Help Needed: Countdown tone generator.

[SlotRacer]

Hello, my name is Glenn. I know very little about electronics. I can read a schematic and have built several voltage regulators and an IR transmitter/reciever to performing discreet photo triggering for lap timing on my slot car track.

I am using a program called SlotRace Manager. It is a DOS program and it communicates through the parallel port. This software also sends output signals through the PP also. My question is regarding the output.

The output signals goes through a 7 Darlington Array (whatever that is) and illuminates a series of 5 LEDs in a light tree. The LEDs illuminate in order 1 2 3 4, 5. After 5 is lit, the race begins. LEDs 1,2,3 and 4 (red/yellow) then go out and LED 5 (green) remains on for the duration of the race.

I plan on triggering 5V (coil) relays instead of illuminating the LEDs. I want to run brighter and larger bulbs (perhaps 12V).

Now my quandry---> There are no audible signals.

I am looking for 4 or 5 distinct tones (beeps) that will last 1/2-2 seconds upon recieving the initial signal. While signals 1-4 will cease after 4 seconds, signal 5 remains on for the entire race.



I am looking to build a 5 channel tone generator, amplifiable to usable levels. I am also looking for a circuit that will trigger said tone generator upon receiving an initial signal, but will end after a second or two, regardless of any state changes or signal persistance.

I am turning to the experts in this forum. If I knew what I am looking I would simply look it up, but the search results I have obtained indicate I do not know what it is called.

Can anyone help?

Schematic: IC 5 is a 7 Darlington Aray IC. The Relays and the switches control track power.
**broken link removed**
Software sequence of operations:
Tree Light 1 pin val.: red light, 1st to go out
Tree Light 2 pin val.: red light, 2nd to go out
Tree Light 3 pin val.: red light, 3rd to go out
Tree Light 4 pin val.: red light, 4th to go out
Tree Light 5 pin val.: green light, on during race running, Lights 1 thru 4 shut off, 4 seconds after light 5 turns on.

Thanks;
Glenn

 

[ericgibbs]

hi glenn,

One way you could consider would be to use two 555 timers.

One for the 2sec timer and the other as an astable.

The astable could have timing capacitors switched by the outputs of the PP driving the array ic. As each LED line was switched a different capacitor could be slected for the astable, giving a different tone.

As the 555 output is a TTL square wave, it could drive a piezo buzzer directly.

Does this help?

EDIT:
The dwg shows just the outline of the idea.
Download from www.datasheetarchive.com the LM555 datasheet

 

[Souper man]

If you need 2 555, why not use a 556! it has 2 555 built into 1 14pin package. Think that i used too many numbers for 2 sentences...

 

[MrDEB]

What ic is that?

a real easy way to incorporate bigger lights is to use a uln2803 or uln2804
both are darrlington arrays but need external power supply for lights (read 12v lights)
as for tones, a 556 could be wired to produce several tones.
A 558 has 4 timmers in it.
have several circuits in a RS Forrest Mimms book.
will post if need be tomorrow

 

[SlotRacer]

Hmm 556... Let me look ito it I assume I can start looking into an LM556. Also as for the tone generator, I am looking for a sine wave generator. No buzzers please.

 

[MrDEB]

have a diagram for a 3 state tone source using a 556
A 2 tone
steady tone
and a tone burst

 

[SlotRacer]

After a quick trip to my local electronics surplus store, I became convinced that a microcontroller would be the easiest, most predicatable way to do what I want.
There is also this device that will read a USB flash drive and allow the micro controller to play the sound files of my choice. The files can be of any length I chose, thus the duration.

Together I will be able to achieve my desired goal.

Now to build the programming hardware.