Trouble connecting Vcc2 to SN754410
October 24, 2009
I've tried looking around a bit and expect this to be a fairly basic question, but nonetheless I still can't get it to work. Basically I have an arduino connected to a SN754410 motor driver powering a lego motor. This all works fine until I try to use a second power supply (9V battery in this case) instead of the arduino's 5V output. Here's the current setup:
Note that the arduino is running off of USB power.
I'm not sure exactly how to make it run - I tried putting an led & resistor in series with the 9V as well, and in doing so I found that current is being drawn. Also, testing the 9V with the motor (directly wired) works fine. What connection am I missing to get this working?
Also, I read in a few discussions around here that the SN754410 doesn't have kickback protection diodes - where would I add these diodes? Between the +5 and Vcc?