp=y&lsft=BI%3A514&gclid=Cj0KCQjwlN32BRCCARIsADZ-J4tcQ5N2xqLSAEzwLDfX2ZHTNgKxCieVyw98BsSOkuGtUyIclAF70E8aAvMeEALw_wcB	2	$500.00	$1000.00
UGREEN USB C Charger 18W PD 3.0 Type C Wall Charger Power Delivery for iPhone SE 11 Pro Max Xs Max XR X 8 Plus, AirPods Pro, iPad Pro, Google Pixel 3a XL, Samsung Galaxy S10+ S9+, LG V50 ThinQ G8	Needed to power cloud key	https://www.amazon.com/gp/product/B07R7K2QMW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$13.89	$13.89
XLX 50PCS 25Pair Mini Micro 2.54 2PIN Female and Male Connection Plug with Red Black Terminal Connector Wire Cable 200mm Compatible with JST XH	Connect to fans. You have to swap red and black or remember to connect red to black	https://www.amazon.com/gp/product/B076JFFDWN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$17.99	$17.99
Power supply for fans?
DisplayPort to HDMI, Benfei Gold-Plated DP Display Port to HDMI Adapter (Male to Female) Compatible for Lenovo Dell HP and Other Brand	Connect Lenovo to HDMI	https://www.amazon.com/gp/product/B017Q8ZVWK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	2	$9.99	$19.98
BATIGE HDMI Male to Female Car Mount Flush Extension Cable Truck Boat Motorcycle Dashboard Flush Mount with Mounting Panel - 3ft		https://www.amazon.com/gp/product/B01LX1FQPE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	2	$9.45	$18.90
VELCRO Brand ONE-WRAP Roll Black \| 30 Ft x 1-1/2 In \| Reusable Self-Gripping Hook and Loop Tape \| Cut Straps to Bundle Tie Materials and Tools in Garage Shed or Worksite		https://www.amazon.com/gp/product/B00404ULFQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	$20.00	$20.00
GOWOS (5 Pack) Cat6 Shielded RJ45 Panel Mount Industrial Bulkhead - Female to Female Feed Thru Coupler		https://www.amazon.com/gp/product/B07PRDVZ5X/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1	1	$57.03	$57.03
Neutrik NE8FDP etherCON RJ-45 Feedthrough Chassis Connector		https://www.amazon.com/gp/product/B002BER402/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	2	$8.71	$17.42
Gigabit + PoE Adapter (L6-NETPOE)		https://redpark.myshopify.com/products/gigabit-ethernet-poe-adapter-l6-netpoe?_pos=1&_sid=d0dccef3e&_ss=r	1	99	99
USB Micro B Cable for Lightning 400mm (L90-B-4)		https://redpark.myshopify.com/products/usb-micro-b-cable-for-lightning-l90-b-40?_pos=4&_sid=a7fe65e2c&_ss=r	1	29.00	29
SR Mini Keyboard Wired Thin Light 78 Keys USB Multimedia Small for Pc Computer Laptop		https://www.amazon.com/gp/product/B01IQL2VCE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	1	12.99	12.99
Neutrik NE8FDP etherCON RJ-45 Feedthrough Chassis Connector		https://www.amazon.com/gp/product/B002BER402/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1	2	8.71	17.42
Seismic Audio - SA-ET10-10 Foot CAT6 Ethercon Compatible RJ45 Pro Audio Patch Cable - Pro Series OFC for Recording, Stage, Studio use		https://www.amazon.com/dp/B07MCYS74X/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B07MCYS74X&pd_rd_w=xd6L9&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=eTMA3&pf_rd_r=K8R6X4J5Y7Z0728XY4EY&pd_rd_r=1bdfcc85-8cc3-48cd-856a-c4fc7c79ac54&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExS1dVQVMzS1VGVEVOJmVuY3J5cHRlZElkPUEwMTgyMDkzMzczMkhVTDVGT0VGRCZlbmNyeXB0ZWRBZElkPUExMDE0NTkyMVNXOVpRQUdOV0o2NiZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=	1	19.99	19.99
Pelican Air 1615 Case with Foam (Yellow)	With Foam	https://www.amazon.com/gp/product/B07JHTXF3X/ref=ppx_yo_dt_b_asin_title_o08_s01?ie=UTF8&psc=1	1	325.77	325.77
Ceptics 12Pcs International Travel Worldwide Grounded Universal Plug Adapter Set - Charge Your Devices from Anywhere in The World		https://www.amazon.com/gp/product/B01DJEBLQU/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1	1	13.85	13.85

