Working the Arduino I/O Ports in BYTE chunks

[State Machine]

In case you need to work with more than just one PORT bit at a time, here is some good information on I/O PORT manipulation on the Arduino development platform.

http://arduino.cc/en/Reference/PortManipulation

This is also applicable to the read or write of any of the Atmega MCU hardware control registers.

For example, here is a section of code below I needed to write to control TIMER 5 of an Atmega1280 chip on the Arduino MEGA board to output a 2500 Hz, 500 ns pulse on an I/O port bit. You will need to reference the chip data sheet in order to understand what the actual data does:

// timer/counter 5 setup
TCCR5A = B00101001; // Phase and frequency correct PWM change at OCRA
TCCR5B = B00010001; // System clock Select (16 Mhz)
OCR5A = 3200; // Set to 2500 Hz
OCR5C = 4; // Init to .125 % (500 ns PW)

Hope this helps !

Happy Holidays !
Bill

[elmegil]

Thanks!

[State Machine]

Your very welcome. I have seen this question come up here and there and though it was useful information. I have an example of a FIFO memory read routine I wrote and will post that as another example.

Sure beats reading in PORT bits one by one in a loop and assembling a byte in software (SLOW !!) when you can just read the FIFO a byte at a time and get on with processing the data.

Bill

[cappy2112]

[State Machine]