ARM mikrodenetleyici tabanli kablosuz veri kaydedicisi

The aim of this study is to design a battery powered, wireless data logger which has multichannel sensor support as well as real time data monitoring support using ARM based STR7 (from ST semiconductor company) microcontroller. Most data logger have limited, not expandable memory, require a connection to a computer for retrieving and monitoring the stored data and support only one or two sensors. The designed data logger overcomes all these limitations and shortcomings. It uses FAT (File Allocation Table) file system on the SD (Secure Digital) card rather than EEPROM (Electrically Erasable Programmable Read-Only Memory) hence no special software is required to read the stored data.Another important advantage of our data logger project is that it has a PIC16F877 (from Microchip company) microcontroller based battery powered handheld controller device which can control the data logger and get the wireless data transmitted from the data logger in real time. Most data loggers need a computer for real time data monitoring but this handheld device can monitor the data coming from the data logger.The data logger stores the data from the sensors continuously but doesn?t always transmit them in order to save power. The receiver, by sending special instructions to the logger, can start data transfer, can get current date and time, can modify the date and time, and also change the sampling frequency.