Archive for the ‘Geekery’ Category.

Muting and Unmuting Zoom Participants at School

I recently found this setting on Zoom for our school district and found it tremendously helpful! The host of a Zoom meeting can mute and unmute the participants in their Zoom classroom after changing a setting and getting permission from the participant. Here’s a video tutorial I made showing how to do it: https://youtu.be/j96BJcho_ec. Make sure to ask permission so the students don’t see this as an invasion of their privacy. Share this tip as you choose, some teachers will find it indispensable.
If you can’t find the “unmute” option in the menu, you probably need to upgrade your Zoom software. It’ll take just a minute: In the Zoom program, click on your face in the upper right corner of the window. Then click on “Check for Updates”.  Then do the instructions from the video above.
The unmute feature probably isn’t available if you are using a personal license of Zoom.

Ripping DVDs To Use On Plex

I only have one DVD drive in the house and no DVD drive connected to our new “smart” tv. So here’s how we watch DVD movies on the Smart TV.

First, set up Plex It’s a Windows program that let’s you serve videos around your house. They’ll also rent you videos and such. I leave the computer running all the time.

  • Use DVDDecrypter to rip a copy of the DVD onto my computer. I use the rip below and also save it since the DVD format with commentary and extras isn’t saved perfectly in the next few steps.
  • Sometimes DVDDecrypter craps out. When that happens, I try using MakeMKV to rip the DVD. Failing that, I try using VLC. Failing that, I get a copy from ThePirateBay.
  • Point MakeMKV at the rip and turn the DVD into several .mkv files. The big file (usually 1-6 gigabytes) is the movie and then there’s often extras like a Making-of and such.
  • Move the big file directly into my Plex movies folder
  • Use MKVToolNix GUI to merge all the other files together into one because I like having a “Movie” and a “Movie extras” file but having 5-10 “extras” files is just a cluttered mess.
  • Look at the created “extras” file and make sure it worked. I don’t know exactly why but some merges don’t work. 1/2 way through the merged video, the audio or picture will crap out. This might be because the merged files were in different formats or something. If it doesn’t work, I abandon the “extras”, I haven’t figured out how to fix that problem.
  • Some videos have trouble fast forwarding and rewinding on Plex, especially on my Visio TV. I found that if I transcode them into H.264 using Handbrake (mp4 format, Align A/V start (dunno if I need it but it doesn’t hurt)) I don’t have that problem any more. I’ve had this problem with some videos downloaded from the internet. H.265 makes the smallest files but Plex handles H.264 natively so it doesn’t have to pin the CPU on the server to transcode it on the fly. It takes 1-5 hours to transcode a movie in Handbrake, depending on your settings, so set up the Queue and run it overnight!

Notes on above:

  • The rip takes about an hour. The other steps take just 1-5 minutes total.
  • To use MKVToolNix GUI: drag the first file onto the Source Files area. Then grab the rest of the files and drag them there. It’ll ask how you want to add them, choose “Append to an existing source file”. Then push the “Start multiplexing” button at the bottom. It might throw an error and refuse to merge the files. This is because the files are, in some way, not the same type. Look in the error log. A common error is “The number of channels of the two audio tracks is different.” To fix that, I use Handbrake to transcode all the files, making sure to set the audio “mixdown” to “stereo”; that way, fancy Dolby 5.1 audio is pushed down to stereo. This doesn’t always fix the problem. I haven’t figured out all the fixes yet, sometimes I just bail on putting all the extras into one file.

 

How to Download Most Online Videos

If you need to download a video on Youtube or Vimeo or wherever, this process will often do it for you, fer free and without downloading some likely-spammy-scammy software.

The key is: most video online is HTML5. VLC can play any HTML5 video… and get you the link to download it. (via)

Using Wget to Download a Website

Wget is a great tool for downloading individual webpages or entire websites. View the Wget manual.

When the site is password protected, you might do the following to download the site:

  • Download Wget.exe for Windows (there is no installation)
  • Get the Cookies.txt Chrome extension
  • Log in to the site
  • Use the Cookies.txt extension to copy-paste the cookies into a file named cookies.txt in the same folder as wget.exe
  • Run a command that looks like this (maybe it’s overkill, but after banging on it for a while, this worked. So there):

wget –recursive –no-parent –timestamping=on –no-clobber –page-requisites –html-extension –convert-links –restrict-file-names=windows –no-parent –load-cookies cookies.txt -e robots=off -U mozilla “https://www.EXAMPLE.COM/WHATEVER/”

I have had a little trouble with the cookies not working correctly. I’m not sure yet if it’s the cookie expiring after a few minutes and not getting renewed or Wget somehow fetching too aggressively. I successfully fetched a site by refreshing the homepage in Chrome (maybe keeping the cookie valid) and fetching from below the top level.

