Control circuit of handheld unit

The invention relates to the field of domestic direct drinking water dispensers, in particular to a control circuit of the handheld unit. The control circuit comprises a keyboard connecting terminal Key_P3, a liquid crystal display interface circuit, an infrared transmitting circuit, an infrared receiving circuit, a crystal oscillation circuit, an EEPROM (electrically erasable programmable read-only memory) circuit, a communication interface P6 terminal and a single-chip microcomputer STC10F08XE. The control circuit allows service status signals of filter elements of the direct drinking water dispenser to be fed back to users in time, the users are allowed to conveniently replace corresponding filter elements in time, and filtering quality is avoided being affected.