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Topic: Arduino Pin - Questions (Read 195 times) previous topic - next topic

gnusso

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,

Graynomad

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
Rob Gray aka the GRAYnomad www.robgray.com

holmes4

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

Mark

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

retrolefty


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

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