simcom-sim5218

水箱水位自动控制系统,通过超声波对水位高度的检测，把数据传入到单片机中处理，得出当前水位，并根据当前水位的高低程度调控直流电机和步进电机转动实现水位的增加或减少，从而实现水位的自动控制。(the system of water auto control )

基于PIC16F877A的ht6221红外解码程序，测试通过(program based on pic16f877a，pass)

Certification Request Info for Andriod.

智能小车，89s52单片机，完成自动寻迹，占空比可调。分享一下。(Smart car, 89s52 microcontroller, complete automatic tracing, adjustable duty cycle. Share.)

APD，雪崩放大器。可以将光信号转变成电信号，用于光通信解调当中(APD, avalanche amplifier. Optical signals can be converted into electrical signals for optical communication demodulation.)

法国Humirel公司新一代HTU21D温度和湿度传感器驱动(The Humirel HTU21D is a new generation of temperature and humidity sensors)

说明：  这是基于STM32的80MHZ-110HZ频谱仪(This is a 80MHZ-110HZ spectrum analyzer based on STM32.)

pn532开发的单片机源代码，作为开发NFC的试验用,可读写ISO14443-A/B协议的射频卡和felica以及宝石卡(pn532 developed microcontroller source code, as the development of NFC test, can read and write ISO14443-A/B protocol and RF cards and jewel card felica)

说明：  基于串口通信输出pwm方波用于控制电机转动速度(Output PWM square wave based on serial communication for controlling motor rotation speed)

PT2314，音频通道4选1输出，有重低音、mute功能。(PT2314, audio channel 4 to 1 output, heavy bass, mute function.)