SDIO: data port GPIO: It may also be a data port or a interrupt (no chip or circuit diagram, can not be judged) GND, 3V need not explain. Directly use IO port control, it is estimated to simulate SPI timing.
Note that the IO port of nRF24L01 should be connected to the "high resistance pin" of the 51 MCU (generally P0 port). However, some models of P0 are not high resistance, please check the chip's manual for this.
NRF905 wireless communication module is SPI interface communication, if I remember correctly, it should be 3V power supply; singleThe general I/O port of the chip can be connected, the general I/O port can use software to simulate SPI communication, if you use the single chip microcomputer with hardware SPI module, it is recommended to use the special SPI interface, because the speed of using the general I/O analog SPI is not faster than the speed of the special SPI.
Method 1: Using a MAX232 chip on the MCU board to connect the serial port on the board with the rxd and txd on the MCU, and then using a usb to serial cable to connect the pc and the serial port on the MCU board. Method 2: Find one end is usb port, the other end is vcc,