7 Segment Displays

Discussion in 'The Projects Forum' started by Jx3069, Dec 4, 2012.

1. Jx3069 Thread Starter New Member

Dec 4, 2012
2
0
Hi everyone, I'm new to this forum and was refer here by a friend from school whom told me people here are extremely friendly and helpful. I'm trying to do a final project for my digital class on the display counter similar to this video http://www.youtube.com/watch?v=4PcL6-mjRNk.
What I'm trying to do is have 2 7 segment display linked together and attached to a mechanical switch, which adds 1 to the counter on the 7 segment every time the switch is closed to represent how many times the ball has shot out. Also I want to have a toggle switch that's able to change the display to a 2nd internal count which would represent average distance traveled say 3m every time that switch is depressed, my question is would be it be easier to have 4 total 7 segment display 1 for count of "ball shot" and the other for count "distance travel" or is it possible to have a toggle switch that enables me to use the same two 7 segment display and switch between displays?
Any tips or hints would be greatly appreciate!! Thank you!

2. tshuck Well-Known Member

Oct 18, 2012
3,527
679
there isn't much more work in using 4 SSDs(seven segment display) versus two. You can, of course, use two SSDs and toggle to answer your question, but as personal preference, I don't like having to toggle between different display modes, so I'd go with a display for each variable you are concerned with...

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3. elec_mech Senior Member

Nov 12, 2008
1,513
195
You could do this using the following:
• Four BCD Up/Down counter ICs
• Two BCD to 7-segment display ICs
• Two 7-segment displays
• One DPDT switch to toggle between the two data sets
The counter ICs are put into pairs so that one counts balls and the other counts distance, each from 00 to 99. Each pair will have eight outputs - two BCD values for each digit: A, B, C, D for ones and tens place.

The A for the ones place of the balls counted goes into one of two multiplexer inputs, the A for the ones place of the distance travelled goes into the second multiplexer input. Using HEF4519 as an example, there are two inputs, SA and SB, that determine which of the two inputs is on the output. SA and SB must be at different logic levels (one is low, one is high) for the correct switching to take place. The DPDT switch will take care of this as long as it is wired properly.

The output of the multiplexer is then fed to the input of the display IC then to the display itself.

Alternately,
• Four BCD Up/Down counter ICs
• Four BCD to 7-segment display ICs as long as they have a blanking pin
• Several small signal diodes
• Two 7-segment displays
• One SPDT switch to toggle between the two data sets
Diodes go on the output pins of the display ICs to the displays. Use a SPDT switch to blank one of the display ICs at a time.

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4. Jx3069 Thread Starter New Member

Dec 4, 2012
2
0
Awesome, thanks for the suggestions, I'll give it a shot and see how it goes!