This is my version of ExtremeIce's (Eimod.com) auto-fire mouse circuit. Sadly, Eimod.com is not up anymore, so you can try this link to an archived page of Rob's article:

Extreme Ice auto-fire mouse circuit

Just in case the link to the archive doesn't work, you can check out the eimod.com entry from the Wayback Machine. Or, you can just refer to this schem, copyright to www.eimod.com:

Here's background. The Auto-fire mouse circuit gives you fast clicking capabilities for your mouse. Think of it as a "turbo" button on our favorite console controllers. Why do we need a turbo button on our mouse? The actual purpose for this circuit, as mentioned in the article, is to have a little "advantage" in counterstrike, mainly, for quick handgun shooting. It's is just a simple 555 timer IC based circuit. What it does is it sends the 1 and 0 signals to the mouse circuit telling it to execute the "click" command at a rate dependent on the resistors in the circuit. As for how exactly this is done, you can refer to the article for explanations in an electronics point of view :).

Now in my version, I have customized a few things. First, the resistors. The resistors determine the frequency to which the circuit will work. The equation (from Rob's article) is 1.44/(Ra+2Rb)C. Since 1.44 and the value of C is constant, you can change the values of Ra and Rb to set your timer frequency. Instead of using a static value resistor, I replaced them with two 1K Ohm variable resistors so I can fine tune them to my desired speed. I just used the smallest 1K Ohm variable resistors I can find in Radioshack. In this case, size matters, since you will be stuffing the whole circuit in your mouse. I forgot the actual value on my resistors but the frequency is at 5Hz. You can experiment on the Hz value to your liking by testing it on your favorite CS handgun. Setting it too fast can result to slow pistol shooting since not all pistols can be fired fast. Like for example, you can have it fire a deagle fast, but not as much on a p228. You can determine by sound and sight the fastest rate you can fire a certain pistol. If you can fire a deagle fast, and a p228 fast, you can see if your circuit is working like you expected. So far, I ended up with 5Hz since it can shoot the deagle, the USP, and the p228 at their maximum firing rate. Now, to test if your frequency is great, take out the dual berettas and see what you can do with it. with 5Hz, my dual berettas sound like a p90. Not exactly "sound" since it will depend on the WAV files of your guns, but it sounds like the fast fire rate if the p90. Pretty neat eh? At least you're not using a sissy script like some kiddies out there.

Next is the button to execute the auto-fire. I wanted to have it as small as possible so I tried using some small momentary tactile switches. They are small but stiff enough to press so I won't click on it accidentally. It does the clickity click sound like a normal mouse button so it kinda blends in with the feel of using a mouse. All you have to do here is to insert that switch in between the circuit and the mouse circuit. As for where to tap the output wire, most mice have three-pinned mouse buttons. Just activate the circuit and tap the output wire on each lead on the mouse button to see where it works. I just opened up CS and tested what lead would fire the gun. once you found it, solder the output wire there.

Another is an indicator LED. Wiring a LED on the circuit would also help you see how fast the circuit is running. The LED is wired on the output wire and the ground lead of the circuit. Here I found an issue with wiring the LED and the switch. At first, I wanted the have the LED light up (or flash in this case) when I pressed the auto-fire button. So I wired the + leg of the LED between the switch and the mouse circuit. Apparently, this made the mouse do a click-and-hold command. I asked Rob about this and he said that doing this sends an active low signal to the mouse button. I tried various ways to wire the LED to do what I wanted but I had no luck. So I just wired the LED between the switch and the auto-fire circuit, makit it flash at all times. Anyway, it made my mouse look nice with a little flashing blue LED :).

Ok, enough talk and now some pics.

This is how my circuit looks like and how I got it to fit my mouse. If you are familiar with that type of logitech mouse, there is a piece of heavy metal screwed at that location, giving the mouse some weight since it doesn't have a heavy mouse ball. I just took it off to make the circuit snug up the mouse dome. Plus it helped lighten the mouse up for full control, or not, whatever.

Here's where and how I installed the button on my mouse. The button had 4 legs, so I just punched 4 holes on the side of the mouse so it would be flat on the side. I dabbed a bit of superglue to help keep it on. Two small widths of heatshrink on the side made a little bevel :). Of course, the position of the button matters the most. Just find the spot on your mouse where you can reach it with your thumb, in the least amount of movement as possible for easy access. I was to put it somewhere above my thumb but since the button isn't that easy to press, I installed it on the spot where my thumb is, so my thumb is always on the button, kinda like how your index and middle fingers are on the left and right mouse buttons.

The legs of the button wasn't long enough to go through the side walls of the mouse. So I soldered some left over resistor legs to extend the legs of the button. So if you trim your resistors, keep the cut offs since they can be used as circuit jumpers and the like.