Here, the hyper-terminal connection is required only for setting RTC date and time. The project contains RTC interface (for date and time storage), RS232 (for connection with PC) and a microSD module. Here is the schematic (click on the images for larger view or download PDF): If you have directly landed on this page, it would be more helpful if you visit the original post first as it would be a better starting place for learning SD or FAT32 functions (also Check out my this post for updated version of this project with 16x2 LCD and DS1621 temperature sensor
But many users have requested to make the file creation independent of the terminal, done inside the microcontroller, so I'm showing here how to use those functions independent of terminal. In that post, the files were created using hyper-terminal and entering data with the PC keyboard, since that demonstrates the file creation and it's easy to debug. This project is an example of how to use the microSD FAT32 library presented in my earlier post.
A snapshot of the excel file is given later in this post. The data is stored in CSV (comma separated values) format, which can be read using a PC/Laptop with Microsoft Excel or other compatible software.
This project can be used to interface 8 different sensors with ADC of ATmega32, similar to the LM35 used here. One channel is used for reading temperature from LM35 sensor and remaining channels are used for simply reading voltages and storing them. The data is received from in-build 8-channel ADC of ATmega32. Here, ATmega32 is used for data collection and microSD interface. Aim of this project is to present a way to store a large quantity of data into microSD card in files with FAT32 format.