is it possible to measure both voltage and current with an arduino, not at the same time that is…i want to measure from 1.5 to 24 volts DC and 0 to 1000 ma…how would i go about it with hardware
Many micros including the Arduino have an ADC (analog to digital converter) that will convert a voltage into a number for you. You apply the voltage to a pin, and start a conversion in software. At the end of the conversion you get your number. That number is scaled between 0 and a maximum (ie 1024) based on the voltage inputs position between ground and a voltage reference (often the same as the power supply to the micro).
For an Arduino this means your voltage input needs to stay between 0 and 5v. If you apply 24V to the Arduino, you will likely destroy it. So you need a way to scale down your voltage into a safe 0-5v range. Read up on resistor dividers for this purpose.
Measuring current is an issue as micro do not sense current directly. Therefore you must convert current to voltage in some way. Possible solutions include small shunt resistors, measuring side effects of the circuit, current transformers (for AC circuits), and hall effect sensors.
Without knowing your exact application, it is not possible to recommend a proper current measuring system.
Yes it is possible.
For the voltage just use a resistive divided to keep the voltage within the MAXIMUM limits of the input pin.
For current use Ohm’s Law for an I to E converter. (Hint: voltage drop across a resistor is proportional to current).
An op-amp with gain is usually required.
There is lots on the web so do some googling then come back here with more questions.