The design which controls the humidity and temperature of the greenhouse is based on the single chip computer. Its body is made up of the temperature sensor DS1820, the single chip computer A89C51, the data-carrier storage 6264, the connection chip 8255, the humidity sensor, the alarm circuit and latch 74LS373. This system has some advantages, such as the high running speed, the convenient installment of the sensor, the high precision, the good stability and so on. And its main technology is the 1-wire transmission. This system is not only suitable for the temperature control of vegetables greenhouse, but also for the technology of some higher requests to the temperature, and it may widely apply to these industrial productions, and it has good popularization. This system carries on the multi-spots temperature tour test control to the vegetables greenhouse, and can automatically judge the temperature whether it exceeds the allowed figure, and may start up the intelligent control equipment, and it has a good reliability. The system is composed of the hardware and software. The design of the hardware circuit includes: the choice of single chip computer, the design of the I/O and A/D, the test of the humidity and temperature and the design of the alarm circuit. The software part includes: the main procedure, the subroutine of the correspondence agreement of the 1-wire, the DS1820 read-write subroutine, the subroutine of the demonstration renovates, the subroutine of the alarm processing and so on. Keyword: 1-wire; single chip computer; temperature and humidity control; DS1820; Data-carrier storage; Latch