Three Important Things to Work From Home

noreply@blogger.com (Unknown) — Thu, 27 Aug 2020 14:00:00 +0000

As most people around the world with a desk job have been working from home for the better part of the last 6 months, and as I sit here displaced because of the California fires without my normalcy, I just wanted to write about a few things that I find important working from home, but the same can apply to working from an office as well:

1. A good headset

I have tried a lot of headsets. There are two that I really like

Sennheiser GAME ZERO Gaming Headset

Apple AirPods

Both of these have noise cancelling and just work. Don't bother with the AirPod Pro noise cancelling, I'm sure they're nice but they are super expensive, and if you don't get the wireless charging case then you can get AirPods for around $120 which is still expensive but they really work great. Other similar headphones are out and I haven't tried all of them but considering I'd probably try 2-3 at half the price then surpassing the price of the AirPods and the AirPods work great I just go with it.

2. A good desk adjusted ergonomic desk that is adjusted properly

Powered Up Down Desk

4-Legged Powered Up Down Desk

Buy a set of these legs and an IKEA butcher block counter top and you have yourself one awesome desk.

3. Exercise

Daily minimum 30 minutes of hard exercise. Find a routine and stick to it. Burpies in a tight space are great but get the heart rate up there.

Evacuated from the Fires in Santa Cruz - Tried to Rescue the Raspberry Pi Mini Super Computer

noreply@blogger.com (Unknown) — Wed, 26 Aug 2020 14:41:00 +0000

We had to evacuate our home because of the fires in Santa Cruz California. Trying to find some humor in a very difficult situation.

Upgrade to macOS Catalina broke the Arduino IDE

noreply@blogger.com (Unknown) — Thu, 30 Jul 2020 14:00:00 +0000

Everything was working fine and then I upgraded to macOS Catalina. The Arduino IDE version 1.8.12 just wouldn't start. Then I ran from terminal and looked at the actually error.

./Arduino
Set log4j store directory /Users/cbensen/Library/Arduino15
2020-07-30 08:39:47.311 Arduino[73800:11442574] name is : .SFNS-Regular
2020-07-30 08:39:47.311 Arduino[73800:11442574] family is : .AppleSystemUIFont
2020-07-30 08:39:47.311 Arduino[73800:11442574] name is : .SFNS-Bold
2020-07-30 08:39:47.311 Arduino[73800:11442574] family is : .AppleSystemUIFont
2020-07-30 08:39:47.312 Arduino[73800:11442574] name is : .SFNSMono-Regular
2020-07-30 08:39:47.312 Arduino[73800:11442574] family is : .SF NS Mono
2020-07-30 08:39:47.706 Arduino[73800:11442574] CoreText note: Client requested name ".SFNS-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.706 Arduino[73800:11442574] CoreText note: Set a breakpoint on CTFontLogSystemFontNameRequest to debug.
2020-07-30 08:39:47.706 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNS-Regular
2020-07-30 08:39:47.707 Arduino[73800:11442574] CoreText note: Client requested name ".SFNS-Bold", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.707 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNS-Bold
2020-07-30 08:39:47.707 Arduino[73800:11442574] CoreText note: Client requested name ".SFNSMono-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.707 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNSMono-Regular
2020-07-30 08:39:47.710 Arduino[73800:11442574] CoreText note: Client requested name ".SFNSMono-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.710 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNSMono-Regular
2020-07-30 08:39:47.710 Arduino[73800:11442574] CoreText note: Client requested name ".SFNSMono-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.710 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNSMono-Regular
2020-07-30 08:39:47.713 Arduino[73800:11442574] CoreText note: Client requested name ".SFNS-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.713 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNS-Regular
2020-07-30 08:39:47.713 Arduino[73800:11442574] CoreText note: Client requested name ".SFNS-Bold", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2020-07-30 08:39:47.713 Arduino[73800:11442574] needed to substitute Lucida Grande for: .SFNS-Bold
java.lang.NullPointerException
at cc.arduino.contributions.packages.ContributionsIndexer.parseIndex(ContributionsIndexer.java:134)
at processing.app.BaseNoGui.initPackages(BaseNoGui.java:483)
at processing.app.Base.<init>(Base.java:273)
at processing.app.Base.main(Base.java:150)

After some digging around, trying a few things I came across this article https://github.com/arduino/Arduino/issues/9828 and I decided to live life on the edge and try the hourly build! And that did it. So there's an issue and it apparently is known and has been fixed.

