This project is used to log the accelerometer's value over a couple of years at 2 samples per minute. This is to verify if we can measure the centrifugal acceleration of the earth on its orbit around the sun.

Material needed:

• mbed LPC1768
• mbed application board (http://mbed.org/cookbook/mbed-application-board) Includes an accelerometer, a temperature sensor and other goodies
• RN-XV WiFly module from Roving Networks (bough by Microchip) The WiFly module is still available on ebay. This module is only used to get the current time via NTP
• cable USB A to B mini
• a USB memory stick to store the data
• a power supply to power the board for the entire time of the data acquisition. Use a 6 to 9V wallwart on a UPS.

Power requirement: 6V-9V, 150mA. Duration of acquisition: 36 files * 100000 samples * 30 sec = 30000 hours = 1250 days = 3.42 years

The number of samples, the sample time and the number of files can be modified easily. The code is short and well commented.

Network requirement: access to the local network via wifi (only for getting current time) access to a NTP server

Successful data acquisition will end with this message on the LCD: "End of data acquisition"

To abort the data acquisition without risking data corruption, press on the joystick button for about 30 seconds. A message "Aborting, USB Flash can be removed" will be displayed.

Place the module in a locked or unattended space.