This project intends to create a working Linux device driver for the Dream Cheeky USB Webmail Notifier.
The device itself consists of a small plastic shell in the shape of an envelope. According to the website, its physical dimensions are approximately 4.7cm x 7.5cm x 3 cm. The picture below demonstrates its appearance when lit:
On a more technical note, the USB vendor and product ID are as follows:
Vender: 1d34
Product: 0004
This device employs an extremely simple protocol. Using a USB logging tool, I discovered that the device consists of three LEDs - one red, one green, and one blue. They can each be set to one of 0x40 different intensities.
A sample block of data sent to the device to make it appear blue would look like this:
00 00 40 00 00 00 1f 05
I have no idea what the 1f 05 is for, but it seems to exist in every command dispatched, so I include it when sending commands to the device. Perhaps some more experimentation will reveal its purpose.
Building the module is easy if you have the headers for your current kernel installed. Just run:
make
You can load the module into the kernel with:
insmod webmail_notifier.ko
Assuming you either have the device plugged in or plug it in after loading the module, you should have a file /dev/wn0 that you can use to control the device. Color values are specified using CSS hex notation:
echo "#ff0000" >/dev/wn0
Using the above command will set the device color to red.