![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwpBV949_DYufYdXzboLPzIMDNJP48q3kzLu-EGxyHfrwrbj6zp8RqlbUVqHPoTQD4-ypxLcXf6sBXdoCUco9hbcyM-0f9XVfJIryLdc0psQjfukN-hgN_akEbmx44va0lDKIjO7pkr-o/s200/teasef4+014.jpg)
They are always around work... discarded in various sideways... and it gets us thinking - what can we do with them?
How about annoy friends, family, and strangers!
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhfOGDGm5V8CLkspRJxUcGll0ePmxda4RL6ko9XiOta8P84rYIYT72g8z15sMWWAX_jdp6JKgyhqkcqzHUTmBQa6YwwhkGkT870_sRHx5uTsOHVwVWUUjrPwJWD_pR6P3ITFnvfc9vL0p4/s200/teasef4+042.jpg)
This controller can easily be embedded inside the keyboard to run off the keyboard's power and do our will.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiF7KaC-dqqrfd1W-IYADbuAFr2m5sZ2yXqgdN8TZqHR0ikcZZjkfVetEOHAk0LZnub1xxHyZiPKcyYGu5JL3Ik7TRwsLur9kuU8Kg6ypyVev3az4OTS2b3MfsMyCdGUZfyMyCUR4d7QYA/s200/teasef4+043.jpg)
This is the danger of our society - cheap (or even free) technology that is not only powerful but even dangerous - all in the hands of bored teenagers and persons of questionable intent.
Instead of having this controller record all keystrokes that it then emails to us automatically, we will instead make a prank keyboard. The microcontroller will wait patiently inside the keyboard for a random amount of time, and then, out of the blue, type its own random (and extremely annoying) message to the user!
No one ever suspects the hardware - they always assume they have a virus or other threat.
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After the software is working, we will simply glue our controller to an empty space on the circuitboard, and wire our pins to connect to the cable pins
The software is simple - we select a random number between 1 and 65535, and tell the chip to sleep for that many seconds. When the chip wakes up, it will simply use the data and clock signals to talk "keyboard talk" to the users computer and send our own silly message. The great thing about the old PS/2 keyboard protocals is that they are simple, and when our chip takes control, the keyboard itself will wait patiently until we are done. The PC thinks it is the keyboard and will receive all of it just as patiently.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjw9dxC5Uz8NH2Z_gflGlr7k6rv-8Z9xjBUF8HlB0XJ6paMNKEpGOr-3B725HgwoFnYnw9E8LVp4_8lwpr-OxvnitrEDUaOr6wlaAlcJ6E_vMKbn1iGrzbG4wZjvQrbxfiumsGKEKydD2I/s200/teasef4+047.jpg)
We are barely using any code resources on the chip. For $2 we can utilize more computing power than NASA used to land a man on the moon - and it runs off a single AA battery if we wanted it to!
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Now, we simply put our 'modified' keyboard back in the pile, and wait for a surplus scrapper to give the keyboard to some public school or 3rd world country to use.
Of course, we are only doing this for an academic exercise and would never inflict this on an innocent... we are just making the point that we should all be careful out there - especially with 'free' hardware!
Kind of fun thinking of other mischief to do... isn't it!