This project essentially consists of a microcontroller affixed inside the base of a counter bell, that pulls on the bell's clapper with an electromagnet, and communicates with the computer over USB. WAIT! COME BACK! Don't run away, I haven't told you how easy this project is yet!
This project is reasonably easy,
Here's a video of the bell in action, I am sending myself some emails, and as they appear in Thunderbird, the bell goes ding.
Some skills required:
1. soldering - you'll need to solder just six electrical components together
2. electronics knowledge
3. knowledge of programming is entirely optional if you use the same microcontroller as I do since I've made all the code and firmware online so you can quickly download it and load onto the microcontroller over USB
Materials required (details to follow):
1. A counter bell of some sort with a steel clapper
2. A short bolt (to make a solenoid/electromagnet)
3. Some thin (less than 26 AWG) enamelled wire (about 2m)
3. A transistor
4. A resistor
5. A large capacitor (because USB probably won't supply enough power in one go to fire the electromagnet
6. A diode (flyback diode, as safety to avoid things blowing up)
7. A Forebrain (LPC1343 microcontroller) dev board (or you can use an alternative microcontroller/dev board if you want to have a go at coding it yourself)
8. Some prototyping board and wires
You will also need a soldering iron, some type of tape or adhesive to attach things to other things, and possibly some kind of cutting tool to cut a slot out of the base of the bell for the USB plug. And of course a computer (sorry, I only supply source and binaries for WIndows, the bell appears on a computer as a generic USB HID device, for which all modern operating systems have drivers built in for, so it would be relatively easy to code it for Linux or Mac).
Note: the bell does not check your email for you; you will need some sort of program on your computer to check your email and then activate the bell when you receive new mail. For Windows, the Thunderbird mail client works perfectly for this, or alternatively a utility called POP Peeper (more on this later).
Here is another video where I am triggering the bell manually from the computer. The bell plunger occasionally gets stuck, but I've since fixed that with some WD40.
WARNING: This project involves powering a home-made solenoid via the USB port, which may risk damage to your computer if your solenoid draws too much current. I highly recommend using a cheap powered USB hub. I accept no responsibility for any injury to you or damage to your equipment or property should you choose to attempt this. Please proceed AT YOUR OWN RISK.
Step 1: Parts: The Bell
Pushing down on the top arm of the clapper would send the bottom half kicking out and striking the stainless steel bell. I figured I could place an electromagnet underneath top arm of the clapper and attract that downwards to ding the bell.
If your bell is different from this, you'll need to figure out a way to mount your electromagnet, and if the clapper isn't steel or iron, you may be able to get around it by affixing a magnet to the clapper and attracting/repelling that instead.