I'm looking to purchase a large 7-segment display that I can use for an automated sports stopwatch project. The display needs to be large enough that a group of spectators can see the display with ease from 30 or 40 feet away, maybe further. I've had trouble finding one to purchase that also doesn't cost a ton of money.
Next, can anyone link me to a guide on how to use the display with an arduino? I want to display the live time of the stopwatch. For example, athletes will stand on a start pad, the stopwatch will display "0:00:00". When they stop off the pad, the timer will run, and spectators can see the time rolling. When the athlete touches the end pad, the stopwatch will stop and display their time.
Also, I was considering using an LCD screen instead. Would this be as better choice of the 7-segment? What about other types of screens? I've never used a screen on an arduino before, so I don't really know much about any of them.
Hello there,
I guess the first question is how many digits for you plan on making the display? How do you plan on start/ stop/ resetting the stopwatch? Will this be battery powered or run from wall power all the time?
For 30 to 40 feet you can use pretty small digits. Like 3"
I know for a fact 5" digits are easily seen for 150' if you are using the correct LED's
I will need 5 digits. One for minutes, two for seconds, two for hundredths of a second. I plan to use a pressure switch to detect when someone is on the stop/end pads. Then I will write code that recognizes when someone is on the pad and either start or stop the stopwatch accordingly. I hope to make the Arduino battery powered.
I have these 5", 7-segment common anode digits from another project.Each segment runs from 12V and has current limit resistor built in.
You can combine them with this board, which is basically an Arduino populated with up to 12 TPIC6B595 shift registers, to drive them. You would only need 5. Programming is easy, just shift out the 5 digits you want displayed at whatever update rate you want and read whatever switches you need to start & stop time, and a reset button.
The boards are setup with 16-pin ribbon cables on the back, crimp on pins & make up headers to mate with this board.
Programming is via offboard FTDI module.
You don't need sockets, but it helps for repairs when you screw up (seen it happen twice now). http://www.pololu.com/catalog/product/1931
