Author Topic: tennis count (Read 3640 times)

icoms8 · « **on:** October 15, 2008, 11:10:42 PM »

i am trying to build a tennis score keeping robot. And i only have a $30-$50 buget. I found a body for 4.07$ but i need to know where to find a cheap way to display the score. i am also useing the $50 robot MC but not the program. Can i have some help on how to tell the display how to show 40-30 or 3-4 or some other tennis score. Thks

airman00 · « **Reply #1 on:** October 16, 2008, 01:20:02 AM »

what do you mean by tennis score keeping robot? It sounds like a regular scoreboard to me

Just use large 7 character LED displays

ArcMan · « **Reply #2 on:** October 16, 2008, 12:18:10 PM »

This may be just what you're looking for:

http://www.surpluscenter.com/item.asp?UID=2008101613120536&item=11-3223&catname=electric

icoms8 · « **Reply #3 on:** October 16, 2008, 05:27:19 PM »

i know it is just a repular score board but i thougt it would be fun to make. And i kind of whated to use a LCD display with 5 or more digits because it is small.

airman00 · « **Reply #4 on:** October 16, 2008, 05:30:59 PM »

Just get 5 and control them all from one microcontroller.

Just like this :

bens · « **Reply #5 on:** October 16, 2008, 06:26:13 PM »

I know this isn't very helpful, but I just need to say that it's very hard for me to not read the subject of this thread as "tennis court".

HDL_CinC_Dragon · « **Reply #6 on:** October 16, 2008, 06:35:57 PM »

"tennis count" actually

icoms8, your best bet IMO would be to just get four 7 segment LED displays (2 for each teams score) and just use an MCU to turn on or off each segment using the same principle as the $50 robot uses for its LED indicator light. You would need an MCU with only about 30 controllable pins to be able to control each individual segment of each display. Then you could store the on-off combinations for each number(0-9). So lets say they scored 1 point. Now they have '1'. In the MCU it would say "hey, whats the combination(could be hex, binary, or decimal) for '1' on displayOne? Ok cool, run that combination!" and then presto! you have a '1' being displayed on displayOne. displayTwo through displayFour would be running the '0' combination.

See what I mean?

-EDIT-
Another possibility that might cost you more and isnt really that efficient is to have 5 MCUs for the whole thing. The first will be the entire brains keeping track of the scores and all that jazz. The other four would be specifically to control the segments so they would only need like 7 or 8 data pins. I think the trickiest part of that would be just getting the four slave MCUs to talk to the one master MCU which really isnt that hard I dont think.

Hope this helps!

-Dragon

icoms8 · « **Reply #7 on:** October 17, 2008, 11:07:42 PM »

ok i have a few more questions. Will this one work http://www.allspectrum.com/store/product_info.php?products_id=56 and were do the pins go . and would would i need for it to run?

icoms8 · « **Reply #8 on:** October 17, 2008, 11:11:04 PM »

Oh and what is a cheap power source i can use

HDL_CinC_Dragon · « **Reply #9 on:** October 18, 2008, 12:10:08 PM »

No, the display itself is .25 inches. No one will be able to read it from more than like 10 feet

-EDIT-
as for power from plugging into a wall, find some old adapter that outputs around 6 volts from a wall jack. Get yourself a nice 5v regulator to give the MCU a nice steady supply of food(voltage) and have the 7segs run off the raw. I wouldnt use more voltage than 7 volts off the adapter because thats 2 volts your VReg is going to be converting to heat which is bad. That would be very hot. You would need a switching regulator(VERY efficient) to regulate the 5v.

If youre using a battery, get a 6v 2000mAh(2Ah) NiMH battery pack with a vreg for the MCU and use the raw 6v to drive the 7segs. be sure to use current limiting resistors! With that power source, you should be able to run that thing for like a week before recharging lol

-EDIT-
From that same website, I would get this instead:
http://www.allspectrum.com/store/product_info.php?cPath=23&products_id=163&osCsid=031633c77fe57b9cd77acd9fd5d05618&sdesc=2.3%22+7+Segment+LED%2C+Common+anode%2C+Super-Red+Model+%23+SA23-11SRWA

icoms8 · « **Reply #10 on:** October 18, 2008, 01:47:27 PM »

ok what kind of resitor should i use and i was thinking of useing a battry holder and some nimh rechargeable batterys. also how should the MC be set up. and i found one led display that is .50 and they will be holding it so it does not matter how small it is.

Trumpkin · « **Reply #11 on:** October 18, 2008, 02:42:42 PM »

Use this to find what resistor value you need R=(supply voltage - voltage led is rated for)/I

Quote

how should the MC be set up.

Connect the positive sides of the LEDs in the display to the digital ports of the microcontroller.

icoms8 · « **Reply #12 on:** October 18, 2008, 03:27:17 PM »

ok what IC sould i use and also how many pins should i add to the MC?

Trumpkin · « **Reply #13 on:** October 18, 2008, 05:56:44 PM »

An atmega 8 or 168 would do or maybe an attiny2313? What do you mean by "how many pins should i add to the MC"

airman00 · « **Reply #14 on:** October 18, 2008, 05:58:43 PM »

get a BCD to 7-segment Display and control it from your microcontroller . This reduces the number of pins needed from 7 ( 7 LEDs ) to 4 pins ( parallel binary control).

So you have five 7 segment displays . Each display requires 4 of your microcontroller pins . Therefore you need 20 output pins of a microcontroller ( 5 displays * 4 pins). Look for an AVR chip with 20 output pins ( or use a demultiplexer[which is controlled by the MC] that outputs the number of outputs you need)

Also, something you might look into is if there is a special dedicated IC that converts serial data or analog signal to 7 segment LED.

more info: http://www.thelearningpit.com/lp/doc/7seg/7seg.html

icoms8 · « **Reply #15 on:** October 18, 2008, 07:24:45 PM »

how do you attach the display to MC. can you crip it?

airman00 · « **Reply #16 on:** October 18, 2008, 07:30:40 PM »

Quote from: icoms8 on October 18, 2008, 07:24:45 PM

how do you attach the display to MC. can you crip it?

Quote from: airman00 on October 18, 2008, 05:58:43 PM

more info: http://www.thelearningpit.com/lp/doc/7seg/7seg.html

whats crip?

icoms8 · « **Reply #17 on:** October 18, 2008, 07:47:46 PM »

sorry i ment crimp, and can i use regluar AA batterys for it and how many do i need?

airman00 · « **Reply #18 on:** October 18, 2008, 10:24:40 PM »

Quote from: icoms8 on October 18, 2008, 07:47:46 PM

sorry i ment crimp, and can i use regluar AA batterys for it and how many do i need?

solder on wires to the BCD and crimp on connectors.
If you use a standard voltage regulator you would need anything over 7V ( each AA battery has 1.5V) LM7805 is an example of a standard 5V regulator
If you use a low-dropout regulator you would need anything over and including 6V. (so 4 AA batteries) LM2940 is an example of an LDO 5V regulator

icoms8 · « **Reply #19 on:** October 19, 2008, 06:56:31 PM »

what is the BCD? and where do i soder the resitors?

Trumpkin · « **Reply #20 on:** October 19, 2008, 07:07:26 PM »

Quote

where do i soder the resitors?

To the LEDs in the display.

airman00 · « **Reply #21 on:** October 19, 2008, 07:14:29 PM »

Quote from: icoms8 on October 19, 2008, 06:56:31 PM

what is the BCD?

I meant solder on wires to the BCD to LED chip - the thingy that controls the 7 segment LED with less pins than direct control of the 7 segment LED

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Author Topic: tennis count (Read 3640 times)

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