Arduino Pin - Questions

Hi Folk, in project with Arduino Uno Rev.2 I'd like to use:

  • Display ( 7 pins used )
  • Virtual Wire ( 2 pins used at least )
  • RTC ( 3 pins used )
  • Keypad ( 7 pins used )
  • Led ( 1 Led optional )

In total should i use 20 pins, so from my understanding is quite impossible do this with Arduino Uno because have 14 I/O, related this I thinks is possible pass to Arduino Mega 2560 rev 3 or Arduino Due.

I'd like to know if : - Is make sense use another arduino ? - Is possible use the same sketch develop for Arduino Uno just change the board with Arduino Mega 2560 rev 3 or Arduino Due ?

thanks in Advance Gnux,

The Uno has 20 IO pins because you can use the analog pins as well.

However there are sometimes issues with pins 0 and 1 as they are connected to the USB chip.

You could also use a serial display to save 6 pins.


Rob

You could use I2C for both display and keypad and and save 10 pins.

Mark

Thanks for the information, how I can use I2C for display and keypad ?

I can use in meantime for Real Time Clock also ?

Thansk for the the support, Gnux

gnusso: Thanks for the information, how I can use I2C for display and keypad ?

I can use in meantime for Real Time Clock also ?

Thansk for the the support, Gnux

First you would have to aquire a display, keypad, and RTC that all utilize the I2C method of communicating with a I2C master (the arduino controller). All the I2C devices wire to the same I2C clock and data pins on the controller. Each I2C device has a unique device address which allows them to share the bus and allow the master to work with each and all attached devices one at a time. I2C allows up to 127 devices to share the I2C bus.

Lefty