Why do you use port manipulation on Arduino?
In this article we are going to examine Arduino I/O pins in more detail by using “Port Manipulation” to control them in a much faster manner than using digitalWrite ()/digitalRead (). Why? Speed! Using this method allows for much faster I/O control, and we can control or read groups of I/O pins simultaneously, not one at a time; Memory!
How are pin numbers mapped to ports on Arduino?
For a complete mapping of Arduino pin numbers to ports and bits, see the diagram for your chip: ATmega8, ATmega168. (Note that some bits of a port may be used for things other than i/o; be careful not to change the values of the register bits corresponding to them.)
How many ports are there on an Arduino board?
The chips used on the Arduino board (the ATmega8 and ATmega168) have three ports: Each port is controlled by three registers, which are also defined variables in the arduino language. The DDR register, determines whether the pin is an INPUT or OUTPUT.
How does the port register work on an Arduino?
Each port is controlled by three registers, which are also defined variables in the arduino language. The DDR register, determines whether the pin is an INPUT or OUTPUT. The PORT register controls whether the pin is HIGH or LOW, and the PIN register reads the state of INPUT pins set to input with pinMode ().
How are DDR and port registers related in Arduino?
DDR and PORT registers may be both written to, and read. PIN registers correspond to the state of inputs and may only be read. PORTC maps to Arduino analog pins 0 to 5. Each bit of these registers corresponds to a single pin; e.g. the low bit of DDRB, PORTB, and PINB refers to pin PB0 (digital pin 8).
What are the parameters of digitalWrite on Arduino?
It takes two parameters, just as digitalWrite does: uint8_t pin is an integer ∈ [ 0, 13], standing for the desired digital pin of the Arduino. uint8_t x is the second parameter which has only two legal values, namely { 0, 1 }. The value 0 is equivalent to low and 1 to high. Any other value might alter other pins too, so be aware.