Development of embedded system for monitoring temperature of blood bank

The human blood is analyzed for three main components as plasma, platelets and red blood cell. Those components of blood must be safekeeping inside refrigerators. There are many refrigerators inside blood bank center. In this thesis, we have developed a embedded hardware and software for monitoring of temperature of 24 refrigerators inside blood bank center. Embedded hardware is implemented with microcontroller, oscillator circuit, CAN integrated circuit for CAN bus, and LCD. Due to the security of locations in the blood bank hall and difficulty of monitoring of each refrigerator separately, this work proposes a solution to monitor temperatures of all the blood bank refrigerators in one location. CAN-bus system has been used because it has many advantages. Especially it has been preferred due to easy in use, low cost, providing a reduction in wiring, fast to repair and easily expanding. PIC18F458 microcontroller has been used in embedded hardware design to execute embedded software. As a temperature sensor, LM35 integrated circuit was utilized. Embedded software's have been developed by using C language on MPLAB IDE. The designed system has ability of detecting temperature in the range between –55°C and +150°C. The temperature sensed by sensor is compared with the setting value by the user and if the temperature goes beyond the preset temperature, then buzzer and a red LED will be active. Also, the address of each refrigerator is sent to LCD display so operator knows which refrigerator fails.