了解并掌握AD-DA转换芯片的基本原理 2.了解掌握I2C总线接口的工作原理及一般编程方法。通过改D[4]的值，实现模拟输出，学员观察学习板上DA处LED的亮度变化-Understand and master the AD-DA converter chips basic principles 2. Understand the working principle of the I2C bus interface and general programming. Through the chan

汇编语言，数/模转换器，模/数转换的基本使用，ADC0809的和DAC0832芯片的使用方法。-Assembler language use, the D/A converter, the basic use of analog/digital conversion, ADC0809 and DAC0832 chip.