Two LEDs one is on the other cannot be on.
- Thread starter Beemakka
- Start date
Thank you. I build two lane drag racing tracks where the cars travel 20 metres in a second or two. I built a timer which needed to operate at 1000th of a second in order to give first and second place. These circuits were complex and took too much time to build.
Then I found a suitable app. It operated off a laptop using the current flowing down the sun.
The stop watch is switched to on by a single microswitch and to off at each lane by two microswtches one for each lane. The stopwatch indicates two numbers say 1.234 and 1.235. This is fine but doesn't indicate which lane was first. The speed is too much for the human eye. Thus an led which lights for the winning lane is required.
Then I found a suitable app. It operated off a laptop using the current flowing down the sun.
The stop watch is switched to on by a single microswitch and to off at each lane by two microswtches one for each lane. The stopwatch indicates two numbers say 1.234 and 1.235. This is fine but doesn't indicate which lane was first. The speed is too much for the human eye. Thus an led which lights for the winning lane is required.
So are you expecting magic??? Anything worth doing takes time.
Use a micro controller. Then you can control anything you want. Any way you want. The Arduino is a bit overkill but very easy to program and very well supported. The hard part is learning to progeam it But again not hard for something this simple.
Are these real cars or model cars?
Here is easy. You just buy it.
https://www.ebay.com/itm/Traxxas-TR...544229&hash=item5200d23197:g:3LQAAOSwE-lZ~S5B
How do you determine each car's time? You must have some hardware. You should be able to derive a "finished" signal from each lane. You would use the first signal to go high (or low, if that works better) to lock out the other signal. Take a look a line drivers that have output enable pins. It seems like there's a pony in there...
An Arduino would be a fine way to go, too. I'll plug the Nano as a cheap solution.
I assume this is a model because 1.2 KPH doesn't sound like real drag racing. At least not very interesting drag racing...
An Arduino would be a fine way to go, too. I'll plug the Nano as a cheap solution.
I assume this is a model because 1.2 KPH doesn't sound like real drag racing. At least not very interesting drag racing...
With a microcontroller you can do all kind of interesting things like log times and report them back to a PC.
The cars are model. 30cm long. I can program picaxe but I thought that was overkill too. Must be a simpler way.
Not really. A microcontroller is going to be a whole lot easier tan a bunch of separate parts.
Anything that is not "overkill" in terms of hardware will take more time to design and etch a PCB, order all the parts...
So, either the labor and effort is overkill or you push the "easy button" d pay too much for the hardware and you can immediately start programming.
You basically need a quiz-show circuit that allows the first contestant to get the light - any additional press by other contestants result in nothing.
A fairly typical textbook example using a 555; the 2 LED are in series, each with its own current limiting resistor. Put that string across the supply rails and both LEDs light dim - connect the 555 output to the point between the 2 LED/resistor combinations and the 555 output will shunt the supply from one to all across the other. The bipolar 555 is good down to 4.5V, but a 3.4V white LED on the output is cutting the margin a bit.
Just a thought. One NAND IC & 2 555's. Assuming switches put out a + signal, a SW signal to one each of NANDs, other NAND input from inverted, other 2 NANDs, opposite 555's. 555's set for maybe 20 sec. driving 2 LEDs. Lane A car hits SW-A putting highs on both inputs of NAND-A, output goes low triggering 555-A, turning on LED-A, inverted output goes to NAND-B, inhibiting NAND-B for 20 sec.
A laptop provides the power via a usb to serial cable to a junction box see http://www.xnotestopwatch.com/ where it is spli three ways one to the start switch and two to each lane at the finish. I would like to add Two LEDs to the junction box which will indicate the winning lane. The first to light up cuts the second from powering up
