Repository files navigation

This is an Arduino program to make a 6 bit DAC using anR2Rladder connected to thecorresponding pins on the Arduino.

The code is a slight modified version of a previously existing one provided byFIUBA'sprofessors from lecture "Introducción a la Ingeniería Electrónica", andcorresponds to the Final Group Project. The modification adds the ability to usepins from different ports instead of all the pins from the same port.

The ports are 8 bits registers that Arduino uses to internally represents theoutput pins. You can find which pin correspond to which port by looking on anyArduino pinout diagram, being the most common ports PORTB, PORTC and PORTD.

The code uses PORT manipulation since its faster than using builtin functionlike pinMode(), and thus improving the softness of the recreated wave by theR2R.

The following statements produce the same effect on the arduino output pins andshows the difference in speed of using builtin functions and port manipulation(Taken fromthis arduino forumquestion)

pinMode(5,OUTPUT);// takes 71 clock cycles (~4.430us@16Mhz)DDRD |=0b00010000;// takes  2 clock cycles (~0.125us@16Mhz)bitSet(PORTD,5,1);// takes  2 clock cycles (~0.125us@16Mhz)

Also assigning the new value to the port allow for multiple ports to be updatedon a single statement, for example turning on both pin 4 and 5 at the same timecan be done with the following statement

DDRD |=0b00011000;

For more information I suggest readingArduino Reference on PortManipulation