Pardon my ignorance on electronics, but why is that circuit necessary? The keyboard needs pullups to 5V on it's data and clock lines to function, per the PS/2 specification. The two resistors provide this. The LED limits the pullup voltage on the data line to about 3v so the Pi isn't damaged. Why n...

Similar, but this one uses AP mode, not an external access point. It also has rudimentary security for use in a multiple pad setup. Should also be cheaper to make.

Drive an analog microammeter using an underused function: the gpio oscillator. Simple circuit and kernel module makes this possible. This is actually a character type kernel module writing tutorial disguised as a project. https://sites.google.com/site/thepirow/home/pi2meter

Launch model rockets using your smartphone or other Wifi device (like in the the Apple ad). Code is set up for multiple pads in a school/club setting. Simple and inexpensive to build. https://sites.google.com/site/thepirow/home/pipad

Regarding using a mouse with this interface: on powerup, the mouse has reporting turned off. You have to send a command to turn it on. (at least this is what I understand reading the interface spec.) You can do this by bit-banging, but you will have to connect the clock line to the Pi and limit it's...

I should mention, the keyboard mapping will probably only work on a US keyboard. If you are using a different keyboard, the map table in the module will need to be edited. If someone is interested in these changes I wouldn't mind working with them.

Thanks for the diagram. I didn't have time to do one.

Yes, the LED acts as a Zener. LEDs are more easily available, and cheaper than the real thing. In fact, you probably have some laying around. The visual indication is an added bonus!

In my opinion, the Raspberry Pi's I2S peripheral is under-utilized. So to show what it can do, here is a little project I whipped up. It uses the I2S peripheral (with help from the PWM peripheral) to directly drive the CRT of a Mac Classic II. Details here: https://sites.google.com/site/7w0n0d3/home...

I worked out a way to inexpensively connect a PS/2 keyboard to the Pi's serial port. Project details here:

https://sites.google.com/site/7w0n0d3/home/pi2ps2

I have detailed instructions on module compilation here:

https://sites.google.com/site/7w0n0d3/home/modules

Hope this helps.

I have written up a step-by-step guide for compiling modules on the Pi running Raspbian. This is actually done on the Pi, not on another system. I also have tarballs of the Linux source that are ready for module compilation on my site. Eliminates about 1 hour of watching git do it's thing. https://s...