Replacing the Battery on an Ensoniq KT-88 Electronic Keyboard

I replaced the battery on my Ensoniq KT-88 electronic keyboard today. It wasn’t hard. Took about 45 minutes of unscrewing, fiddling with connectors, and soldering. (actually, the keyboard is on long-term loan from a good friend :-) )

I bought the battery from Syntaur. Maybe I could have found it for a few dollars cheaper but it wasn’t expensive and I wanted to make sure it was a good battery and had the right tabs on it! These guys rock.

Here she is, ready to go
Take all the screws off of the flat back plate. I counted… umm, a lot. I counted 3 types of screws so keep them separate for reassembly.
Unhook all the connectors, plastic pins, and screws from the motherboard carefully. A flathead screwdriver helped with leverage
Bjonk, it’s on my workbench!
There’s the culprit. Multimeter said 0.0 volts.
I just snipped it off and…
… soldered the new battery in place!
3 volts, yay!
It powers up without any trouble :-)

After I was done replacing the battery, none of the controls worked! Argh! I did a factory reset thanks to the internet (local archive), to reset the Ensoniq KT-88 “PRESS EDIT/SEQUENCES (PRESETS). PRESS AND HOLD THE UPPER 9 BUTTON AND THEN PRESS THE LOWER 9.RELEASE BOTH AND PRESS YES AT THE PROMPT.”. That didn’t actually fix it. But I now find that if I turn it on and power cycle it once quickly (off for about 1/2 second) controls respond perfectly until I turn it off for a length of time. It’s finicky but it works! Hurray!

On Having 2 Monitors

I have 2 monitors on my laptop computer. It’s nice. Here’s info about my second monitor:

AOC 15.6″ USB powered monitor
ClickMonitorDDC (12-8-20 that link is broken now, see here)
Displaylink driver (12-8-20: not any more, see below)

I set up ClickMonitorDDC so I could change the brightness of both monitors easily. Info here. I also set it up to change the volume easily.

I had an, apparently common problem where sometimes the screen would restart repeatedly. To fix it, I disabled “USB Selective Suspend” and upgraded to the December 2019 Displaylink drivers. That fixed it. There’s more tips on fixing that problem here in case my fix doesn’t do it.

I bought 2 of those USB-powered monitors so I don’t have to drag it from home to work each day. That was nice.

 

Update 12-8-20: To get my second monitor to work well, I used to run the Displaylink drivers but with a recent update to… something… I don’t know… they weren’t working well but the Intel drivers started working. I used the Intel Driver & Support Assistant to automagically install and update the right drivers.

What is a Locating Sleeve on an Oscilloscope

I just got an oscilloscope and the manual mentioned “Locating Sleeve: Using locating sleeve could ensure the stability and reliability of the tip exposed to the test point.” Say what?

Here is what a locating sleeve is for. If you need to carefully touch just one point on a PCB, you can take off the tip of your probe off, that is the tip with the spring loaded hook, and then attach the locating sleeve. Now it will be easier to touch just what you are intending to.

How to Install The Google Play Store on Your Amazon Fire HD 8

These instructions work! Hurray! I tried a while back and it didn’t work.

This tip came from my friend Tim A. He added, “I found that it seemed to stop me downloading the apks directly, so I put them on the SD card and installed them from there.”

 

Quickly add the Google Play store to your new Amazon Fire 10HD

Cricket Wireless and Google Voice

If you use Cricket Wireless, you may have found, like me, that Cricket Visual Voicemail sucks. Here’s how to change to using Google Voice voicemail.

Step 1: Get free a Google Voice account with a new phone number

Step 2: Set up conditional call forwarding like so:

**004*[your google voice number]#

Step 3: Have someone call you and the call should be answered by your google voice. Rejoice in the non-suckyness!

You can disable this forwarding with #004#

You can read more about conditional call forwarding for GSM phones here

 

Update 11-6-19: On the Google Pixel 2, I was unable to use the **004* code. It threw an error. So I did what a few websites recommended: Put the SIM card into another phone, type in the code above, put the SIM card back in your phone. Done!

 

Why do I say the Cricket Visual Voicemail Android app sucks?

  • I have to push most buttons twice for it to work (sounds crazy? it is!)
  • When I start playing a voicemail, the first 3 seconds play and then it stops. Hitting play (twice) restarts it as long as I’ve waited the magically determined amount of time. It’s crazymaking like having a big piece of lint under one of my keys!
  • It often doesn’t transcribe my messages
  • I’ve had these exact same problems for 3 years and 2 phones

 

Sorry About The Spam

TL;DNR: I was getting 50,000 spam email bounces per day. I enabled SPF, DMARC, and DKIM. I made an email filter at Dreamhost to stop the email forwarding madness from Dreamhost to my Gmail account. Problem solved! (for now)

Tens of thousands of people have been getting spam claiming to be from Lee.org. (Update 8-4-18: HUNDREDS of thousands 🙁 ) First, I’m sorry about that! Second, it’s not actually coming from me. Third, I documented below how you too can stop spam from being spoofed from your domain.

