What do I need to make my LED flash?

[Bjarneec]

Join Date
Jul 2015
Posts
1
Sorry for using this, but Think you Can answer
I need an relay or something that Can do the following:
I am building an race simulator and am building an button box With momentary -normally/open switches as they replaced the keyboard buttons. I wired the button from an old joypad. BUT i really needs an flashing LED to flash when the button is pressed, but as it is a momentary the LED Will just stop flashing when its released again. It need to stop flash when pushing the switch 2. Time. (I need it for speed limiter). What do I need?the joypad is connnected to usb so it must be 5v.

Thanks in advance

[Jazz P Bass]

A 555 timer circuit is what I would use.

Google it.

[bluto]

An Arduino board (or one of the many clones) will do that and MUCH more....or if you want something smaller and less expensive a DigiSpark board might be a good option.
Both can be programmed using the free Arduino IDE software from a PC, Mac, or Linux machine

[Bjarneec]

Thanks for answers

Regarding the digispark, Would this could do it? Is the only thing i need for it the LED, the pushbutton and Then program it in the Arduino software and assign the key or something in the program?
Digispark Kickstarter ATTINY85 USB Development Board for Arduino New | eBay

As im on holiday I dont have much "Google-time"

Thanks for your help

[guitician]

Astable multivibrator. Like the switch used in the Ibanez pedals. Astable Multivibrator (Oscillator)

[northanaya]

chk this LED flashing circuit

[rjb]

Astable multivibrator. Like the switch used in the Ibanez pedals. Astable Multivibrator (Oscillator)

That's the old-school way I'd do it, if I had to.
But why bother, when off-the-shelf flashing LEDs are readily available?
Here's one of many sources:
Flashing | All Electronics Corp.

[J M Fahey]

I need an relay or something that Can do the following:
I am building an race simulator and am building an button box With momentary -normally/open switches as they replaced the keyboard buttons. I wired the button from an old joypad. BUT i really needs an flashing LED to flash when the button is pressed, but as it is a momentary the LED Will just stop flashing when its released again. It need to stop flash when pushing the switch 2. Time. (I need it for speed limiter). What do I need?the joypad is connnected to usb so it must be 5v.

Thanks in advance

Sorry but having a LED flash is only half the problem.

Bjarneec needs to start that Led flashing with one button, then to stop it with another.

Not my cup of tea *at all* but I guess it can all be solved in software.

Now, what's that keyboard connected to, what software is run, that should be known first.

Or if only 2 buttons and a flashing Led are used, and nothing else, then a simple "old style" solution can be imagined, but I *guess* that keyboard is running a much more complex task.

[bluto]

Sorry but having a LED flash is only half the problem.

Bjarneec needs to start that Led flashing with one button, then to stop it with another.

Not my cup of tea *at all* but I guess it can all be solved in software.

Now, what's that keyboard connected to, what software is run, that should be known first.

Or if only 2 buttons and a flashing Led are used, and nothing else, then a simple "old style" solution can be imagined, but I *guess* that keyboard is running a much more complex task.

FWIW that is why I recommended a Arduino or better yet engineering wise a DigiSpark board....I recently used an Arduino to build an overdrive controller for an old British car and also need a toggle function using a single button/momentary contact switch and that was very simple to do, also wired a LED indicator and a current sensor. Total overkill using an Arduino (less so using a DigiSpark, was unaware of it at the time) for this but a fun and educational project and the DigiSpark is cheap. I'd imagine the OP would eventually add more functions, that is my plan with my car too.

[Enzo]

My approach may or may not be compatible here.

I figure the one button starts something, and the other stops it, and the LED is just an indicator. That means whatever it is connected to has some process that either starts and continues or it stops. I would look for something in that system to control my LED. First, I eliminate parallel circuits in the switch box, and second, the LED then becomes a true indicator of status. If the LED is directly controlled by the switch, it only tells us the switch status, not whether or not the system is in any particular state.

Used to be PIC chips, and now we have Arduinos, all of which I am sure are versatile things. But one needs to know how to and be able to program them. Imagine if I made a machine that translated French into English, so I could understand it. I tell my sister, "just say three sentences in French to show it is working." She knows no French. I have been in electronics for 60+ years, and other than the introductory FORTRAN classes I took in 1965, I don't program a lick. When I hear "all you have to do is write a program..." I cringe.

One CMOS or TTL logic IC can be wired as a flip flop that does the exact task the OP requires.

