Convert a wired USB keyboard to a wireless / Bluetooth keyboard

This is more of a hack (or a mod maybe?), but it's an easy workaround when you really-really-really need to use your wired keyboard as wireless. Sample situations include:

• Your device has limited USB ports, and all USB ports are taken.
• All the USB ports are at the back or some inconvenient location, and your device is too heavy to turn around.
• The cable of your wired keyboard is too short, which anchors you to just one side of your desk.
• You do not have the budget or the time to buy a wireless keyboard.
• Your IT department keeps ignoring your request for better hardware.

Before you begin, make sure you have the following hardware ready:

•   Your wired keyboard
•   An Android smartphone
•   An OTG adapter
•   The target PC / laptop / device

I believe you can see where I'm going with this. Basically we're creating a portable dock for the keyboard, using the smartphone to transmit keystrokes to the PC. The target PC can have be any OS, but I'll be referring to it hereafter as the "Windows PC" since that's what I'm using. 

1. The first step is to find an Android app that can connect your mobile device as a remote keyboard/ mouse to the Windows PC. There are hundred of these apps, but choose one that is compatible with your Android version and Windows OS. Most will require the installation of a server component to work with your network, but there are a few that will only require a solid Bluetooth connection.
2. Second, test the app if it can connect successfully. Make sure that the app works flawlessly. There should be no issues pairing the phone with the PC.
3. Use the OTG adaptor to connect the wired keyboard to the phone's USB port. Afterwards, go to the app's keyboard feature. Using the wired keyboard, type a few words to test if the app can recognize the input.
4. On the Windows PC, open notepad or some other program that can accept text input. Again, type a few words on the wired keyboard to test if the text was successfully sent to the selected program.

I really can't recommend this for daily use as this method is prone to a lot of issues:

• Depending on your connection, there might be a delay in tapping a key and seeing it on screen. Good for coding or just writing, but really bad for gaming.
• Obviously you need to reconnect again at every reboot. You would still need a primary keyboard to handle keystrokes at boot time. 
• Phone can go hot and start throttling the connection. You also need to make sure that the phone stays on. If it sleeps, your connection could be lost.
• Since Windows only allows one mouse to be active, some apps disable the 'hardware' mouse during connection so only the 'virtual mouse' is usable. Sometimes you can force-enable the hardware mouse by re-plugging it again.
• The keyboard is now tethered to the phone. All the time. Maybe you can assemble a dock or something similar that keeps the phone and keyboard together.

With that said, it's still a good trick for emergencies. I do enjoy having the ability to freely move my keyboard across my desk. Even better if you're connected via wireless LAN; keyboard works as long as it within range. If I'm ask to present and cast my screen to the big TV at the back, I can now bring my keyboard with me.