Design Of Wireless Temperature Detection System For Casting In Thermostatic Furnace

In order to meet the requirements of real-time temperature detection of castings in constant temperature furnace without measurement errors caused by human experience, improving the production efficiency, reducing energy consumption, this detection system was designed, which realized real-time temperature detection of castings in multiple thermostatic furnace with wireless methods.In response to the demand for temperature measurement of castings,temperature wireless detection system was developed using intelligent temperature sensor DS18B20 and wireless transceiver chip nRF24L01.STC89C52RC chip was chosen as system processor,which contained data acquisition,wireless transceiver,data display and casting mobile control circuit.Using 1-wire bus technology,12Byte digital signal sent by sensor was converted to temperature data by data acquisition terminal, which transmitted those data to nRF24L01 data registers through simulation SPI interface and it would also push the casting out automatically if its temperature went to the perset point.Wireless transceiver chip adopted SchockBurstTM technology, thus CRC code could be generated automatically and temperature data in registers would be sent together by it. After local address and CRC code detected was correct, data could be downloaded by receiving client, which achieved those functions,such as real-time temperature display, automatic alarm and manual control.Real-time display circuit was built using LCD 1602 as its core,which realized real-time display for both temperature of castings in different thermostatic furnace and alarm graphic.Driving circuit was built with ULN2003. When the temperature reached the preset point, dirving circuit could push casting out of constant furnace automatically and this function could be lanched by manual control at any process.Using insulation properties of siliceous aluminous fiber cotton,an heat shield was constructed,which could ensure the system in the oven to safe, effective and stable operation.With this designed system, a number of tests had been done in 200℃thermostatic drying oven.Its temperature detection precision was less than 1℃, and system could satisfy the requirements of real-time detection of castings in multiple constant temperature furnace.