The Timer Circuit Essay

Step 2 The Timer Circuit

The circuit that I built uses a 555 timer IC to send a series of pulses to the left mouse button to activate and deactivate the clicking function. The frequency is determined by the values of the resistor and capacitor. With the values that I used, the rate was about 15 clicks per sec. Power for this circuit is supplied by the 5 volt line from the computer that also powers the mouse. The output of this circuit is a series of pulses that are equivalent to 5 (High) and 0 (Low) volts. To prevent circuit form the shorting out, a small diode is added to the output in case is the rapid fire button and the left mouse button where ever pressed at the same time. A small momentary switch serves as a rapid fire button, which is added on the left side of the mouse.

Step 3 Prototype and Test the Timer Circuit on a Breadboard

First start prototyping the circuit on a breadboard, to test it you can connect it to the mouse with alligator clips. You need to connect pin 4 and 8 on the timer to one of the 5 vault pins on the mouse. Then connect pin 1 on the timer to one of the ground pin on the mouse, lastly connect the Diode from pin 3 to the momentary switch and connect that to the terminal on the left mouse button that is not connected to 5 vaults. Once you have done everything as it is shown on the infographic, then you are ready to connect and test whether your circuit is working or not.

Step 4 Identify the Positive and Negative Terminals on the Mouse

Before you can connect the 555 Timer IC circuit to the mouse, you need to identify the positive and negative terminals on the mouse. The easiest way to locate the terminals is to follow the connections from the USB connector. You can also use the multimeter to check which terminals are connected to each other. If do not have such instruments there is an illustrated infogrpahic, which highlights each step, so you can easily identify the negative and positive terminals on the mouse. 

Step 5 Connect the Breadboard Circuit to the Mouse

If you have already identified the positive and negative terminals it is time to wire the breadboard circuit to the mouse by connecting the corresponding terminals of each one together (For example Connecting negative terminals of the mouse to negative terminals on the circuit). You also have to connect the output wire of the circuit to the terminal of the left mouse button that is not connected to positive. For now, everything is connected using alligator clips, in order to avoid any mistakes until we start soldering.

Once everything is connected, you can test it by plugging the mouse into a computer and pressing the rapid fire button. If it is working properly then the computer should register