Các thông tin trong chương này sẽ giúp bạn thực hiện quyết định của riêng bạn về những vật liệu và kỹ thuật xây dựng bạn sẽ sử dụng sau khi xem xét chu đáo của nhiều loại của các yếu tố và các ốc vít có sẵn. Mỗi vật chất có một ứng dụng tốt nhất. Trước khi bạn bắt đầu xây dựng, bạn nên xem xét | 262 Build Your Own Combat Robot Table 12-1 shows a list of some specifications to several different types of microcontrollers. The number of input and output I O lines represent the total number of individual control lines a microcontroller can have. This list combines both digital and analog I O together. Digital I O represents a data line where the input and output values are either 5 volts or 0 volts. This is to represent a binary 1 or a 0 or in other words and on or an off state. An analog I O signal line represents a line that can interpret a variable anywhere between 0 and 5 volts. A microcontroller s processor speed is the actual clock speed. Some microcontrollers require the four clock cycles to execute a single command while other microcontrollers can execute a command in a single clock cycle. The time required to execute a command doesn t represent the time required to execute a line of programming code. When you write a program each line will use many different internal commands that the microcontroller understands thus program speeds are always slower than clock speeds of a microcontroller. The specification that is really important is the execution time which is the number of program instructions executed per second. Notice in Table 12-1 the difference in execution times when compared to the clock speeds of the microcontroller. For programming space the common term that is used to represent how much memory a microcontroller has is electrically erasable programmable read only memory EEPROM which is the number of - kilobytes of programming memory available on the microcontroller. In the microcontroller world memory represents how much variable space the program can keep track of not the amount of Feature Basic Stamp 2 Basic Stamp 2SX Basic Stamp 2P Basic Stamp 1 BasicX-24 OOPic BrainStem Handy Board Bot Board I O Lines 18 18 12 8 16 31 25 30 38 Processor speed MHz 20 50 20 4 8 20 40 2 8 Execution time 4000 10000 12000 2000 65000 2000 9000 N A N A EEPRPOM
