I want to make test console for my robot, and i want to use analogRead and buttons, so when i click a button arduino executes command. Code is not a problem here, i just want to know how big of a voltage can i put over button to arduino analog in pins so i don't burn board. I don't have schematic so i don't know how it reads voltages, does arduino pull any current from power supply when analog reading, because i have one old server psu which provides a lot of current.
The robot runs at 5V which means for analog, you can input anywhere from 0-5 VDC.
The robot runs at 5V
I think he meant to say, "The Arduino runs at 5V."
does arduino pull any current from power supply when analog reading, because i have one old server psu which provides a lot of current.
No. The arduino inputs are ~100 Meghoms or more, so essentially no current flows. Except... If you exceed Vcc or go negative, the internal protection diodes will conduct and you can get LOTS of excess current and "bad things" can happen!
There are ways of handling/reading higher voltages so let us know if you need to do that.
Ok, you both are saying that i can connect button on 5v, in between wire wire that will go to analog read pin so when i turn on the button i read voltage from there, and i don't need any resistors for that, just wana be sure really don't want my arduino to disappear in smokes.
So long as that's the same 5V as the Arduino uses, yes.
If the wire is long you might have to worry about noise pick-up on the wire, for instance it shouldn't
run near the high current things like motors and motor-drivers. All signal wires should run alongside
a ground-return wire (many signals can share one ground wire of course).