Running Out of Memory with SQL Developer

noreply@blogger.com (Unknown) — Thu, 23 Jul 2020 14:00:00 +0000

Previously I wrote about getting SQL Developer to work, well, just work here. It just doesn't work as downloaded and is still a very useful tool when connecting to databases. I recently ran into another issue, which is out of memory problems. It's rather easy to fix but I spent all day tracking down in the boot scripts for how. So here's how (even if all I'm doing is documenting it for my future self):

1. Open the file in your favorite text editor:

/Applications/SQLDeveloper.app/Contents/Resources/sqldeveloper/ide/bin/ide.conf

2. Search for the line:

AddVMOption -Xmx800M

3. Change it to more, a lot more! I just added a couple zeros and I'm all good:

AddVMOption -Xmx80000M

So there you have it.

Behind the Scenes - Building the World's Largest Raspberry Pi Cluster

noreply@blogger.com (Unknown) — Wed, 01 Jul 2020 14:00:00 +0000

I thought I'd published this already. Well, better late than never. Here is a look behind the scenes of building this amazing piece of equipment.

https://youtu.be/KbVcRQQ9PNw

Java Preview Features

noreply@blogger.com (Unknown) — Mon, 04 May 2020 14:00:00 +0000

Today I went to write some Java and test out the preview features. It wasn't as easy to use them as I thought it'd be. I normally use Netbeans. Don't ask. I use a lot of different IDEs but quickly realized yeah, JDK 14 and the preview features don't work in 11.3 at all. So here's how to get it working in InntelliJ IDEA.

1. Go to File and choose Project Stucture

2. From here set the "Project language level" to 14 so you can write some records and text blocks.

Viola!

3D Printed Face Shield

noreply@blogger.com (Unknown) — Fri, 17 Apr 2020 00:00:00 +0000

https://www.thingiverse.com/thing:4292328

I uploaded a quick easy to print 3D printed face shield. This is based off the model by:

https://3dverkstan.se/protective-visor/

I have included both the STL and the Fusion 360 files.

I solved three problems with the original design:

1. Healthworkers didn't like the curls at the end since it conflicted with face mask straps and headbands so now the ends are straight.

2. I changed it to use a standard 3 hole punch. It doesn't attached to as many places but it isn't a problem because of the other fixes.

3. Each of the three visor attachment nubs is notched so the plastic goes over easier. This also solved the problem where the visor plastic would tear and fall off.

Now some hospitals will only accept face shields that come up over the head. This could be easily modified but would require a laser cutter or had cutting plus additional material, or extra time 3D printing. Many hospitals will accept this design and they are far faster to produce. So I suggest testing it out.

SQL Developer on Mac

noreply@blogger.com (Unknown) — Wed, 15 Apr 2020 14:00:00 +0000

I'm doing a little Autonomous Database project so I downloaded SQL Developer for Mac. When I run it I get the error:

SQL Developer requires a minimum of Java 8.
Java 8 can be downloaded from:
http://www.oracle.com/technetwork/java/javase/downloads/

Fortunately this is really easy to fix. I will file a bug so you don't have to make these changes but here's how to fix it.

1. Right click on SQL Developer in the dock and choose Options | Show in Finder
2. Right click on SQLDeveloper.app and choose "Show Package Contents"
3. Double click on Contents and then MacOS
4. Go to http://www.oracle.com/technetwork/java/javase/downloads/ and download JDK 1.8 JRE
5. Unzip it and copy the directory into the MacOS directory
6. Open sqldeveloper.sh in any text editor. I commented out everything in the file and pasted in the following:

export PATH=/Applications/SQLDeveloper.app/Contents/MacOS/jre1.8.0_251.jre/Contents/Home/bin:$PATH
export JAVA_HOME=/Applications/SQLDeveloper.app/Contents/MacOS/jre1.8.0_251.jre/Contents/Home

/Applications/SQLDeveloper.app/Contents/Resources/sqldeveloper/sqldeveloper/bin/sqldeveloper

so now sqldeveloper.sh looks like this:

#!/bin/bash

# TMP_PATH=`/usr/libexec/java_home -F -v 1.8`
# if [ -z "$TMP_PATH" ] ; then
# TMP_PATH=`/usr/libexec/java_home -F -v 9`
# #TMP_PATH='/Applications/SQLDeveloper.app/Contents/MacOS/jre-9.0.4.jre/Contents/Home'
# if [ -z "$TMP_PATH" ] ; then
# osascript -e 'tell app "System Events" to display dialog "SQL Developer requires a minimum of Java 8. \nJava 8 can be downloaded from:\n http://www.oracle.com/technetwork/java/javase/downloads/"'
# exit 1
# fi
# fi
#
# export JAVA_HOME=$TMP_PATH
#
# if [[ -f $HOME/.sqldeveloper/19.1.0/env.sh ]];
# then
# source "$HOME/.sqldeveloper/19.1.0/env.sh" >> /dev/null
# elif [[ -f $HOME/.sqldeveloper/env.sh ]];
# then
# source "$HOME/.sqldeveloper/env.sh" >> /dev/null
# fi
#
#
# here="${0%/*}"
# cd "${here}"
# cd ../Resources/sqldeveloper/sqldeveloper/bin
# bash ./sqldeveloper >>/dev/null

export PATH=/Applications/SQLDeveloper.app/Contents/MacOS/jre1.8.0_251.jre/Contents/Home/bin:$PATH
export JAVA_HOME=/Applications/SQLDeveloper.app/Contents/MacOS/jre1.8.0_251.jre/Contents/Home

/Applications/SQLDeveloper.app/Contents/Resources/sqldeveloper/sqldeveloper/bin/sqldeveloper

7. Save sqldeveloper.sh

Now run it and you should get the splash screen.

I actually worked on the core product that SQL Developer uses and built that splash screen, the fancy progress bar graphics and all the loading code of the plugins and migration system.

Fusion 360 On Mac

noreply@blogger.com (Unknown) — Mon, 10 Feb 2020 15:00:00 +0000

For the last year I've been using Fusion 360. Solidworks is too expensive for what I do, I haven't really liked Rhino or ViaCad, OpensCAD or FreeCAD. For the most part it works pretty good. There is however one problem I constantly encounter and that is the auto update mechanism leaves a lot to be desired. Chrome does this extremely well and I wish Autodesk would replicate their excellent system because at least once a month the Fusion 360 app either changes location in my dock or disappears completely. The disappearing completely is the biggest problem because then I have to go searching for it. Usually it lives here:

/users/<username>/library/application support/autodesk/webdeploy/production/Autodesk Fusion 360.app

So hopefully this saves someone some time.

Raspberry Pi Overlay Root Filesystem

noreply@blogger.com (Unknown) — Mon, 27 Jan 2020 15:00:00 +0000

I copied this from https://yagrebu.net/unix/rpi-overlay.md so I don't loose it. I have done a lot of network booting and overlay file system work this last year and these are the best directions for overlay file system and don't want to loose them. I will rewrite them to include my own subtle changes at some point, and publish network booting and network booting + overlay file system (which is a total crazy mess with no directions).

Raspberry Pi Overlay Root Filesystem

This document describes a method to protect the root filesystem from writes while still allowing all applications to function as normal while writing to a temporary Overlay filesystem. Figuring this out would have been impossible for me without this excellent post by ejolson on the RPI.org forums.

For my installation I used a RPI 3 and the latest Raspbian Stretch Lite image (2017-11-29). I do not know if these instructions will work without modification on earlier RPI hardware.

Note: When the overlay filesystem is in place your RPI will function as usual, but any data generated after startup is only saved in RAM and will be lost upon reboot.

