I'm new to arduino. I want to get data from ms excel spreadsheet to my arduino code and write conditions according to the data which I receive from that spreadsheet. So can you please help me out and give any suggestions so as to how to communicate between my arduino UNO board and pc.
The Arduino communicates with a PC via a serial com port connection.
You will need to figure out how to output data from Excel via the serial port. I've never heard of anyone doing that.
via Processing?
Excel has an option to export the data as a CSV format, from there it is a simple case of making a Visual Studio form using the Visual Studio Serial library and File reader, I recommend using C#, it almost the same as Arduino C. Then you just need to make an Arduino code to read the serial data using the header each time and place the following data into an array.
I actually use Excel to write code. Lists of EEPROM variables get turned into pieces of code to be pasted into specific parts of the Arduino program.
There is a way of getting Excel to talk to the Arduino. Usually it's used for data logging but it can be done in the other direction. PLX-DAQ is a reasonably complete solution. There are a few tutorials online showing you how to to it in VBA programming.
I use PLX-DAQ for logging data from the Arduino, but have never explored how it might work in the other direction. Here is the latest version.