How to connect 20 pins to Arduino UNO for OpenDart project

Hi there Arduino community :slight_smile:

I'm brand new to Arduino, but loves to mess around with electronics.
I'm following the project "OpenDarts" Project Link

But, I have an old Dartboard that has 20 pins, Arduino Uno only has 18 GPIO pins for me to use (I can't connect to #0 and #1)...

Would anybody be willing to help me ?

I bought a breadbpoard, I guess it's the only way for me to get this project working with the type of dartboard I have...

But I really don't know how to connect the breadboard, the jumpers, and how to ajust the coding to get the outpout from the breadboard...

Thanks in advance !

(deleted)

If you really do need 20 i/o pins, I'd suggest using a Teensy board.
There are several teensy boards to choose from (AVR vs ARM and 5v vs 3v) and they all have 20+ i/o pins.
The Teensy 2.0++ would give you 20 plus pins with lots of extras left over for other things.
https://www.pjrc.com/teensy/techspecs.html
https://www.pjrc.com/store/teensypp.html

I really like the Teensy boards as they are very small, and are breadboard and PCB mounting friendly.
And the AVR core code for digital i/o digitalWrite()/digitalRead() is 40 times faster than the AVR code supplied with the IDE.

--- bill

(I can't connect to #0 and #1)...

You can if you put a double pole switch between the incoming serial and the pins like I did for this MIDI project:-
http://www.thebox.myzen.co.uk/Hardware/MIDI_Shield.html

Oh WOW :)Thanks everyone for the answers.

Since I'm a begining noob, I'll go with the MEGA for now.

This project will definetly make me learn a lot :slight_smile:

Merci !

There's also ATMega324, 644, and 1284. 40 pin DIP and lots of pins but not as large as Mega2560. The only drawback is no official Arduino board for this so you need to get alternative board like Sanguino or get the chip naked and wire in Vcc, ground, clock, and resistor on reset to 5v and use another Arduino as ISP or something to upload sketch.

Seems like a Teensy might be easier to use than a Mega since you said:

I bought a breadbpoard,

since the Teensy boards are breadboard compatible which potentially allows easier prototyping than using a board with the "Arduino/Mega" form factor.

Also, the Teensy boards are small that it could potentially fit back into the original dartboard case.

--- bill

spycatcher2k:
Easy = buy a MEGA2560
Harder = Use shift in register chips e.g. 74HC165

It's funny that my post got deleted from this thread while my post was almost exactly the same.

Lennyz1988:
It's funny that my post got deleted from this thread while my post was almost exactly the same.

Nah, you relied to one of the OP's crossposts and that got deleted.

dannable:
Nah, you relied to one of the OP's crossposts and that got deleted.

Aah that would explain it.