Let's Begin

First we need to create a initramfs image that contains the overlay module and a boot script to mount our root partition with the overlay. (All this could of course be compiled into the kernel image, but initramfs-tools(8) is an easier way to learn about the early init-process.)

echo overlay >>/etc/initramfs-tools/modules

Place the following boot script in /etc/initramfs-tools/scripts/overlay (download):

# Local filesystem mounting                     -*- shell-script -*-

#
# This script overrides local_mount_root() in /scripts/local
# and mounts root as a read-only filesystem with a temporary (rw)
# overlay filesystem.
#

. /scripts/local

local_mount_root()
{
        local_top
        local_device_setup "${ROOT}" "root file system"
        ROOT="${DEV}"

        # Get the root filesystem type if not set
        if [ -z "${ROOTFSTYPE}" ]; then
                FSTYPE=$(get_fstype "${ROOT}")
        else
                FSTYPE=${ROOTFSTYPE}
        fi

        local_premount

        # CHANGES TO THE ORIGINAL FUNCTION BEGIN HERE
        # N.B. this code still lacks error checking

        modprobe ${FSTYPE}
        checkfs ${ROOT} root "${FSTYPE}"

        # Create directories for root and the overlay
        mkdir /lower /upper

        # Mount read-only root to /lower
        if [ "${FSTYPE}" != "unknown" ]; then
                mount -r -t ${FSTYPE} ${ROOTFLAGS} ${ROOT} /lower
        else
                mount -r ${ROOTFLAGS} ${ROOT} /lower
        fi

        modprobe overlay

        # Mount a tmpfs for the overlay in /upper
        mount -t tmpfs tmpfs /upper
        mkdir /upper/data /upper/work

        # Mount the final overlay-root in $rootmnt
        mount -t overlay \
            -olowerdir=/lower,upperdir=/upper/data,workdir=/upper/work \
            overlay ${rootmnt}
}

Create the initramfs image:

update-initramfs -c -k $(uname -r)

It will be placed in /boot/initrd.img<kernel_version> - you can rename it to match your kernel file if you want.

Add the following to /boot/config.txt - where initrd7.img is the initramfs image you created in the previous step:

kernel=kernel7.img
initramfs initrd7.img

And finally, add boot=overlay to the beginning of /boot/cmdline.txt.

This should do it. Reboot and keep your fingers crossed.

Kernel Panic

If the OS doesn't come back up, there is probably a typo somewhere, or you missed something.

You can remove boot=overlay from cmdline.txt to boot as normal.

A serial connection can be really handy when trying to troubleshoot the startup process. USB TTL console cables are dirt cheap, just make sure you get one that outputs 3.3V on the TX line so that you don't fry your RPI. Use screen(1)'s buffer to scroll back and try to figure out where it went wrong.

The documentation is also quite good. Read the man page for initramfs-tools(8) and the default boot scripts themselves:

less /usr/share/initramfs-tools/init
less /usr/share/initramfs-tools/scripts/local

Finishing Touches

Read-Only /boot

The /boot filesystem is still mounted rw. You can protect it as well by adding ro to the boot partitions mount options in /etc/fstab:

PARTUUID=72a9e9a9-01   /boot   vfat   defaults,ro   0   2

overctl

Since I would be updating the filesystem on my RPI regularly, I wanted a secure way to enable and disable the overlay. overctl has the following features:

Usage: overctl [-h|-r|-s|-t|-w]
   -h, --help     This message
   -r, --ro       Set read-only root with overlay fs
   -s, --status   Show current state
   -t, --toggle   Toggle between -r and -w
   -w, --rw       Set read-write root

Place the script in /usr/local/sbin and mark the file as executable. You will also need to create the following files containing the cmdline.txt options that you wish to toggle between:

/boot/cmdline.txt.orig
/boot/cmdline.txt.overlay

motd(5)

I figured I could use a reminder of which state the RPI is in. So I cobbled together this motd(5) script:

#!/bin/sh

str=$(mount | grep ' on / ')

if echo $str | grep -q 'overlay'; then
        printf "\n------ INFO: / MOUNTED WITH OVERLAY ------\n\n"
elif echo $str | grep -q 'rw'; then
        printf "\n++++++ INFO: / MOUNTED READ-WRITE ++++++\n\n"
else
        printf "\n!!!!!! WARNING: / UNKNOWN STATE !!!!!!\n\n"
fi

Place the code above in /etc/update-motd.d/80-overlay and make sure the file is executable.

