Interfacing PIC Microcontrollers 8. Explore in detail microcontroller interfacing techniques using the popular PIC 16F877 Work through step-by-step examples interactively using circuit simulation software, supplied as assembly source code Gain the knowledge of a wide range of peripheral devices such as keyboards, displays, sensors and drives and serial communication with other processors, memory and more Use interactive simulation software to design and test circuits. | Interfacing PIC Microcontrollers resistors in series this becomes V I R1 R2 . The power dissipated in the resistor is given by P IV. For AC signals RMS voltages are used so that the same model can be applied. Reactive components need the frequency of the signal to be included so V IX is used where X is the reactance. For a capacitor the magnitude of the reactance is 1 mC for an inductor rnL where C is the capacitance and L the inductance. We then need to model the phase relationship between voltage and current using complex numbers and so on. Digital circuits are in principle easier since they are modelled using simple logical relationships such as A where the dot represents the and operation. The other main operators are representing logical or and logical invert. Thus a simple logic function may appear as A D . The next step is to model mixed mode circuits with analogue and digital components connected together. Then microprocessors needed to be added which needed a programmed model to represent program execution. Computer graphics have now developed to the point that the modelling can be done in conjunction with a circuit drawn on the computer screen and a simulation generated interactively. Components placed in the drawing have their models attached and the nodes are identified from the connections on the schematic. Inputs can be supplied from simulated signal sources and virtual instruments and on-screen graphics are used to display the outputs obtained. Interactive circuit simulation now makes the job of analysing and designing electronic circuits quicker easier therefore cheaper and more fun The circuit can be drawn and tested on screen and a PCB layout also generated from the schematic. Simple one or two sided PCBs can now be produced directly by a machine tool attached to the same computer avoiding the usual chemical process. Once in production assembly and testing can also be automated. Proteus VSM Virtual System Modelling from Labcenter .
