Features: brand new and high quality STC15W204S Development Board Support all IO ports lead out With LED single-chip control, connected to IO port P3.2, which can be used for IO port output, PWM modulation and other experiments With patch switch, connected to IO port P3.3, can be used for IO port input, and other experiments The external chip switch and LED of the IO port will not affect the normal use of the IO port. With TTL level serial port, (connected to P3.0) and (connected to P3.1) can be used for STC download program/serial port host computer communication (with timer matching) and IO port input and output experiments Package Includes: 1 x STC15W104W MCU / 1 x STC15W204S MCU minimum system board development board Specifications: Size:approx 1.8x1.1cm/0.71x0.73in Type: STC15W204S / STC15F104W for STC15F104W Development Board Descriptions as below: Timer modules: for T 0 and T2. When for T 0 works in mode 0, it is a 16-bit timer counter, which can automatically re-load the initial value; In mode 2, it is an 8-bit timer counter, which can be automatically re-loaded; When mode 3, and decomposable. The working mode of T2 is fixed as 16-bit automatic re-loaded initial value mode, which is especially suitable for the LED industry. The chip's timer module can generate higher-precision timing. STC15F104W has no serial port and relay broadcast mode. It can simulate I2 C, serial port, SPI, measure external voltage through IO port, and realize AD function. note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment