measurements for midterm

I set up a test rig to see how much current our circuit was actually pulling. I did this by connecting a 12V DC power supply through my multimeter (measuring current in mA) and connecting the (-) probe of the meter to the (+) pin of the arduino DC power input. If this sounds confusing, it may be because I am being too specific. In other words, I connected the multimeter in series with the DC power input of the arduino. This gave power to the entire LED circuit, and from there I was able to measure the total current pulled by the circuit. Why do this? Because I needed to know how much current a battery needs to supply in order to power the circuit, and based on that amount, I can see how long it will take for a certain battery to fully drain. As can be seen by the picture above, the average current measurement on this circuit (when the LEDs were about medium slow in sequence) was about 42 mA. It is important to note that the current pull through the circuit is greater when the LED sequence is slower. Why might this be? I think it has to do with the fact that the LEDs are turned on longer when the sequence is slower.

I chose a DC power supply over using a standard 9V battery because I couldn't get the battery to work right with the circuit. For some reason, the battery got unneccesarily hot when I tried to connect it in series with a 5V regulator and then the output of the regulator went to the power input on the arduino. I will look into this problem further tomorrow.