# Electronic Dart Scoreboard...

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#### crudeau

##### New Member
Hey all! I'm looking to build an electronic dart score board. Something that does the same function as the dart master III. **broken link removed**

They are like 300 bucks, but we want it to look a little different, but provide the same function. I'm very good with my soldering iron, as well as the fabrication. But I have no idea with the actuall programing and circuit design. I have down some flash programing on my xbox's and worked with an eprom programmer back in my cisco upgrade days.

So far I have the aluminum to design my housing, and installing the lcd panels and switches are pretty straight forward. But I have two questions,

#### vne147

##### Member
1. Can I make the circuit and controller for less then the cost of \$300?

Absolutely.

2. Is there anyone who can help with the programming.

yes.

From a cursory glance at the link you provided it wasn't clear to me what capabilties this thing has other than just keeping score. Does it detect where the darts land and add the appropriate amount of points automatically or do you have to manually enter the points using the keypad? How do you increment the hits in the various areas (i.e. 15,16,17...)? It also, said you could play against it. What does that mean? What are the extra 7 segment LED displays for? If you want to reproduce the functionaltiy of this thing exactly, you'll have to share some more details on how it works. If you are not interested in making a carbon copy of the thing, you'll have to define a little better exactly what it is you want it to do.

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#### crudeau

##### New Member
I have no interest in playing against it. I just want it to score cricket and 301, 401, 501 games. For all games the left would be the away team, and the right would be the home team. The board is just a scoreboard, doesn't have to detect any darts.

Here's what I need it to do...

For 301, 401, and 501...
The board has to start from one of the above numbers and count down to zero based on the numbers entered on the keyboard. So lets take 301 for example. On the example board I sent you, you would game type 301. It puts 301 on both sides of the board. First team throws a triple 19 and a single 16. You would hit 73 on the calculator and then the left score button. This would automatically subtract the 57 from 301. So now the away team would show 228 remaining and under it would 73 which is the last score entered. You would do this alternating back and forth until some hits zero and wins. 301, 401, and 501 are all like this, just have to start from a different number.

Cricket is a little different. Hopefully you know how to play it so it's easier to understand. This is the 7 segments at the bottom. So you would start by setting the board to cricket. Object of the game is to be the first player to hit 3 of the 7 object numbers first. 20,19,18,17,16,15,Bull. Once you have 3 of one of the object numbers, you begin to score that amount of points. Say I go first and hit a triple 20, and a single 20. I would now have 20 points since you have none. So on the board you would hit the 20 button 4 times and hit the right score button. now the board would have the three leds next to 20 lit and show 20 on the top of the score board. Now heres where it gets tricky, so you throw the same 4x 20's. the board should know that you only get 3 and no points, since I already have them closed. It works this way for all numbers including bull.

Does that make sense? The example I sent of the Dart Master III has a practice mode which is where it just automates an opposing team on the score board. I don't need that feature, just want it to keep score.

#### vne147

##### Member
I don't get that magazine. With the help you can get I don't think you would need to buy it but it may still be useful if you decide to.

I understand how to play all the games you mentioned. Programming a PIC for them will not be difficult. However, you don't immediately need to get into the programming. If I were starting this project the first thing I would do would be to figure out how many LEDs, pushbuttons, 7 segment displays, etc, the project is going to require. Basically, you need to figure out how many I/O pins you'll need. That will be necessary to selecting an appropriate PIC. Once a list of all the peripheral components is made, and a PIC is selected the interface circuits can be designed. After that, I'd start programming.

So, figure out how many peripherals the project will require. Then we can proceed. A diagram would probably be more useful than a simple list. It's not necessary at this point to show all the electrical connections. Just make a simplified diagram showing all the peripheral components with labels and explanations of function where necessary.

#### crudeau

##### New Member

It's going to be the same as this but with bigger leds and bigger lcd screens for the top scores. I would like for the red button on the keypad to be an undo button. So it removes the last score. Otherwise all buttons are the same, just going to be laid out different. The cricket leds are going to be 5mm instead of 3mm.

I can do a diagram, but what program is the best/ easist to use?

#### vne147

##### Member

It's going to be the same as this but with bigger leds and bigger lcd screens for the top scores. I would like for the red button on the keypad to be an undo button. So it removes the last score. Otherwise all buttons are the same, just going to be laid out different. The cricket leds are going to be 5mm instead of 3mm.

I can do a diagram, but what program is the best/ easist to use?

The program you make the diagram in doesn’t matter. You can use paint, Photoshop, draw a picture and scan it in, etc. Whatever you are comfortable with. The important thing is to clearly represent all the peripheral components that will need to be interfaced with the microcontroller. You will also need to clearly and thoroughly explain the function of each peripheral.

Some things are self-explanatory like when to light the LEDs that correspond to the object numbers. Other things are not so self-explanatory like the buttons labeled “Cricket Score Enter Buttons”. I assume that when you push the button, it turns on additional LEDs one at a time to represent 1, 2 or 3 hits for each of the object numbers. But, there is only one button for both the home and away sides. Does pushing that button increment the home side, the away side, both? I don’t know and it’s not readily apparent by looking at the picture you posted.

Other things that I was unsure about is the center LED display labeled “Score or Game to be Entered”. Does that just say 301, 401 or 501 depending on what game you are playing? If yes, how do you select the game? If that’s all it does, is it really necessary? It would simplify things to replace that with a 3 position selector switch.

Also, there are two LED displays for each side, the previous score and the current game score. The current game score is pretty straightforward but what is the previous score. Is that the score from the previous turn or the previous game? Why is it necessary to show that?

Those were the only things I had uncertainties about right away but other questions will surely arise as you get more into the project

You will need to get into the nitty gritty, go through each part of the scoreboard, figure out exactly what’s going on, and document it. You should approach your explanations and the information you provide with the level of detail that will be required when writing the software. You wouldn’t be able to simply write a program that says, “Make it look like the picture” and neither can I. At least we can’t do that yet.

Also FYI, the displays that you are referring to as LCD displays are actually 7 segment LED displays. Check it out:

Seven-segment display - Wikipedia, the free encyclopedia

#### crudeau

##### New Member
I'm working on a diagram, I figure I will draw it, then scan it. seems easist.

The cricket score enter button is how you enter the score for cricket. Say you throw a triple 18 you would tap the 18 button 3 times and then hit the home or away score button, for which ever team you are on.

The calculator style pad is for '01 games only, and the led buttons are for cricket only.

so basically if you are playing an 01 game then bottom led's aren't used. You would set the score board up for an 01 game. Then you add the darts thrown up and punch that into the keypad, and hit either the red or blue side to have it subject it from the total. Both sides of the remaining points on the top screen and the last throw under it.

Middle lcd window is what game you are playing. I would want that white reset button to be the game selection button, 301, 401, 501, CRT

I will post a drawing up, and try to be more specific with what does what once I have my design laid out. I think I will have all the same buttons and components as the example, but different colors and sizes.

#### crudeau

##### New Member
I have the diagram, just have to figure out how to post it up. It's pretty much the same as the dart master 3, just adding a screen above the "current score to be entered" lcd. The new screen stays showing what the current game is.

I'm also moving the reset button to the top of the board, The blue botton on the number pad is current current score, the red number pad button is an UNDO button, it will remove the last score, and the red number button is an undo button, that can go back 2 times.

otherwise all buttons are the same.

#### crudeau

##### New Member
Can I just email you the sketch that I have? Also I'm thinking the next step should probably be to figure out all the lcd screens, switches, leds, and keypad. That would be what would figure how many pins. From there, I can assemble everything and know exactly what would be required from the controller, as far as pins/connections.

#### vne147

##### Member
Can I just email you the sketch that I have? Also I'm thinking the next step should probably be to figure out all the lcd screens, switches, leds, and keypad. That would be what would figure how many pins. From there, I can assemble everything and know exactly what would be required from the controller, as far as pins/connections.

I PM'ed you with my email address.

#### vne147

##### Member
I got your diagram and I posted it here for referrence. After looking at the diagram and adding up all the I/O functions I came up with 146. So, if we were to provide each function with it's own dedicated I/O pin we would need an MCU with at least 148 pins (146 + 2 pwr pins). I have never worked with that big of a processor before and moreover, it's not necessary. There are things we can do to accomplish the functionality required for this project while using a much lower pin count MCU. One trick we'll use is multiplexing.

For the cricket portion, there are 7 banks of 6 LEDs. We can use the same 6 I/O pins for all 7 banks and cycle through them so fast, the eye will be unable to tell that only one bank is actually on at any one time. This is a common thing to do and will not be hard to accomplish.

For the 7 segment displays used for the '01 games we will use driver ICs like this one:

http://www.datasheetcatalog.org/datasheet/philips/SAA1064.pdf

We will use four of these driver ICs (one for each display). The MCU will communicate with the drivers via an I2C bus. I2C is a communication protocol that many MCUs have built in fuctionality for. By doing it this way we will only require 2 I/O pins to drive all 4 displays.

After considering the tricks I discussed, in the end we will need 35 I/O pins. There may be a few more things I can do to decrease the I/O pin requirement, I'll have to think about it but there are readily availible and cheap 40 pin MCUs out there that I have worked with before.

I'll need a few days to come up with a schematic. Once that's done I'll post it here. You can make sure you understand what's going on before we get into the programming. It will also give others a chance to chime in before you build it.

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• dart board..jpg
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#### crudeau

##### New Member
The only thing I see that wasn't mentioned was the fifth lcd window, in the middle. The one that just displays what '01 game or crt that you are playing.

Everything else sounds perfect to me. I'm very excited to get started on this. The only thing that would be cool to build into the screen would be the lcd screens that can be mouted remotly. As in this board is mounted to the left of the dart board, and then there could be two large displays above the dart board showing the current score and cricket numbers. That part isn't important to me yet, but I just want to make sure the design has the available contacts or pins for it in the future.

Thanks for all you time. I can't wait to start building.

#### vne147

##### Member
The only thing I see that wasn't mentioned was the fifth lcd window, in the middle. The one that just displays what '01 game or crt that you are playing.

Everything else sounds perfect to me. I'm very excited to get started on this. The only thing that would be cool to build into the screen would be the lcd screens that can be mouted remotly. As in this board is mounted to the left of the dart board, and then there could be two large displays above the dart board showing the current score and cricket numbers. That part isn't important to me yet, but I just want to make sure the design has the available contacts or pins for it in the future.

Thanks for all you time. I can't wait to start building.

FYI, the displays you keep referring to as "lcd" screens will actually be 7 segment LED displays.

If you want to drive external displays eventually, we can make sure the final build has external connectors for later expansion.

The center LED display that will show the game mode will not need to be driven by the micro controller. This part will work by using a 2P4T (2 pole, 4 throw) switch. One pole will connect to 1 of 4 different I/O pins on the MCU. The MCU will be programmed to check which input pin is HI and then change the game mode accordingly. To show the game mode on the display, the appropriate segments on the display for each game mode will be grounded through the switch. Also, since you want to display "CRT" for cricket a regular 7 segment display won't work. The 7 segment display is for displaying 0-9 A-F and some other letters. To display all letters like CRT, you will need a 14 or 16 segment display. The concept is the same at the 7 segment, it just has more.

Check out a 14 segment display:

Fourteen-segment display - Wikipedia, the free encyclopedia

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#### crudeau

##### New Member
excellent. so I think everything is accounted for. So i guess now, it's a matter of you designing the schematic. From there I go and order everything. I figure once I have all the parts I will talk to machine shop buddy and get the case made. While he is doing that I can bread board everything.

