LCD

stm32输出四路pwm，能完成占空比可调，频率可变化的pwm(Stm32 four road PWM output, can finish the duty ratio is adjustable, can change the PWM frequency)

the function of the code is like a calculator.Basic calculator may be build by the code.

该项目首先是利用单片机对鱼缸的温度进行智能控制。首先通过外部按键对鱼缸所需温度进行设定。温度传感器 DS18B20 采集温度信息在外围的 LCD 上显示出来。其次是利用光电耦合器判断有无鱼饵，若无鱼饵，发出提示，若有鱼饵，则执行自动投食或手动投食功能。(The project first is the use of single-chip microcomputer to control the temperature of the fish tank. First, the temperature of the fish tank is set by the external button. The temperature sensor DS18B20 collects the temperature information to display on the periphery LCD. Followed by using photoelectric coupler to determine whether the bait, if there is no bait, alert, if there is a bait, automatic throw in and throw food or manually cast and functional food.)

用于水文频率计算的目估适线法,程序基于φ值表查询计算(Mesh used to calculate estimates of hydrological frequency fitting method)

at89c51snd1单片机SCMM的mp3播放程序源码 (SCMM at89c51snd1 microcontroller mp3 player source code)

这是有关pwm的控制，可以控制它周期的长短来控制灯的亮度，还可以控制它自动调光。(This is the control of the pwm, the length of the cycle it can be controlled to control the brightness of the lights can also control the automatic dimming.)

此程序为毕业设计之防火防盗报警器具有MQ2烟雾报警，DS18B20温度报警，红外传感器感应人体红外，超声波感应人得进入，加上1602液晶显示等功能，同时具有蜂鸣器及LED报警(This procedure for the graduation of the fire alarm system design has MQ2 smoke alarm, DS18B20 temperature alarm, human infrared sensor infrared sensor, ultrasonic sensor people allowed to enter, plus 1602 LCD function, but also has a buzzer and LED alarm)

说明：  尽管模拟高频头在开发中用得已经减少了，但是模拟电视接收功能在许多数码产品上仍有其身影。希望对本站的朋友有所帮组！(Although the analog tuner in the development of using has been reduced, but the analog TV reception capabilities in a number of digital products still has its shadow. Want to site a friend had to help group!)

利用51单片机做电阻测量仪，实现按键设置阻值自动报警提示(The use of 51 single-chip resistance measuring instrument to achieve automatic alarm button to set the resistance)

PWM调光 1、学习目的：利用定时器产生PWM，了解原理和使用方法 2、硬件要求：LED灯 定时器 3、试验现象：LED灯由亮到灭，由灭到亮逐步变化，也就是调光现象(PWM dimming, learning objectives: the use of the timer to generate PWM understand the principles and use hardware requirements: LED lamp timer test phenomenon: LED lights from bright to off, gradually changes from off to bright, that is, adjusted optical phenomena)