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Hardware Construction First, we will look briefly at some traditional techniques suitable for building one-off boards and prototypes, using the dice circuit in Figure 10.1. Then a slightly more elaborate general  purpose demonstration board will be designed and laid out in prototype form, and some programs provided to demonstrate its features and the related programming […]
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Logical Errors When all syntax errors have been eliminated the program will assemble successfully, and the hex file will be created. However, this does not necessarily mean that it will function correctly when downloaded to the chip; in fact, it probably won’t! Usually there will be logical errors, particularly when learning the programming method. Mistakes […]
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Software Design We can now start work on the software using a flowchart to outline the program. A few simple rules will be used to help devise a working assembly code program; these have been discussed in more detail in Chapter 2. A program consists of a sequence of instructions that are executed in the […]
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Interactive Debugging Interactive simulation of microcontroller circuits provides a powerful extra dimension in application design and debugging. Proteus VSM offers a complete design package, with schematic editing and capture, using a library of components which provides a graphical symbol for the schematic, a mathematical model for circuit analysis and component pin-out for use in the […]
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Software Design We can now start work on the software using a flowchart to outline the program. A few simple rules will be used to help devise a working assembly code program; these have been discussed in more detail in Chapter 2. A program consists of a sequence of instructions that are executed in the […]
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Hardware Design Before computer-based electronic computer-aided design (ECAD) was widely available, circuits would be designed as sketches on paper and a layout produced manually. In the absence of fast and powerful computer simulation methods such as SPICE, this process relied more heavily on the experience of the design engineer to be able to predict the […]
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Program Implementation When the program logic has been worked out using flowcharts, or otherwise, the source code can be entered using a text editor. Normally, the program editor is part of an integrated development package such as MPLAB. Most programming languages are now supplied as part of an integrated edit and debug package. Assembler source […]
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Hardware Testing Hardware construction will be covered in more detail in Chapter 10. For the moment, we will assume that suitable hardware has been constructed for MOT1 and we are ready to test it. When the program has been fully debugged in a simulator, it can be downloaded to the chip. In some cases, the […]
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VSM Debugging When the circuit is complete, and the MCU program attached, the simulation can be run. The logic levels on each connection are displayed as blue (low) and red (high). Clicking on the Run button in the schematic should make the motor appear to turn. The Up button should make it speed up and […]
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Test Schedule Using the simulator, the program function can be tested against the design requirements. The specification for MOT1 has been converted into a test procedure designed to exercise all its functions; we also need to anticipate incorrect input sequences that may cause a problem. It is difficult to anticipate exactly what kinds of logical […]
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