So I guess it's the schematic and then figuring out each individual component. I've been browsing the internet checking out a few different sites that have everything I think I would need.

I'm so excited that the plan is coming together. And thank you for all your help.

#### vne147

##### Member
Here is a prelimenary schematic. It probably needs some tweaking and there might be a few errors but it's good enough for you to start looking over and learning how the circuit will work. Ask questions if you don't understand something.

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• scoreboard.JPG
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#### crudeau

##### New Member
looks good to me. I think one thing that was forgotten, was the reset switch. I was thinking about putting this switch uptop out of plain view, but it be the button to hit after the game is finished and you want to start up another. Unless you think the game select should also do that. Like a press and hold to start the game over, when there is current data entered. if there is no data entered, then you just keep tapping the button to select the game. what ever is easier to program i guess.

Otherwise it looks awesome to me. And the resistors and such all make sense to me. What's the next step? Probably for me to figure out exactly what screens, keypad, and buttons i want? Then send you links to make sure they line up with the schematic.

#### vne147

##### Member
looks good to me. I think one thing that was forgotten, was the reset switch.

I didn't include a reset switch in the schematic because you didn't put one in the diagram. It would not be a problem to add one. There are a few free pins. When hitting the reset button, would you want the current score only to be set to zero or the current score and last game score? Also, would you like the scoreboard to keep the current and last scores even when unpowered?

I was thinking about putting this switch uptop out of plain view, but it be the button to hit after the game is finished and you want to start up another.

Where you decide to mount this switch will be totally up to you.

Unless you think the game select should also do that. Like a press and hold to start the game over, when there is current data entered. if there is no data entered, then you just keep tapping the button to select the game. what ever is easier to program i guess.

The game select switch as shown in the schematic is a 4 position slide switch, not a push button that cycles through games modes upon subsequent button pushes. The slide switch will be easiest. In fact you don't even really need the 15 segment LED displays to show the game mode. You could just tell the game mode by the position of the slide switch. It doesn't hurt anything to have the display. It doesn't take up any additional I/O pins it will just make the project slightly more complicated and expensive. If you're dead set on having a pushbutton to select the game mode instead of the slide switch, it can be changed but it would add some complexity to the programming and the circuit.

What's the next step? Probably for me to figure out exactly what screens, keypad, and buttons i want? Then send you links to make sure they line up with the schematic.

Yes, go decide what 7 segment displays and 15 segment displays you want and send me links. Make sure that there are online data sheets available. If there is no data sheet, the only way I would have to know how the thing works would be for me to physically have it. Make sure you select common anode type displays.

For the keypad make sure you select a matrix type keypad. It should have 7 pins. There are other types of 12 key keypads that have 12-14 pins. They will not work with the project as it is right now.

For the slide switch, something like this would work:

G-1138S-1110 CW Industries Slide Switches

BTW, what part of the country do you live in?

#### crudeau

##### New Member
I live in North Jersey.

I don't mind the slide switch, I would like the display though that shows the current game. This is for my local bar. We have a board in the back room where we all hang out. So i'm trying to go a little over the top with the external displays, but I'm the one financing it, and I don't have a ton of money. Otherwise I would just buy the dart master. Plus, it is way cooler to make it yourself. I will look into the displays this weekend and post up what I want to get. The power thing would be cool to have, where it remembers the score in a power outage, but isn't necessary if adds to much effort.

The reset button is a total clear button. Hitting completly resets all scores screens. Since there is a slide switch for game type, it would stay the same game. Just reset everything to defaults.

#### crudeau

##### New Member
I seem to be having a hard time finding a good source for the displays. I can only find 1/2" ones. They are fine for the lower "last score entered", but I am trying to find 3/4" or 1" for the upper displays. Does it have to be 3.5 or 4 segment? I can find them in single digit and they seem to be "stackable" or allignable. not sure on the correct term there. Any insight on where to look? I am hoping for blue leds but red or white would work.

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