Sony vs Canon: DSLR and Mirrorless

noreply@blogger.com (Unknown) — Thu, 09 Jan 2020 05:12:00 +0000

I had the Sony A9 and AIII and just couldn't use them because they are way too small for my hands. I think there has been so much attention on mirrorless, as well as marketing money to influencers on YouTubers which makes it seem like everyone is using Sony. I get it, mirrorless has it's place, and there are some great features. there's also some terrible features. I currently use a number of Canon DSLR cameras including the Canon EOS R. The R isn't my favorite camera, but it has grown on me. Anytime I reach for a camera, certainly for traveling, that is what I bring 90% of the time. The R and a Canon 7GX MII has been with me to 4 continents over the last year and I honestly wouldn't trade them for any Sony, despite having access to them. So here is my list of pluses and minuses:

- Blackout: The A9 has no blackout, all other mirrorless cameras have way too much blackout in my opinion. Canon R blackout is better than any Sony other than A9 but impossible to oh take photos of whales because they move too fast. Any DSLR such as Canon 5D MIV work fine for sports and wildlife photography, I just don't get the complaining of DSLR blackout. A DSLR instantly refreshes, where a mirrorless displays the previous image for way way too long and then refreshes. Only the A9 is usable for any wildlife or sports photography period.

- In body image stabilization (IBIS) I really don't understand why everyone wants IBIS. IBIS actually is a detractor if you want a seriously durable camera because the sensor shakes around.

- Smaller bodies are good for small hands, but not good for big hands. I have tried every battery grip available for the A series and they just don't work. The new body design is better, but not even close to a Canon or Nikon. Also the grip is shallow enough and the lens release is at the base of the body so when I grab the camera I've released the lens more than a few times.

- Sony can't handle water. If a Sony looks at water it stops working. Where I have dropped my 1D in river water and they keep working.

- Sony has no service support. When a camera needs servicing Sony suggest throwing it away and buying a new one. Canon has CPS, which is awesome if you need a camera serviced. Absolutely ridiculous Sony. No professional can depend on a Sony because of this.

- Shake a Sony camera and it makes noise. Strange.

- Love Sony A9 silent shooting, amazing for Wedding photography. Absolutely a game changer.

- I like the flip out LCDs on Canon better than Sony. Also the touchscreen. The menu system on Canon is way better too. The video codec is a little better on Sony.

- Canon color science is the best there is. Nikon is actually really great too. Hasselblad is pretty awesome too. Sony, not so much, every photo and video needs to be adjusted to look good. But Nikon video is lacking.

- Weight. Anyone that tells me that a Sony weighs less is crazy. Put a comparable lens on both cameras and compare the weight, they are basically the same and actually the Sony weighs more, just with a tiny camera in your hands. If you put a super small lens on a Sony then you have a weight savings, but meh. Now size is a bit smaller for traveling which is nice. But go for a micro 4/3 if size is a real issue.

- What is really nice about mirrorless is there's a shutter release button for photos and a record button for video. You don't have to switch between modes and remember do I look through the eyepiece or the rear screen.

- Lastly, all camera's do their best autofocus in good light. However, mirrorless cameras have poor autofocus anytime the light is anything less than good. The reason for this is what you see is what you get, but that is also what you autofocus from, where a DSLR will flip the mirror down and open up the lens aperture, evaluate then flip everything back to take the photo. This can take time, but 16 FPS for the pro series and 5FPS for the low end is pretty darn good.

Get MAC Address for a Pi Cluster

noreply@blogger.com (Unknown) — Fri, 20 Dec 2019 15:00:00 +0000

There are a lot of ways to get the MAC address for a Raspberry Pi. For the Super Pi there were a lot of Pi, 1050 to be specific (two of them are dead on arrival and we disabled 24 of them to get the exact number we wanted, 1024), we looked at the DHCP log files. Roy and Mike spent a few days doing this. Think about it, if you spend one minute times 1050, that's 17.5 hours! I'm surprised they didn't go crazy but they seemed to be having fun. For the Mini Super Pi, I need to know the order.

