I have looked but in the supplied documentation but there is nothing about how to turn the UNO on or off apart from plug in the USB/Unplug the USB
What is the correct procedure to avoid damage to the UNO or any connected componets.
The reason I ask is that after I had do the initial LED example from the ARDX starter set, I unpluged the USE from the UNO and then built up the "Spin Motor Spin" example. I downloaded the sketch from the ardx site and put it into the IDE, pluged in the USB and the UNO started to pulse the motor. This was before I had uploaded the new sketch so I presume that the UNO on boot up ran the previous sketch which was pulsing LED.
This got me worried that if I had an incompatible sketch with the new built circuit then something could go wrong when power is applied before new sketch upload.
Can some one help and tell me..
Correct procedure to power the UNi and not run anything until a sketch is uploaded.
Correct procedure to power down a UNO without just janking the USB out.
I'm new too, but as far as I know, there is no way not to run a sketch, if the Uno is powered.
That means, if you don't want your Uno to do anything, just unplug it. As soon as you power it again, it will run the last sketch uploaded.
Don't worry about damaging your Uno, it's pretty robust
Hold down the reset button for a couple of seconds whilst plugging it in. This seems to stop the sketch from running whilst waiting for a program to be uploaded. I don't know if it is a bug or feature of the Uno bootloader, in any case it doesn't work on a Duemilanove.
In future, upload Blink or BareMinimum before wiring up your Arduino
Well, you could add reading a button to your hardware, press & hold it while applying power. Have sketch not do anything but apply non-damaging outputs until the button is released.
It's always risky to wire up new circuits to an arduion chip that might have an existing sketch in it from a prior project. What I do when I'm finished playing with a sketch/external wiring is the last thing I do prior to unplugging it is to upload the simple blink sketch to the board. That way the next time I power the board up I will see the pin 13 led blinking at one second rate, I know it's safe to unpower and start wiring up whatever new project or testing setup I'm working on. That assumes that I never use pin 13 as a input pin to a switch for fear of shorting out pin 13, which is a policy I try to adhere to.
