if you want to measure dc current just use a low ohm resistor thats in series with with your gear and measure the voltage over the resistor with mcu or other komponents, its very simple
best regards
Yes sir, I agree with sphinx.
Got this from futurlec,
0.1ohm 5W 5% Wirewound Resistor ( US$ 0.2 each )
For your 2 Amps the dissipated power ( heat ) would be in the range of 2*2x0.1 = 0.4 Watt and the Voltage drop 2x.01 = 0.2 Volt
Used these on output line of Battery chargers, no problem at all.
Greetings
Francisco