I'm very new to the whole Arduino world, as its currently my third day. I'm currently doing the projects in the starter kit and have a question when going from one project to another.
So let's say the Arduino has a Sketch programmed. Now you unplug it and change the connected circuit and also program a new Sketch fitting to the circuit change. In order to get my sketch on the Arduino I need to connect it again, but then the old program kicks in. What happens if the old program somehow "clashes" with the now new circuit? For example a pin is supposed to be an input pin, but now its still outputting because of the old program?
As I said I'm really new to this but for me this sounds like a possible source of error that could lead to unexpected currents flowing in my new circuit or even shortcuts because of an old program.
This is unlikely to be an issue - but it is conceivable you could damage the Arduino. ( e.g shorting out a digital input still connected to a switch that becomes an output)
it is good practice to disconnect anything connected to the pins before uploading a new sketch . You can then power down and add the external components and power up.
If you were to “park up “ your Arduino , you could, if you want, just upload a blank sketch ( the sketch you see when you open a “new” sketch from the IDE) , so next use you can be sure it’s ok to go .
So .....if say you had the blink sketch installed and you’ve then wired up the nuclear missile trigger , then you dont accidentally fire it off whilst uploading the new sketch.