push button LED light with modes

B

blakesphere

Guest
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips? I don't have programming gear. If I can build it
with timer ICs or logic ICs, that would be great!

Thanks, in advance.
Blake
 
blakesphere wrote:
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips? I don't have programming gear. If I can build it
with timer ICs or logic ICs, that would be great!

Thanks, in advance.
Blake
Clock a '1" into a shift register, use the first output to
Click to expand...
switch the led, the second together with a 555 chip to pulse
the led, and connect the 3rd output to the reset of the shift register.
 
On Sun, 22 Feb 2009, blakesphere wrote:

Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips? I don't have programming gear. If I can build it
with timer ICs or logic ICs, that would be great!

Go to the store, and buy any of a number of bicycle lights. They all
Click to expand...
seem to have the ability to go between always on and flashing. You
can get tiny ones that run off button cells (which are great pocket
flashlights but have a tendency to go on too easily when something in
your pocket touches the button) to full blown headlights.

The first LED flashlight I bought was a bicycle headlight, about 5 years
ago. I was curious, and at ten dollars it was cheaper than LED
flashlights of equivalent power. Worked fine, but gave it away to
someone with an actual bike.

The trouble was that as a source of light, you rarely need flashing.
It can become a bother to have to cycle through the modes to turn it
off. Better to ask how to modify one to avoid the flashing mode.

When I bought that first LED bicycle light, people were still going
on in this newsgroup about making LED flashlights. By now, there's
really no good reason to make one, you can surely get one cheaper
than buying the parts. You will have to buy the white LEDs, unless
you buy a cheap LED flashlight to take the LEDs out of. And once
you are buying in order to get cheap LEDs, there's little reason
to build. At the very most, buy a commercial LED bike light, and
put it in the package of your own making.

Michael
 
On Sun, 22 Feb 2009 15:56:43 -0800, blakesphere wrote:

I'd like to use a momentary push button, perhaps a small tactile switch.

The circuit would light the LED. Another press would cause it to flash.
And a final press of the switch would shut off the light.
Click to expand...
See the appended LTSpice model for a general idea (note that most part
numbers and values were pulled out of thin air).

Can something like this be done simply without getting into programmable
chips? I don't have programming gear. If I can build it with timer ICs or
logic ICs, that would be great!
Click to expand...
Anything that can be built with a microcontroller can also be built
out of discrete logic. But the microcontroller approach will almost
invariably be simpler.

Version 4
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TEXT 1168 512 Left 0 ;555
 
On Sun, 22 Feb 2009 19:16:34 -0800 (PST), blakesphere
<blakesphere@gmail.com> wrote:

On Feb 22, 7:58 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll
wrote:
Clock a '1" into a shift register, use the first output to
switch the led, the second together with a 555 chip to pulse
the led, and connect the 3rd output to the reset of the shift register.

OK. I'll look into shift registers. Thanks.

I guess I could do more states if I wanted to. With a wider register?

Say:

1 = steady on
2 = very fast flash
3 = medium flash
4 = slow flash
5 = off

cheers,
Blake
Click to expand...
Do you know how to proceed towards a realistic design? (Do you
understand that he was recommending using the push button as a clock
input and that you may want to use a schmitt trigger gate input or
some other arrangement to debounce it? Etc.)

Jon
 
On Sun, 22 Feb 2009 19:21:57 -0800 (PST), blakesphere
<blakesphere@gmail.com> wrote:

On Feb 22, 9:42 pm, Nobody <nob...@nowhere.com> wrote:
Anything that can be built with a microcontroller can also be built
out of discrete logic. But the microcontroller approach will almost
invariably be simpler.

I'm sure.

But I'll need to buy more gear, get some software (I gather there's
free public domain or GPL stuff), and learn how to program is these
environments... So that's weeks or months down the road. If that's
what I have to do, well, I guess I'll have to start learning
microcontrollers. But I'm still learning discrete stuff.

I can sorta make sense of this stuff you sent. But I guess I'll need a
particular application for the full visual effect...

Thanks though.
Blake
Click to expand...
It's probably worth the learning curve, long term. You can almost
always get access to an assembler directly from the manufacturers (or
from someone they affiliate closely with) without charge. The c
compilers may require a gcc-based implementation for a free version,
which may be a bit "batty" to use at times or quite good, depending.
You should carefully look for debugging support before buying, as you
may need this in order to move along quickly in your learning. And
things may be a bit "spotty" there if you are using GNU GCC, depending
on the processor.

For hobby use, the Microchip PIC parts are good because Microchip has
an active forum board and there are plenty of designs around. Many of
their processors are like the "transparent man" in that you get to see
pretty much how a CPU is designed, when using one (people complain
about just how "bad" their machine language is... but it remains a
very good way to learn about cpu operation, all the same.) Atmel has
some very nice parts, though I can't say that the company does well by
hobbyists in terms of active support, direct from them. They like
"big buyers." But their parts are nice and there are some very nice
development tools available, so they are fine to work with even
without a lot of hand-holding from Atmel. Texas Instruments has some
very nice parts with the MSP430 line and some very cheap entry-level
hardware, as well.

All of these have various peripherals. And learning how to "think"
well about them will take some serious effort. You can ignore all
that and just concentrate on learning about I/O pins and directly
working them in software and still get a lot done without having to
learn about various peripherals and how to make those work.