[eschertron]

Join Date
Jul 2015
Posts
1
Sorry for using this, but Think you Can answer
I need an relay or something that Can do the following:
I am building an race simulator and am building an button box With momentary -normally/open switches as they replaced the keyboard buttons. I wired the button from an old joypad. BUT i really needs an flashing LED to flash when the button is pressed, but as it is a momentary the LED Will just stop flashing when its released again. It need to stop flash when pushing the switch 2. Time. (I need it for speed limiter). What do I need?the joypad is connnected to usb so it must be 5v.

Thanks in advance

That's the old-school way I'd do it, if I had to.
But why bother, when off-the-shelf flashing LEDs are readily available?
Here's one of many sources:
Flashing | All Electronics Corp.

Or if only 2 buttons and a flashing Led are used, and nothing else, then a simple "old style" solution can be imagined, but I *guess* that keyboard is running a much more complex task.

I think the keyboard reference is a red herring. The keyboard is being replaced by the box with a button and a LED lamp. A CMOS or TTL flip-flop (in a DIP 6- or 8-pin package?) and one of those flashing LEDs would be easy to put together. First on my list would be to find out if the switches are sinking or sourcing the system inputs.

Flashing | All Electronics Corp. Now that's cool!

[guitician]

The power to the LED needs to latch/un-latch with each press of the button. The OP didn't say what circuit the button closes/opens, or how the LED even gets it's power. The flashing part he already has, as stated. The flip-flop/astable multivibrator type of a circuit will do the job, he just needs to say he's got it working.

[rjb]

To be honest, I don't fully understand the OP's question.
On re-reading, I think he might be doing something like this, with a joypad connected to a PC.
How To Make Your USB Joystick Mimic A Keyboard
And he wants to add a flashing LED, powered by the 5V from the USB connector(?)
And he wants the LED to turn ON when a N.O. switch is pushed, and OFF when it is pushed again?
If so, that sounds like he wants the switch to act like a "Caps Lock" or "Num Lock" key- but with the normal LED replaced by a flashing LED.
So, maybe he can pull the LED display board from an old USB keyboard, like this The Pi & I: Dirty Little Secret About Wireless Keyboards
Then it does become a programming problem- the PC must recognize the switch closure and turn the LED on and off.
Or something like that.

[rjb]

The flashing part he already has, as stated.

I'm not sure about that.
The thread title is "What do I need to make my LED flash?", not "How do I keep my LED flashing?"

[bluto]

My approach may or may not be compatible here.

I figure the one button starts something, and the other stops it, and the LED is just an indicator. That means whatever it is connected to has some process that either starts and continues or it stops. I would look for something in that system to control my LED. First, I eliminate parallel circuits in the switch box, and second, the LED then becomes a true indicator of status. If the LED is directly controlled by the switch, it only tells us the switch status, not whether or not the system is in any particular state.

Used to be PIC chips, and now we have Arduinos, all of which I am sure are versatile things. But one needs to know how to and be able to program them. Imagine if I made a machine that translated French into English, so I could understand it. I tell my sister, "just say three sentences in French to show it is working." She knows no French. I have been in electronics for 60+ years, and other than the introductory FORTRAN classes I took in 1965, I don't program a lick. When I hear "all you have to do is write a program..." I cringe.

One CMOS or TTL logic IC can be wired as a flip flop that does the exact task the OP requires.

I have not been in electronics nearly that long (but long enough to have studied Fortran long ago ;-) ) and had not done any programming in years..but the Arduino platform was developed for education and programming is simple. The IDE has a bunch of examples built in and there are waaay more out the on the web so in many cases (like for my OD controller project) you can find something similar and modify the code to suit. Anyway here is one of the IDE examples for controlling a LED...

/*
Button

Turns on and off a light emitting diode(LED) connected to digital
pin 13, when pressing a pushbutton attached to pin 2.


The circuit:
* LED attached from pin 13 to ground
* pushbutton attached to pin 2 from +5V
* 10K resistor attached to pin 2 from ground

* Note: on most Arduinos there is already an LED on the board
attached to pin 13.


created 2005
by DojoDave <http://www.0j0.org>
modified 30 Aug 2011
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/Button
*/

// constants won't change. They're used here to
// set pin numbers:
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 13; // the number of the LED pin

// variables will change:
int buttonState = 0; // variable for reading the pushbutton status

void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT);
}

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
if (buttonState == HIGH) {
// turn LED on:
digitalWrite(ledPin, HIGH);
}
else {
// turn LED off:
digitalWrite(ledPin, LOW);
}
}