Hi everyone. I've been having this issue the whole time I have been working with the Arduino UNO. I have Win 7 64 bit and I am connecting to the board on COM 3. I am using this for a robot so I have 3 sensors and 4 motors connected through other shields. At times I have had a few different power options but right now I am running a 6 AA battery holder and have had the same problems even with more power connected to it. I have always been able to connect the board at least for a short time (luckily long enough to upload code) but I do not have a serial LCD and need some way of knowing what the robot is sensing to debug my code but I am unable to do this because after a short amount of time the serial connection will die and I will get the "Com 3 not found" error if I try restarting the serial monitor. It does seem to work better with less sensors connected to it but it is not practical to unplug everything every time I need to restart. I have tried re-installing drivers but to no avail. It is a somewhat intermittent issue as I can reset the board and connected for a few seconds or more but I am never able to persistently connect. Any ideas?
at a first guess it sounds like your drawing too much current from the chip and its resetting
Thanks for the reply! That sounds like it could be the issue is there anyway around it other than temporarily removing sensors?
Instead of using Arduinos 5 volt to power the rest of your project, you could use another +5 volt supply.
I often use +5v and ground from my pc if a project uses more as USB can handle.