Working on making an arduino scoreboard need help with code

My boards ship with a bootloader and Blink installed. If you want more, I'm available for hire.

Like I said, that is confusing to be because I know basic arduino and a little circuitry. Do you mind helping me understand what you mean? I do not wanna spend extra money on this project. Now, with the code I have, what modification must I need if I want to use the suggestion I chose that I got from either KenF or PaulRB (I can’t remember which). Now I am confused on the best way to get the code to the display aka output. In the code right now, I do not believe what segments the number 1 equals. So how would the board know which part of the digit to light up.


Make a final decision on your hardware first then the code can come. Exactly how the code works is not a consideration until you decide which type of display you are going to use. Just accept that, no matter what display you choose, as long as you have the necessary hardware to support it, the code can be written.

You just need to make your mind up which hardware to get based on final appearance and cost (and perhaps in your case patriotism :) )

I am not understanding the types of displays. If someone could explain that to me, that would be awesome. I want to use .80" tall 7 segment LEDs. If you need more information about my design just ask. I want to use the TPIC in my project. There will be a total of 8 LED 7 segment displays on each side. I want to use an RF remote because that is easy to wire to the board. I want to use arduino micro because that fits my budget. Now if there is a better place to buy a board that is extremely similar to the micro that is cheaper and is made in the US, I will consider it. I am still not understanding what the TPIC is used for. But, I realize it is needed but I am right now not sure why. In the example when it says wire to a button, the rf remote module is like the button correct? Also if I supply power to the arduino using the USB, I will not need to supply power to the RF remote module correct?
So in the base code I was given, I do not believe that the park of the digits that turn into the number are defined. When the clock hits 0:00 I want a buzzer to ring. I will use an 85dB Piezo Buzzer. You can find these at Radio Shack for $5.
7 Segment display Diagram (One I will Use)

(Some of these might be wrong I was in a hurry)

baucat9: I think I am going to use the pro mini

Do you have a link for that. I don't know what one of those is.

KenF I want to use the micro. I accidentally said pro mini but I meant micro. I may consider arduino uno if there is an advantage to using that over micro. I want to make as confined as possible.

Thanks, Shane

OK but it's really the display you need to consider first. Once you've decided which display you need, then you can work out which arduino you need to drive it.

Personally, I wouldn't go for the mini. It's an expensive option. The way I'd go is to use a more conventional sized arduino for development. Once you have it all working you can then buy just a chip and program it with your finished sketch. The chip will do the same job as the full blown arduino but will be tiny. (and very cheep). This method would not only be cheaper, but would also leave your main arduino free to pursue other projects.

NFD8021Ax is common-cathode, great if you were controlling with MA7219. TPIC6B595 needs to pull individual cathodes low while the anode is connected high. You have the right idea on the fonts. A part like cd74Ac164 with 24mA (high current) outputs can drive the anode of NFD8021Ax. Connect the cathodes to GND.

baucat9: I want to use .80" tall 7 segment LEDs. I will use an 85dB Piezo Buzzer. You can find these at Radio Shack for $5. If you need more information about my design just ask.

At last some concrete requirements! What about power supply? What voltage does that buzzer need?

baucat9: I want to use the TPIC in my project. I am still not understanding what the TPIC is used for.

So can you explain why you want to use it?

baucat9: 7 Segment display Diagram (One I will Use)

Those come in a variety of colours. The various shades of red, amber, yellow and ordinary green would be fine. The "true" green, blue and white colours may or may not present a problem, as they have a higher forward voltage than the other colours.

If you stick to those lower-voltage colours, I think max7219 would make your project easier than the tpic chips, because (1) only 4 chips needed vs. 8 and (2) only 4 resistors needed to set the led current, vs. 256 resistors with the tpic chips.

Thanks Paul I will use the max chip because that makes more sense. Is an uno a good chip for my rough drafts? . I will get the specs on the buzzer and I want to use a standard 5v power supply, butI am not sure how to connect it to the chip. Just to let you know, I was inspired to do this by someone who made a scoreboard for his air hockey table. I will link you to that project if needed. I will order the parts as soon as I have drawn a couple schematics and the design is approved by you guys. Paul I picked out the 7 segment display on purpose. If there is too much power, tell me and I will find one with less. Ken I am still confused on what you mean by picking my display. Please explain further.


Shane, a 5V supply, stabilised or switch-mode, would be much more efficient because the Arduino and the max7219s (and via them, the displays) can run directly from 5V. With 12V you would need to regulate that down to 5V and so inevitably waste more than half the power. Running 32 x 7 seg displays using the Arduino's built in regulator may over stress it.

However a 5V supply may be a problem if your buzzer needs 12V, so see if you can find a 5V buzzer.

Then I will try to use a 5V power supply then. What do you mean 32x7? I thought they were .80" tall.


Is this a good basic arduino board to buy:

Thanks, Shane

baucat9: What do you mean 32x7?

I meant 32 digits with 7 segments each (8 if you use the decimal points), so 256 leds in total. Using max7219, you will have a 1:8 multiplex ratio, so only 32 leds will be lit at once. If they receive 30ma each, that's almost 1A, so too much for the Arduino's on-board 5V regulator to handle, if you attempted to power the whole circuit through the Arduino's barrel connector. With a 1.5~2A 5V power supply, you would bypass the Arduino's on-board regulator and power it through its 5V connector.

baucat9: Is this a good basic arduino board to buy:

Looks fine Shane, but if space is limited, that same supplier offers a Nano 3, which is equivalent but smaller, and easier to prototype with on a breadboard:

So what do I need to modify on my design to comply with the digits?

Thanks, Shane

Not sure what you are asking Shane. We haven't seen a "design" from you yet, like a schematic.

But if you are going to use max7219, you should get the common cathode type of display. (These chips can be made to work with common anode but it is more difficult.) You can choose any of the available colours, I think even the "pure" green, blue or white would be ok, but it might be best to use only those colours or none of them. By that I mean stick to the colours that have similar voltages. You could buy any combination of single, dual or quad digit displays and mix the colours. For example red for the time, yellow for the home team' score and green for the away team.

I am confused on the output an input because on the micro there are only 5 A pins which I assume are input. I am also not sure how to wire the MAX7219. If someone could explain that it would be GREAT!

Thanks, Shane

Shane, the pins marked A are the analog input pins. These are the only pins that can measure variable voltages as opposed to high/low levels. The analog pins can (nearly always) be used as digital inputs or digital outputs. The other pins marked 0 to 13 are digital only but can be either input or output.

Have a look at this page about how to wire up max7219 chips: