So if there is a pull-up resistor between a pin and 5V, how is that keeping the pin at 5V? Surely there is a voltage drop across the resistor?
Well apparently there is, but it is very very small because the resistor value would be chosen to be small compared to the impedance of the device the pin belongs to. It's like any voltage divider, Vpu = Vcc * (Rpu / (Rpu + Rdevice)). Where Rpu << Rdevice, Vpu ~ 0.
Anti-nuisance lawsuit warning: The purpose of these notes is to remind me, Zoegond, of stuff or to help me work stuff out. They may contain mistakes.
Quick
- ($a, $b....) = unpack("A2A7...", $packed)
- push( array, list )
