Pic16F688 Based-Voltmeter
Chapter Three
System Design and Methodology
3.1 Design Outline of the System
The process of circuit design begins with the specification, which states the functionality that the finished design must provide, but does not indicate how it is to be achieved. The initial specification for this project is a dc voltmeter with an input voltage range of 0 to 300 volts. Although there are many parameters that a design specification should contain, such as size, weight, moisture resistance, temperature range, thermal output, vibration tolerance and acceleration tolerance but we shall only pursue electronic circuit specification here. Next is the design process which involves moving from the specification at the start, to a plan that contains all the information needed in order to physically implement the design. This normally happens by passing through a number of stages, although in a simple circuit like it may be done in a single step. The process normally begins with the conversion of the specification into a block diagram of the various functions that the circuit must perform normally referred to as a "black box" design. This approach allows the possibly very complicated task to be broken into smaller tasks which may either be tackled in sequence or done at random and then fixed together to make a whole.
Each block is then considered in more detail with a lot more focus on the details of the electronics functions to be provided. At this stage it is common to require a large amount of research or mathematical calculation to achieve component specification. Then the individual circuit components are chosen to carry out each function in the overall design, at this stage the physical layout and electrical connections of each component are also decided.
At the end, system design process will yield a circuit diagram that properly implements the initial specification. Using the circuit diagram, the mode of operation of the circuit can be explained.
3.2 System
System Design and Methodology
3.1 Design Outline of the System
The process of circuit design begins with the specification, which states the functionality that the finished design must provide, but does not indicate how it is to be achieved. The initial specification for this project is a dc voltmeter with an input voltage range of 0 to 300 volts. Although there are many parameters that a design specification should contain, such as size, weight, moisture resistance, temperature range, thermal output, vibration tolerance and acceleration tolerance but we shall only pursue electronic circuit specification here. Next is the design process which involves moving from the specification at the start, to a plan that contains all the information needed in order to physically implement the design. This normally happens by passing through a number of stages, although in a simple circuit like it may be done in a single step. The process normally begins with the conversion of the specification into a block diagram of the various functions that the circuit must perform normally referred to as a "black box" design. This approach allows the possibly very complicated task to be broken into smaller tasks which may either be tackled in sequence or done at random and then fixed together to make a whole.
Each block is then considered in more detail with a lot more focus on the details of the electronics functions to be provided. At this stage it is common to require a large amount of research or mathematical calculation to achieve component specification. Then the individual circuit components are chosen to carry out each function in the overall design, at this stage the physical layout and electrical connections of each component are also decided.
At the end, system design process will yield a circuit diagram that properly implements the initial specification. Using the circuit diagram, the mode of operation of the circuit can be explained.
3.2 System