At this point I'm going to digress a little. When building a large Raspberry Pi cluster at some point it's worth network booting. I'd say after 8 the cost of network booting is worth it. Just the time and expense of buying and cloning eight network cards. Network booting a Pi isn't terribly difficult, it's doing it consistently with a lot of them that's the problem. The netboot on a Pi times out after a short period of time, it isn't implemented 100% to spec, I could go on but these are things you can find out with some research. Although it's buried so if people want me to document these issues let me know in the comments. If there are any problems netbooting the Pi can be dead in a big cluster with no way to reboot it except reboot the entire thing. It helps to have a static IP address. Best way of doing this is by using DHCP (yeah, that's confusing) but map the MAC address to an IP address. Oh, also if you have enough Raspberry Pi, the MAC address may not be unique. We have two Pi with the same MAC addresses. Most clusters won't run into this. Also, network booting while not difficult requires the use of overlay file system. The problem comes when combining the two which is rather difficult. I got overlay file system working. Roy merged netboot and overlay and Vijay did this with Oracle Linux. There are a few other options netboot and redirect all writes to separate files and hope you got all them, create an NFS mount for each Pi (yeah, no). The only downside to netboot + overlay file system is you can't run Docker, which means you can't run K8 because Docker uses overlay and you can't use overlay on top of overlay.

OK, back to the reason for this blog post. My new system for obtaining the MAC address is as follows:

1. Install Raspbian on an SD card. I used belenaEtcher on Mac just because it's easy.
2. Copy the following Python script to the Pi and call it pimac.py

import socket

import time

import threading

import datetime

import uuid

import random

# This is needed so we get a network interface

time.sleep(20)

# Global variables

MacAddress = hex(uuid.getnode())

print(MacAddress)

print(type(MacAddress))

if MacAddress.endswith('L'):

    MacAddress = MacAddress[:-1]

    print(MacAddress)

client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP

client.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

client.bind(("", 2222))

server = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)

server.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

server.settimeout(0.2)

server.bind(("", 3333))

hostname = socket.gethostname()    

IPAddr = socket.gethostbyname(hostname)    

print("Your Computer Name is:" + hostname)    

print("Your Computer IP Address is:" + IPAddr)

def SendMessage(port, message):

    data = message

    endodeddata = data.encode()

    server.sendto(endodeddata, ('<broadcast>', port))

    print("message sent!" + data)

while True:

    SendMessage(3333, MacAddress)

    time.sleep(2)

3. Create a cron job:

sudo crontab -e

4. Add this line to the end of the file:

@reboot python /home/pi/pimac.py &

5. Copy the following Python script to your desktop and run it. I'm running it in Visual Studio Code.

import datetime

import os

import signal

import socket

import threading

import time

import re

import uuid

if os.name == 'nt':

    signal.signal(signal.SIGINT, signal.SIG_DFL)

server = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)

server.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

hostname = socket.gethostname()

IPAddr = socket.gethostbyname(hostname)

print("Your Computer Name is: {0}\n".format(hostname))

print("Your Computer IP Address is: {0}\n".format(IPAddr))

def waitForPosts():

  print('Ready')

addresses = {}

class Listen(threading.Thread):

    def __init__(self, port):

        threading.Thread.__init__(self)

        self.port = port

        self.UIDCount = 0

    def run(self):

        client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP

        client.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

        client.bind(("", self.port))

        while True:

            data, addr = client.recvfrom(1024)

            mac = data

            if mac not in addresses:

                addresses[mac] = mac

                val = mac.decode()

                print (':'.join(re.findall('..', '%012x' % int(val, 16)))) 

publish_thread = Listen(3333)

publish_thread.start()

waitForPosts()

Note: If you decide you want to remove the dictionary in the code above to allow duplicate MAC addresses to print out, which his a great debugging tool and since UDP is not guaranteed is a perfectly fine way to go, then you might want to remove duplicates. To do this in Visual Studio Code this is one way I found to do it:

Control+F
Toggle "Replace mode"
Toggle "Use Regular Expression" (the icon with the .* symbol)
In the search field, type ((^[^\S$]*?(?=\S)(?:.*)+$)[\S\s]*?)^\2$(?:\n)?
In the "replace with" field, type $1
Click ("Replace All").

6. So now insert the SD card, plug the Pi into network, and power and wait. The output on your desktop will be a list of your MAC addresses in a known order and it is easy to know if one is dead and which one.

