开源的硬件中文教程，主控室atmel（AVR单片机），外设可以直接连接串口，WIFI，蓝牙等模块，IOT方面使用比较多。(Open source hardware Chinese tutorial, the main control room ATMEL (AVR microcontroller), peripherals can be directly connected to the serial port, WIFI, Bluetooth and other modules, IOT use more.)