1, 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.
2, Method 1: single-chip microcomputer board with a MAX232 chip to connect the serial port on the board with the single-chip microcomputer rxd and txd, and then use the usb to serial port line to connect the pc and single-chip microcomputer board serial port. Method 2: Find a usb port at one end and a vcc, ground, rxd, txd conversion cable at the other endThe machine is directly connected with a single chip computer.
3. NRF905 wireless communication module is SPI interface communication, if I remember correctly, it should still be 3V power supply; The universal I/O port of the single chip microcomputer can be connected, the universal 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 dedicated SPI interface, because the speed of using the universal I/O analog SPI is not fast.
4, note that the IO port of nRF24L01 should be connected to the "high resistance pin" of the 51 MCU (generally P