Just a QR Code

Every once in a while you need to generate a QR code.  You type "qr" into your address bar and hope your history still has something useful, but when it doesn't, you go ahead and google it.  Reviewing the array of results, you pick the least sketchy-looking one.  You enter your text, save the QR code, and quickly close the browser tab.  Why so furtive?

Because you know that the site's not just randomly passionate about giving free QR codes to the world -- it's not some Johnny Appleseed of machine-vision -- someone expects to get paid.  And that's why the page includes ads, it's laden with trackers, whatever you type is sent to a remote server, and it's setting all kinds of cookies on your browser.  All for just a QR code.

"Isn't it possible to just make a one-page website that uses Javascript to generate QR codes?  Something I could save to disk and run locally," I pondered.

Yes.  Yes it is.  (Spoiler, here it is.)

In about 19k of HTML and Javascript (and half of that is comments and easter eggs) it does exactly what you'd expect.  You type something, it makes a QR code.  You can also set the size, error correction, and colors.  And that's it.  Just a QR code.  Holy heck it works.  And there is no "pro" plan.

I uploaded it to my webserver for sharing.  And as I looked at the URL I realized, yes, I definitely need to be paying for another single-project custom domain name.  My project shall have no path in its URL!  It shall be the one and true main page.  After half an hour of trying to be clever, I discovered that "just a qr code" dot com was available for ten bucks.  Sure, whatever.  Ship it!

I present to you: justaqrcode.com

Check it out -- you can view the page source and confirm that it doesn't send anything anywhere.  There are no trackers.  You can save it to your local disk and run it from there.  Go ahead and modify your copy to suit your own needs.

What's my payback for the domain name and hosting costs?  I don't know.  But I'm really annoyed at the state of the world right now and this is somehow my way of fighting back.  I'll keep paying for the domain name and hosting, and you keep being awesome.

Building a Poetry Camera

Inspired by the official Poetry Camera -- and challenged by my brother -- I decided to make a poetry camera of my own, using a Beepy keyboard/screen on a Raspberry Pi Zero 2 W with a Gen 3 Pi Camera.  No custom case, nor printer, but it works just fine printing its poems to the screen.  My friends love it!

If you've got a working Pi with a camera, here's my script.  The README file has all the details on what you need to add to your Raspberry Pi base OS and how to run the script.  Have fun!

Opening the Garage with a Wave of My Hand

So here's the story.  To get into my building's garage, I need to wave an rf-enabled key at a reader.  Problem is that I ride, so I have gloves on.  I have to stop just before the gate, take a glove off, fish the key out of my pocket, stuff it into my other glove, put the first glove back on, then ride up to the gate, scan, and ride in with it still in my glove, fully expecting it to fall out on the way.

I don't know how many commas I used enumerating that long sequence of events.  Clearly too many.  Something must be done.  Think of the children.

So, I know that people are getting teenty-tiny rfid chips crammed into their hands.  What if I could glue/sew one of those onto my gloves?  (Spoiler: I ended up going a different way.)  Then I could just ride up, wave my glove, and ride on in!

Step one was to try to duplicate the key at all.  So I popped over to eBay and looked for a duplicator.  The popular match (a blue thing from China) says it's for 125 KHz and a quick search on the interwebs indicated that my keyfob likely is one.  They all come with a few blanks included, even.  I found a US shipper and committed twelve dollars to the experiment.

It arrived, I tried it out (beep boop!) and the duplicate fob it made worked just fine on the garage.  (And the building front door and the elevator.)  I enlisted friends and made copies of their keys for them -- those also worked!

Alright, now to duplicate my key onto a teeny-tiny chip.  That did not go so well.  I mean, I completely got the wrong type of chip, had no idea what I needed, and utterly failed.  (Though now I know exactly which one I needed.)

There's something really magical about showing people how easy it is to clone these things.  Particularly because there's something really magical about how your apartment building wants to charge you a hundred bucks if you ask them for a spare copy.  These things cost fifty cents, dudes!  (There's a reason why land owners are the first against the wall when the revolution comes.)

Back to the project though.  During my research I discovered that you can actually get a ring with a chip in it!  Add to cart! Ship it!

And ... success!  Now when I ride, I put on my ring, and opening the garage is just a wave of my hand.  Total cost of the parts (that worked) is under fifty bucks.  And my friends love me because I can make them spares, too.  This was a good project!

Updating the Kernelcon 2022 Badge Wifi

So you got home, powered up your Kernelcon 2022 badge, and discovered that it won't boot without the conference wifi network?  It took me a little bit, but I finally figured out how to reflash the thing with new wifi settings.  Turns out you just need to teach an Arduino IDE to talk to an ESP 8266 board, and you can upload the code with new wifi settings easily.

Let's do the Arduino set-up first:

1. Download and install the Arduino IDE
2. Open it up and go to File > Preferences
3. In "Additional Boards Manager URLs" add
   https://arduino.esp8266.com/stable/package_esp8266com_index.json
4. Hit "OK"
5. Go to Tools > Board: ____ > Boards Manager
6. For "Filter your search" type "ESP8266" and let it find the module
   
7. Click "Install" and it should download and install the add-on
8. Click "Close" when that's done
9. Select Tools > Board: ____ > ESP8266 Boards > Generic ESP8266 Module
10. Select Tools > Flash size: ____ > 4MB (FS:1MB OTA:~1019KB)
11. Plug in your badge and switch it on
12. Go to Tools > Port and select the port it's on.  (Kali picked /dev/ttyUSB0)

At this point, you can load whatever Arduino code you like.  The official Kernelcon badge code uses a JSON library, so if you're going to reload the official code, install the JSON library first.

1. In the IDE select Tools > Manage Libraries
2. Search for "ArduinoJson" and click "Install" to add it
3. Click "Close" when it's done installing.
   

Finally, let's fetch the original badge code, update the wifi settings, and upload it to the badge.

1. Download and unzip the ZonkSec kernelcon-2022-badge code
2. In the Arduino IDE, open kernelcon_watch_v4.ino
3. This opens all the source files.  Select the wifi.h file tab
4. Update the SSID and password values and save the file
5. Select Sketch > Upload and watch it compile and transfer
6. The badge will restart, and it should use your updated wifi settings as it does.
   

That's it!  Mess around with the badge code some more, if you like.  Or go find some ESP8266 code and mess with the little guy.  For me, my next step is to try to get the original deauther code running.