Single-chip microcomputer communication circuit without serial port function

The utility model discloses a single-chip microcomputer communication circuit without a serial port function, comprising a single-chip microcomputer U1, a single-chip microcomputer U2, a pull-up resistor R1 and a pull-up resistor R2, the single-chip microcomputer U1 and the single-chip microcomputer U2 respectively comprise a data transmitting end and a data receiving end, one end of the pull-up resistor R1 is electrically connected with the data transmitting end of the single-chip microcomputer U1 and the data receiving end of the single-chip microcomputer U2, the other end of the pull-up resistor R1 is electrically connected with an external power supply and one end of the pull-up resistor R2 respectively, and the other end of the pull-up resistor R2 is electrically connected with the data receiving end of the single chip microcomputer U1 and the data transmitting end of the single chip microcomputer U2 respectively; and data intercommunication between the two single-chip microcomputers is realized by chang