I have a project and wish to choose the correct battery back for it such that it will last the required amount of time between each recharge of the battery pack. I am using an Arduino Duemilanove with various attachements and shields.
I can measure that the draw on the project at the point the USB connects from my PC to the Arduino board (by attaching the multimeter to the Vcc and GND solder points on my Arduino board) which reads 5V DC as expected. Is there a way I can meausre the current (without any additional equipment) ?
I suspect somehow using Ohms law and measuring the resistance between two points would be the answer (knowing the voltage is 5V) but I can't work it out (as in where to measure) with my lack of any electrical knowledge.