Survived the Polar Vortex!

Survived the Polar Vortex!

Life Below Zero

A few days ago, the North-East of the United States got nailed with temperatures to the likes of which have not been seen in a long time. During this cold time, I spent my time indoors working on some smaller projects. I also finally received my Barefaced bass cabinet, which I’m super pumped about.

The Barefaced Two 10S

My new bass cabinet, pictured with my ugly mug above, is a cabinet made by Barefaced, an England-based bass cabinet manufacturer, whose designs are incredibly light and powerful. That cabinet I’m leaning on weighs a mere 28 pounds! While it houses 2 x 10 inch drivers, a trained ear would probably say it sounds more like 2 x 12 inch drivers, or 4 x 10 inch drivers. It’s going to be my new gigging rig, and I’m in love already.

Smart-Homing Adventures

The old switch, with it’s confusing wiring.

This project was a runaway thought turned into and idea, and the rest is history. I discovered you can buy light switches for your house that can be controlled with either an external remote, or a phone application. I thought I would try my hand at it! I can tell you, wiring can be confusing until you sit down and really look at what’s in front of you, and use some analysis skills to figure it out. ALWAYS TURN OFF POWER AT THE BREAKER BEFORE WORKING ON YOUR OWN ELECTRIC. I’ll take no responsibility if someone turns themself into a Christmas tree. With a little work, and all of it being done while it’s dark, since the power is off, I got the new switch wired up, and it works great! Sadly, I didn’t get any pictures of videos yet, but I still may get some. Stay tuned for that one.

A Mechanical Ten Key

A Vortex Key Switch Tester, with PCBA and DSA keycaps.

As all of you should know, I love mechanical keyboards. My favorite keyboard right now is the Vortex Race 3, which you can read about in this post I made last year! Having a Race 3 at work also, I found myself missing my ten key, or number pad, but I loved the Race 3 and having that space back. Then I had an idea! What if I were to build a mechanical ten key, and place it on the opposite side of my mouse, so my desk would be laid out like:

[Vortex Race 3 75% Keyboard] [Mouse] [Mechanical Ten Key]

As it turns out, you can buy key tester kits, meant for testing various key switches, and add a PCB board to add the ten key functionality. I happened to find a drop happening on Massdrop for this Vortex 22 switch key tester, and ordered it, along with Cherry MX Brown switches, which are my favorite, and are equipped in both of my Race 3s.

The PCB board. The blue arrows point at what the keys do in those locations, in this case, =, Backspace, Tab, and Esc (function). The chip circled in orange is the micro-controller that makes the whole thing work, and the green circled components are diodes. I’ll touch on these later.

The PCB board can be seen above. When assembling a mechanical keyboard, there are a couple of primary parts: your case, your PCB, your back-plate, and your switches. Other pieces are stabilizers, and possibly the electronic components for the switches, such as diodes, resistors, and capacitors, if you decide to get a PCB with no components installed.

I circled the diodes in the picture above because they server an especially important purpose, and that is the prevention of ghosting. To simplify how a keyboard works, think of a piece of graph paper. When you pick any square, that square will only exist in one row, and one column. Now imagine your keyboard is the graph paper, and the keys are the squares. When you press a key, it will trigger one row, and one column on the keyboards micro-controller, telling it exactly which key was pressed. This is all fine and good until you start pushing multiple keys. When pushing multiple switches at once, your computer may no longer be able to tell which keys are pressed, and you experience a phenomenon called ghosting. Let me draw a picture:

When a key is pressed, it’s actually shorting out two lines right where you push, which provides a column and row sensor with information. In this case, sensors 2 and B detect a signal, therefore, S is being pressed
When two keys are pressed, and they don’t share any row or column, they will both be sensed, because there are no shared connections between the two.
Now, when we add the X key, when the S and C were already pushed, we actually make no changes to what the sensor is seeing, due to the sharing of the column and row with other pressed keys. This keystroke will not register, and suffers from what we call ghosting.

Now that you’ve had a crash course in ghosting, let me tell you how they create keyboards that don’t ghost any of your keystrokes. The ghosting occurs because the flow of current is actually able to flow both directions, and will pass back through pressed switches, which is the issue that causes ghosting. What a diode does, is basically make the key-switch a one way road. Current can pass through one direction, but cannot go the other. When you replace each switch with a switch-diode combo, you actually eliminate the ghosting issue. I did not have the time and effort in me to create another set of diagrams that included diodes, so please see these images I borrowed from PCB Heaven below:

As you can see, the current is able to pass through the right middle switch (pink circle), but cannot get back through to the other buttons in the row due to the diodes (purple) being present. The red line signifies the signal path. (Source: PCB Heaven)
Here, you can see the middle column keys getting pressed (pink), and producing an output that does not affect the third column, or the first column, since the diode is present to prevent current from flowing backwards into the pressed key, as can be seen on the right middle key. (Source: PCB Heaven)
Lastly, we have the first row. Since no keys are pressed, this row will not provide any signals to any of the rows. (Source: PCB Heaven)
All three of these are happening at the same time, and the machine is able to interpret every keystroke, achieving something called n-key rollover. With a keyboard that has n-key rollover, you could press every key at the same time, and the machine would register every keystroke, hypothetically. (Source: PCB Heaven)

Laptop Resurrection

Now that you’ve probably learned way more than you had planned on today, I’ll tell you very briefly about my last project, and leave you with something fun. I recently fixed a laptop for my sister-in-law, which gave me the opportunity to take a few pictures of the inside of a laptop. Here was my favorite:

What we have here is the Wi-Fi card. I’ve met people who think that Wi-Fi is just something that all electronics can do, but that’s not the case. A very specific set of hardware is needed. In laptops, this is often an mSATA expansion card. The two cables connected to it are the external antenna wires, which are hidden in the top of the case. This allows the WiFi to be able to pickup more signals from further away, therefore giving you better Wi-Fi reception. Truly fascinating how many parts go into making the computers we use every day.

If you stuck it out until the end, thank you for reading! I hope you learned something. As always, please leave a comment with your thoughts, and if you don’t have an account, make one! I’d love to have you a member of my site!

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