Is it ok to supply your breadboard with one PW supply and the Arduino with your your computers USB port.
I want to run a output pin to the base of a NPN transistor.
The transistor is powered by an external PS to the collector through the load.
An input pin also uses a ground from the external PS to see a LOW.
Can most ICs work with VCC @ +6-7V so I can just use the same external supply for the Arduino and the bread board?
Is it ok to supply your breadboard with one PW supply and the Arduino with your your computers USB port.
As I understand it, that's exactly what you should do 8) .... just remember to link the grounds together.
Have a look here
hendo:
Can most ICs work with VCC @ +6-7V so I can just use the same external supply for the Arduino and the bread board?
That's an incredibly dangerous generalization to make. There is no rule of thumb for "ICs" because they can contain virtually any circuit.
The only way to know is to look at a components datasheet.
As an example the ATmega328's absolulate maximum supply voltage is 6V.
OK thanks I won't run my ic's @ 6V
Why dose the Arduino board require this to run? Seems odd
Tieing grounds together is what I needed to here, but I thought this would be dangerouse because there might be current flow between the two all the time.
No the only time current will flow is when you are controlling the transistor, that's what the ground thing is... a return for the control current.
Bob
hendo:
Why dose the Arduino board require this to run? Seems odd
Because there is a regulator between the Barrel Jack/Vin and the ATmega chip to regulate down to 5V.