Shopify Payment System

noreply@blogger.com (Unknown) — Tue, 17 Dec 2019 15:00:00 +0000

It's a long story, but I have been dealing with an issue with Shopify for well over a year now. Many websites use them as their Payment system behind their merchant account. And they are very convenient, if one knew what they were getting into. Unfortunately there is absolutely zero disclosure on any of the websites that use it how this will work, how to edit your stored information or how to delete the data they stored. This is a direct breach of the GDPR, Informatique et Libertés as well as the new California data privacy law CCPA.

So with about a year of working with all of the merchants and Shopify support, I finally can report there is a way to opt out of Shopify:

https://pay.shopify.com/optout

Sparkfun MP3 Shield

noreply@blogger.com (Unknown) — Mon, 09 Dec 2019 23:21:00 +0000

SparkFun MP3 Player Shield

I have used a lot of these MP3 player shields in projects. They are super awesome and super simple to use, but I figured a small writeup was worthwhile as there are some details that aren't in the official documentation as well as some tips I have when using the shield.

The MP3 shield uses just about every pin on the Arduino. The documentation states you can use D5, D10 and A0-A5. However, I have found that for some reason when using the shield I have found neither D5 nor D10 to be usable. So typically what I do is setup a software serial using two of the analog pins:

#include <SPI.h>
#include <SdFat.h>
#include <SFEMP3Shield.h>
#include <SoftwareSerial.h>

SdFat sd;
SFEMP3Shield MP3player;

SoftwareSerial input(A0, A1); // RX, TX

void setup() {
Serial.begin(115200);

input.begin(9600);
input.flush();

if(!sd.begin(9, SPI_HALF_SPEED)) {
sd.initErrorHalt();
}

if (!sd.chdir("/")) {
sd.errorHalt("sd.chdir");
}

uint8_t result = MP3player.begin();

if(result != 0) // check result, see readme for error codes.
{
Serial.println("error");
Serial.print(F("Error code: "));
Serial.print(result);
}

// Loudest volume for left and right
MP3player.setVolume(0, 0);

Serial.println("Ready");
}

void loop() {
if (input.available()) {
Serial.println("reading");
String action = readFromSerial();
Serial.println(action);
input.flush();

if (action == "play") {
Serial.println("Playing");
uint8_t result = MP3player.playMP3("awesome.mp3");
delay(3000);
Serial.println("Ready again");
}
}
}

String readFromSerial() {
static char buffer[80];
if (readline(input.read(), buffer, 80) > 0)
{
Serial.println(buffer);
}
return buffer;
}

int readline(int readch, char *buffer, int len)
{
static int pos = 0;
int rpos;

if (readch > 0) {
switch (readch) {
case '\n': // Ignore new-lines
break;
case '\r': // Return on CR
rpos = pos;
pos = 0; // Reset position index ready for next time
return rpos;
default:
if (pos < len-1) {
buffer[pos++] = readch;
buffer[pos] = 0;
}
}
}
// No end of line has been found, so return -1.
return -1;
}

Using Max Build Volume of Ultimaker 3D Printer

noreply@blogger.com (Unknown) — Mon, 18 Nov 2019 15:00:00 +0000

Sometimes you have to print at the max build volume of your 3D printer. You'll get the error: "does not fit build volume". I have an Ultimaker and the easiest slicer to use is Cura. And sometimes I want the full build volume of 330 x 240 x 300 mm. If you set the "skirt link count" to zero, it won't print the line around the part so you can get the full x and/or y. As you may know the reason for the skirt is so that the printer gets a consistent extrusion of the filament, but I you need the full bed size, then you need the full bed size. Also turn off brim and set build plate adhesion to "none". Lastly set "travel avoid distance" to 0. Do it in that order for best results.

Raspberry Pi Super Computer STL Files Published on Thingiverse

noreply@blogger.com (Unknown) — Tue, 05 Nov 2019 15:00:00 +0000

Finally. I'm sorry it took so long. Here it is, the files to print your very own 2U rack mountable Raspberry Pi holder for 21 Raspberry Pi 3B+. Let me know if you have any questions or problems. Just because we made over 50 of these, doesn't mean it's easy.

https://www.thingiverse.com/thing:3958586

Bringing Pi Home

noreply@blogger.com (Unknown) — Mon, 02 Sep 2019 14:00:00 +0000