1. Understand the parameters of ordinary light-emitting diodes and master the calculation method of current-limiting resistors.
1) The small LED light is lit by current, the voltage is 1.8v~2.2v, the current is 1~20ma, the brightness changes between 1~5ma, and the brightness remains unchanged above 5ma.
2) The algorithm of current limiting resistor is generally calculated using Ohm's law.
2. Understand the basic concepts of the minimum microcontroller system, microcontroller peripheral circuits, FLASH, RAM, and SFR.
1) The minimum system of a single-chip microcomputer consists of three parts, namely the power supply circuit, the crystal oscillator circuit and the reset circuit.
2) Flash is a program storage space that can be written repeatedly. It has large capacity and low cost. The data will not disappear after power failure. RAM is a data storage space. It is the same as computer memory. It has fast reading and writing speed and unlimited erasing and writing. , the data disappears after power off; sfr, is a special function register, which is used to read and write various functions of the microcontroller.
3. Understand the basic usage of Keil software and the microcontroller programming process, and be able to independently complete basic operations such as programming downloads.
1) Create a new project, create a c file for writing code, and complete the compilation.
Select the microcontroller model
2) Environment preparation ( download from http://www.keil.com official website)
Download: keil c51v954 and stc-isp read and write driver (required) Youdao dictionary, Fukuang reader (optional) Baidu network disk, please enter the extraction code 1 extraction code: 5151
3) keil5 writes programs, and stc-isp writes programs.