chips

Chip series number: MAX3224CPP 0817

14 digital input and output ports: the operating voltage is 5V, and each channel can output and receive a maximum current of 40mA. Each channel is configured with a 20-50K ohm internal pull-up resistor (not connected by default). Besides that, some pins have specific functions
Serial port signals RX (No. 0), TX (No. 1): Provide serial port receiving signals of TTL voltage level, and connect with corresponding pins of FT232Rl.
External interrupts (No. 2 and No. 3): Trigger interrupt pins, which can be set to trigger on rising edge, falling edge or simultaneously.
Pulse width modulation PWM (3, 5, 6, 9, 10, 11): Provide 6 channels of 8-bit PWM output.
SPI (10(SS), 11(MOSI), 12(MISO), 13(SCK)): SPI communication interface.
LED (No. 13): Arduino is specially used to test the reserved interface of LED. When the output is high, the LED is on, otherwise, the LED is off when the output is low.
6-channel analog input A0 to A5: each channel has a resolution of 10 bits (that is, the input has 1024 different values), the default input signal range is 0 to 5V, and the input upper limit can be adjusted by AREF. In addition, some pins have specific functions
TWI interface (SDA A4 and SCL A5): support communication interface (compatible with I2C bus).
AREF: Reference voltage for analog input signal.
Reset: Reset the microcontroller chip when the signal is low.
Communication Interface