An SD Card can be used to log data continuously over time for various purposes, this project shows the design of a temperature data logger with menu control system. The ambient temperature is read every minute and stored in a file on an SD card. When the program starts, the user is given three options: Saving the temperature readings to a new file on an SD card, Appending the temperature readings to an existing file or Sending all the saved file contents to a PC The user will have to choose one option and then press enter to start logging data. This menu only accessible once when the program starts, if the user wants to choose another option, he/she has to restart the program by pressing the reset button.