Hi! Where can I find basic definitions and the relationships between
and the difference between serial, analog, and digital (like on the Arduino board pin labels???) and the difference between dc and ac? Thanks so much!!
Ohms are a measure of resistance that something applies against the power flowing.
ohms = votage / current, where voltage is the voltage drop between the contacts
of the component being tested.
Voltage is a measure of potential difference between two contacts. That is, the
ammount of push that the electrons are experiencing between two points.
voltage = current * resistance
Amps are measurements of current. They measure the ammount of electricity that
current = voltage / resistance
Serial is when digital 'bits' are sent one after another. A bit is either a 1 or a 0, and
represents a number.
Digital uses just two numbers - 1 and 0 - to represent decimal numbers. 1 is when a pin is
on, and 0 is when a pin is off - high and low. In digital, each bit of the number is either
one value, or another value. Nothing exists in between.
Analogue is when something changes smoothly. Rather than just being on or off, it can be any
This is when all the bits are sent at the same time, through seperate wires. Altohugh you did
not aks about it, it makes sense to add it in.
For voltage, current and resistance, imagine a water pipe. The width of the pipe is the resistance
in a component - thinner pipes let less water flow, so have a higher resistance. The current is simply
the ammount of water flowing through the pipe, and voltage is the ammount of force pushing the water
through. as there is only force on one side of the pipe pushing the water, and none at the other, we
call the non pumping side '0v', as there is 0 volts of force pushing or pulling.
Stairs are a good analogy for digital. When you are on a stair, you are either up on one stair, or down
on the other. You do not float around in between.
For analogue, a ramp is a good analogy. You can be anywhere on it - completely up, in the middle,
all the way down, or somewhere else. This is like an analogue voltage.
For counting in binary, check here: http://www.glassgiant.com/geek/count_to_31_on_one_hand/
Hopefully someone can correct me if I am wrong.
Hope it all helps!