The processor used in keyestudio EASY plug control board V2.0 is ATmega328.
It has 5 single Digital ports labeled D5 to D9 (of which 3 can be used as PWM outputs), 1 dual-digital interface (D3-D4), 4 analog inputs (A0-A3), a Joystick interface (D2-A6-A7), a SPI communication, a serial port communication and an IIC communication interface. Also with a USB connection, a power jack, two ICSP headers and a reset button. It breaks out the IO ports with RJ11 6P6C plug.
Simply connect it to a computer with a USB cable or power it via a DC jack to get started. For convenience of wire connection, we simplify the pins GND and VCC into each plug, so you only need one RJ11 6P6C connector wire to connect an external sensor or module, no need to separately connect the VCC and GND. So don't worry that the wrong wiring will damage the external products.