[Part 1] Arduino Data Logger

This is the first post in a series in which I'll document the development of an Arduino-based data logger. The requirements for this data logger are:

• Data to be logged is a 4-20mA current loop signal (2-wire) from a sensor (using 4-20mA for analogue measurement is an industrial automation standard);
• Sensor requires a 24VDC supply (I'll be using a 240VAC-to-24VDC transformer plug pack to provide the 24VDC so there will be no mains supply work required);
• Whole system to be contained in a box that can be sealed up and made "weather-proof".