Mutchus

This is the simple Logic probe yields three discrete states circuit diagram .The circuit uses a dual LED. When power is applied to the probe throughthe power leads, and the input is touched to a low level or ground, Ql is cut off. This will cause Q2 to conduct since the base is positive with respect to the emitter. With Ql cut off and Q2 conducting, the green diode of the dual LED will be forward biased, yielding a green output.   Logic Probe Yields Circuit Diagram   Touching the probe tip to a high level will cause Ql and Q2 to complement, and the red diode will be forward biased, yielding a red output from the LED An alternating signal will cause alternating conduction of the red and green diodes and will yield an indication approximately amber. In this manner, both static and dynamic signals can be traced with the logic probe.

Finally you have decided to write your own code for the 8051 microcontroller. It doesn't matter whether you have chosen Assembly or C Language for yourself but what matters now is that you need an environment specially designed for 8051. Basically you are looking out for IDE (Integrated Development Environment) that will help you build and compile programs. While there are many options out there, I prefer KEIL uVision in this regard. UPDATE: You can also click this link for an updated version of this post. READ MORE

A use case describes a systems behaviour from the user's point of view Use cases are often used to help defined the systems requirements Use cases make use stick figures that represents a system user or ther system In use cases, system users are referred to as actors An elliptical symbol is used to represent the actual use case