I read that I can power both Arduino Uno and the standard Motor Shield that fits on top of it by attaching the + and - of a battery to the shield power pins + and - and keeping the power jumper of the Motor Shield in.
In my case, whether I keep the power jumper in or not, I always need to keep my Motor Shield connected to a battery and my Arduino Uno connected to another power (USB for example) to get it to work. Am I missing something?
Something that may have caused this is that the first time I used this setup I had Arduino connected to computer USB, and I connected the power the opposite way to the shield, with the power jumper in. In a couple of seconds the shield battery wires got very hot and I immediately discovered my mistake and disconnected them. May this have broken a certain "fuse" in the shield? I have another Arduino Uno so I tested with it and I got same behavior, that's why I'm suspecting the shield may have been damaged, and not the Arduino Uno.
Motor power is connected to V-in of the Arduino via the jumper.
If you have connected a negative voltage to V-in, you might have fried Arduino's 5volt regulator.
Test this by running e.g. the blink example with a 9volt battery connected to the DC socket or V-in with USB cable and shield removed.
Leo..
If I connect my rechargeable 9 volt (actually 7.5 volt) battery pack to the power plug, blink works well, but if I connect the + to VN and - to GND nothing works. Same for both my Arduino UNOs, does that mean both of them have broken regulators?
Also, I measured the voltages on 3.3 and 5v pins when I connect power directly to the power plug. One board gives 3.3 and 5 readings as it should, the other board gives 3.3 and 7.1, does that mean only the last one has broken regulator?
What does it mean if the regulator is broken? Do I need to throw this board away so I don't damage anything that will be connected to it in the future? anything on it worth salvaging?
mokdadali:
If I connect my rechargeable 9 volt (actually 7.5 volt) battery pack to the power plug, blink works well,
but if I connect the + to VN and - to GND nothing works.
Same for both my Arduino UNOs, does that mean both of them have broken regulators?
I assume you mean the DC socket.
What do you mean with "VN"
mokdadali:
Also, I measured the voltages on 3.3 and 5v pins when I connect power directly to the power plug. One board gives 3.3 and 5 readings as it should, the other board gives 3.3 and 7.1, does that mean only the last one has broken regulator?
What does it mean if the regulator is broken? Do I need to throw this board away so I don't damage anything that will be connected to it in the future? anything on it worth salvaging?
7.1volt on the 5volt pin means a damaged regulator.
This board can only be used on USB power (PC/laptop, 5volt cellphone charger, etc).
Don't use with motor shield with jumper on.
Leo..
"VN" is what is printed on my Arduino Uno board above the Analog pins and under 5V, RES, 3.3V, 5V, GND,GND. I guess the Chines manufacturer dropped the I in VIN
Thanks for the instruction, I will only use it with USB 5v only
So now I am using the "good" Arduino UNO with the motor shield, but as stated in my original question, I still cannot power them both with the same battery connected to Shield power pins, no matter whether power jumper is on or taken off. Why is that?
