A data logger is any device that can be used to store data. This includes many data acquisition devices such as plug-in boards or serial communication systems which use a computer as a real time data recording system. The Microcontroller Atmega 32 has 32K Bytes of In-System Programmable (ISP) Flash Memory.
now when compleat this circuit then burn the hex file througt USBtiny programmer or any other AVR programmer (USBasp or serial AVR programmer ) then put the memory card in the slot and appy the power supply then tempetarure data store with RTC clock data.
yoy can access this data with MS word and MS exel.