I was alerted to this when I got 20,000 email bounces last week from a letter sent in my name. That one started:

From: Mr-Williams <lee@lee dat org>
Subject: Re: Your Outstanding Bill Payment notification
How are you doing today? I am Pleased to inform you that we have made arrangement with bank of America to release your payment sum of $10.3 Million dollars…

I realized that my (geekspeak alert!) SPF record was incomplete. So bad actors were able to pretend to be me and send zillions of spams in my name. I had incorrectly set my SPF record in my DNS to:
TXT v=spf1 include:netblocks.dreamhost.com
but it should have been set to:
TXT v=spf1 include:netblocks.dreamhost.com -all

Without the “-all”, SPF wasn’t working to stop spam in my name!

Here’s what one of the spam email headers looked like:

Authentication-Results: spf=neutral (sender IP is 201.162.82.32 (In Brazil, definitely not from my mail host!!!))
smtp.mailfrom=lee.org; hotmail.com; dkim=none (message not signed)
header.d=none;hotmail.com; dmarc=none action=none header.from=lee.org;
Received-SPF: Neutral (protection.outlook.com: 201.162.82.32 is neither
permitted nor denied by domain of lee.org)

MXToolbox is what keyed me in to what was going wrong. Thanks!

Other good tools are:
http://www.openspf.org/SPF_Record_Syntax
GSuite Toolbox Check MX
mxtoolbox.com
https://mxtoolbox.com/domain/lee.org/
And the whole mxtoolbox site

And thanks to Shehz for the helpful comment!


Update 8-3-18
I also added a DMARC record to my DNS
It’s a TXT record under lee.org that looks like so:
_dmarc TXT v=DMARC1; p=quarantine; ruf=mailto:[myDMARCemailaddress]@lee.org; rua=mailto:[myDMARCemailaddress]@lee.org; sp=n
one; ri=86400

So now email receivers know definitively what to do with spam coming to them from lee.org. And I get a report of when a bounce happens. I initially set p to “none” and got a few correct DMARC reports. Now it’s “quarantine” and in a little while I’ll set it to “reject”.


Update 8-3-18 #2
With DMARC enabled, I’m getting fifteen hundred reports a day telling me that spam “from” lee.org is being blocked. Ugh, sorry world! That tide is stopping now!

I got help with DMARC from these sites:

* https://dmarcian.com/
* https://dmarc.org/
* https://mxtoolbox.com/SuperTool.aspx?action=dmarc%3alee.org&run=toolpage


Update 8-22-18
I averaged 700 DMARC spam reports per day for the last 7 days.

Update 10-19-19 I got rid of the mailto: fields in my DMARC entry. I’m tired of getting kinda-pointless DMARC messages.


Update 10-18-18

Dreamhost shut off my email temporarily twice recently because the quantity of spams being forwarded from my Dreamhost lee.org account to my Gmail account were getting the better of them. Ugh. Here was the suggestion from Toby at Dreamhost:

SPF and DKIM records only help if the receiving server checks them. I would advise not to forward to gmail as this causes server load issues for everyone else on the server if you do run into further problems with this. You can configure your Gmail client to retrieve your email directly from Dreamhost’s server using POP3, and discontinue the use of your forwarder.

You’ll get all the benefits of Google SPAM filter as well, and this will be functionally equivalent to your current configuration. For more information on how to set up the Google side of things, please refer to the following article:

https://help.dreamhost.com/hc/en-us/articles/214870568-How-to-check-your-DreamHost-email-at-Google

Additionally you can setup filtering to filter out these spam message so
they don’t forward nor clog up your email box.

https://help.dreamhost.com/hc/en-us/articles/215030678-Custom-filters-How-to-enable-message-filters-on-an-email-address

I set up POP3 fetching and created some custom filters. I noticed that Gmail fetches about 200 emails per grab and it runs every 5 minutes or so. That means if I’m getting a lot of spam, Gmail won’t be able to keep up with fetching the mail! I just tested this and… OMG I opened the floodgates and started getting 250 email bounced PER MINUTE! It is no freaking wonder why Dreamhost turned off my email forwarding for a while!! Here’s a snapshot of Gmail and Dreamhost failing to keep up with the full force of spam with the spam floodgates wide open.

I deleted my spam folder with 1,500 emails and closed the floodgates by putting some filters in place at Dreamhost. But even 15 minutes later, old spams were still slowly trickling into the spam folder… Looking at the headers, it’s hard to tell if Dreamhost started choking/rate limiting or Gmail was choking/rate limiting.

I turned off POP3 mail fetch and left the mail filters in place. All is well now!

It was as simple as setting Dreamhost Panel | Mail | Message Filters | to “First, delete emails with [bad actor] in the body and then stop.”