I am following [this tutorial for a CNC laser engraver][1]. I have two stepper motors from some old DVD drives and two [L9110S H-bridges][2] to control them. I am now working on putting it all together and ran into some confusion when setting up the power supply for which I cannot find much information on within the guide. Could I connect the 5V at pin 2 of the RPi to both the H-Bridges to run the stepper motors or will I need to look at an external power supply for this? If external, what could I use? I have seen examples of 4 AA batteries in series, will this do the job? [1]: http://funofdiy.blogspot.co.uk/2013/10/a-raspberry-pi-controlled-mini-laser.html [2]: http://www.ebay.com/itm/350877288713?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649