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Rain Gauge Data Logger Using AVR
A tipping-bucket rain gauge contains values that are being saved by this data logger project in order to determine and measure the intensity of rainfall.
The values are being stored by the onboard 512kB data flash and through the RS232 serial port is where the readout to the Windows download software developed for this project takes place. The coin cell on is not a reliable energy source since the data flash needs up to 45mA during writ to flash operations. The coin cell serves as a backup battery in the logger while the three AA alkaline batteries are the main supply. The GCC-PORT of Atmel application code is used as the firmware code and the maximum external voltage is 4.5V from the manual.
The firmware contains a real time clock and date and the data flash is a low level access where its management functions as a ring buffer. For external batteries, a fail detection is created and modifications on power save was implemented. The debouncing of the rain gauge reed contact is present and a display is used for logger status. The transfer of logged data is through RS232 to Windows.