Interfacing with a dartboard.

Forum 2005-2010 (read only) Hardware Interfacing
1

I have been trying to find a solution to integrate my electronic dartboard to a PC. It seems the arduino might be it. I am a software person, so I am looking for help with the hardware.

The dartboard works like an 8x8 keypad matrix. Two films sandwich a thin separator. Take a look at the pictures here.

That dartboard uses an 8x11, mine uses an 8x8 matrix.

I saw a circuit for this sometime ago. From what I understand is I would set 8 pins to high with the pull up resistor, they would get the top film. The bottom film would hook up to 8 pins that are set to low. When a dart hits it should create an interrupt and then I would need to poll the pins. So when I do this for the pins set to high I would be looking for the low, correct? Visa versa on the other side?

Now, there is the question about having enough pins. I know the common arduino has 14 digital pins and 6 analogs that can work like digital. If I hook up the arduino through usb does that only take up 2 of the pins?

2

If you hook up your Arduino to your PC via the USB connector and use Serial.print() to communicate between them, then yes, digital pins 0 and 1 are used for that connection. Looks like you have enough pins left for your matrix, so I would say you are a go on that point.

3

Now, there is the question about having enough pins.

Getting more pins on an Arduino is easy. There are many ways to go about it from shift registers to port expanders and multiplexing. Have a look here for some ideas:-

http://www.arduino.cc/playground/Main/InterfacingWithHardware