One of my high school seniors has chosen to design a simple, inexpensive, portable scoreboard for displaying the score at a volleyball game. The mechanical part is coming along nicely, but I'm a little light on the electronics end, as I am new at using pics. I do however teach intro to digital electronics.

We would like to design a circuit that does the following:

• Displays the score for Home and Away on two separate scoreboards (so both teams can see).
• Each score board will have 2 2 digit 7seg displays so the score can go up to 99 to 99. Below is a crude image of what we think the setup will look like:

• Has two buttons for home, and two for away: 1 button increments the team's score by 1, one button decrements the team's score by one. (2 buttons each team, 1 up and 1 down) The score goes up or down by one each time the correct button is pressed.
  
• Has a master reset button that zeros the displays.
  
• It should be inexpensive, and easy to produce the circuit, and program.

I think the easiest way to do it is with a PIC, but maybe not. I am a hardware guy, not a software guy, and I will be learning PICS myself with this project. I am looking for ideas from the ground up. Should we use a PIC? What type? What other logic is needed? etc.....

Thanks in advance for any help!

I think using a PIC would result in the least amount of components but depending on how familiar you are with PICs and programming for them, it may not be the easiest for you. This would be a good project to learn PICs with in my opinion. You could debounce the pushbuttons with software, increment or decrement a variable based on button pushes, reset the variable to zero based on another button push, etc. You would need to have some kind of sub routine that converted the value of the variable into 7 seg output. If you decide to pursue the PIC option, there are people here who could help you.

However, there are ICs that already exist that are specifically designed to do what you need. This IC:

CD4510BE Texas Instruments Counter Shift Registers

will count up, down, or reset based on button presses. It also has the built in functionality for you to cascade it for use with multiple digits.

You could use the first IC in conjunction with this one:

CD4543BE Texas Instruments Encoders, Decoders, Multiplexers & Demultiplexers

This second IC will decode the BCD output of the first IC into a 7 segment signal that you could use to drive the display.

You could connect the outputs of the second IC to transistors to drive the individual segments. It probably wouldn't be a good idea to drive the segments of the 7 segment digit directly from the IC but I haven't thoroughly gone through the data sheet to make sure.

You would need 4 of the first IC and 4 of the second IC but at roughly $.50 each, I think that would still fall into the cheap category.

this might help??
Laurier's Handy Dandy Little Circuits:One digit counter
its a shuffle board score board.

Thanks for the good start vne147 and MrDEB! We looked at both data sheets and the website, and they head us in the right direction. I think we are going to go with the pic, as most of what we want to do can be done with simple programming, just not by me at the moment.

Do you know of someone who would be a good candidate as an adviser that wold like to help out my student and myself with the pic programming aspect of this circuit?

Thanks again!

Originally Posted by churd

Do you know of someone who would be a good candidate as an adviser that wold like to help out my student and myself with the pic programming aspect of this circuit?

A lot of people on this board including myself are willing and able to help. There are tons of PIC tutorials out there you can use to get started. Just do a google search for it. I would personally recommend using C over assembly. It's a higher level language and in my opinion requires less of a learning curve. Assembly is good to know but not necessary for this project. One of the standard first PIC projects out there to help someone learn has you write a program to blink an LED on and off. That should get you started and then later on you can use what you learned to turn the number segment on and off. Post any questions you might have or problems you encounter and people here can help you. Good luck.

Thanks! Just downloaded a boatload of tutorials, and we'll get to work after Thanksgiving!