However, you are right. It's a learning experience. But once you get
past some of the initial barriers (mental road blocks), you will
rapidly find them useful for a whole range of ideas. It's an
investment of time that will pay itself off entirely after just two or
three projects.

Jon
 
On Sun, 22 Feb 2009 19:21:57 -0800, blakesphere wrote:

I can sorta make sense of this stuff you sent. But I guess I'll need a
particular application for the full visual effect...
Click to expand...
LTSpice:

http://www.linear.com/designtools/software/ltspice.jsp

Save the text with a .asc extension, open in LTSpice, click the "run"
button to perform the simulation, then click on traces or components to
view voltage/current waveforms.
 
On Feb 22, 7:58 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll>
wrote:
Clock a '1" into a shift register, use the first output to
switch the led, the second together with a 555 chip to pulse
the led, and connect the 3rd output to the reset of the shift register.
Click to expand...
OK. I'll look into shift registers. Thanks.

I guess I could do more states if I wanted to. With a wider register?

Say:

1 = steady on
2 = very fast flash
3 = medium flash
4 = slow flash
5 = off

cheers,
Blake
 
On Feb 22, 8:43 pm, Michael Black <et...@ncf.ca> wrote:
Go to the store, and buy any of a number of bicycle lights.  They all
seem to have the ability to go between always on and flashing.  You
can get tiny ones that run off button cells (which are great pocket
flashlights but have a tendency to go on too easily when something in
your pocket touches the button) to full blown headlights.
Click to expand...
Hey, thanks for the suggestion.

I did take apart one of the white LED bicycle headlights. But the COB
is covered so I have no idea how it works. It's back on the bike
now...

cheers,
Blake
 
On Feb 22, 9:42 pm, Nobody <nob...@nowhere.com> wrote:
Anything that can be built with a microcontroller can also be built
out of discrete logic. But the microcontroller approach will almost
invariably be simpler.
Click to expand...
I'm sure.

But I'll need to buy more gear, get some software (I gather there's
free public domain or GPL stuff), and learn how to program is these
environments... So that's weeks or months down the road. If that's
what I have to do, well, I guess I'll have to start learning
microcontrollers. But I'm still learning discrete stuff.

I can sorta make sense of this stuff you sent. But I guess I'll need a
particular application for the full visual effect...

Thanks though.
Blake
 
"blakesphere" <blakesphere@gmail.com> wrote in message
news:9a8aaf1e-2714-4ffd-a671-
OK. I'll look into shift registers. Thanks.
I guess I could do more states if I wanted to. With a wider register?
Say:
1 = steady on
2 = very fast flash
3 = medium flash
4 = slow flash
5 = off
Click to expand...
You could have the switch (debounced) clocking a binary counter (say
74HC393), with the counter output connected to the select lines of a MUX
(say 74HC151), with the last count output tied to reset the whole thing.
This would cycle through your modes, allowing you to feed whatever "mode
signal" you like into each channel of the MUX. e.g. first MUX input LOW (LED
off), second MUX input HIGH (LED ON), 3rd MUX input say 5Hz clock (fast
flash), 4th MUX input say 2Hz clock (medium) flash, etc

Dave.
 
blakesphere wrote:
On Feb 22, 7:58 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll
wrote:
Clock a '1" into a shift register, use the first output to
switch the led, the second together with a 555 chip to pulse
the led, and connect the 3rd output to the reset of the shift register.

OK. I'll look into shift registers. Thanks.

I guess I could do more states if I wanted to. With a wider register?

Say:

1 = steady on
2 = very fast flash
3 = medium flash
4 = slow flash
5 = off

cheers,
Blake
Yep. just use the first unused output to reset the shiftregister.
Click to expand...
Common length 4 or 8 stages.
 
blakesphere wrote:
On Feb 22, 7:58 pm, Sjouke Burry <burrynulnulf...@ppllaanneett.nnll
wrote:

Clock a '1" into a shift register, use the first output to
switch the led, the second together with a 555 chip to pulse
the led, and connect the 3rd output to the reset of the shift register.


OK. I'll look into shift registers. Thanks.

I guess I could do more states if I wanted to. With a wider register?

Say:

1 = steady on
2 = very fast flash
3 = medium flash
4 = slow flash
5 = off

cheers,
Blake
Click to expand...
Like the man said. Debounce a switch, use the debounced
output to clock a 4017. A 4017 will give you up to 10
outputs. Use each output to activate whatever function
you want. Tie 5 to the reset.

See: http://www.doctronics.co.uk/4017.htm

It explains the 4017 pretty well, and includes a LED
chaser circuit. But, since you'll use a debounced switch
instead of the 4093 oscillator to clock the 4017, it will
increment only when you press the switch. (You could use
a 4093 in the debounce circuit if you want.)

Ed
 
On Feb 22, 6:56 pm, blakesphere <blakesph...@gmail.com> wrote:
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips? I don't have programming gear. If I can build it
with timer ICs or logic ICs, that would be great!

Thanks, in advance.
Blake
Click to expand...
Is the pursuit the learning experience or the end result at lower
cost? There are plenty of multi-mode LED drivers at http://www.dealextreme..com
or http://www.kaidomain.com. Worst comes to worst, order one (they're
only about $4 ea.) and learn from the circuit before DIY.
 
On Feb 22, 11:35 pm, emailaddr...@insightbb.com wrote:
Is the pursuit the learning experience or the end result at lower
cost?  There are plenty of multi-mode LED drivers athttp://www.dealextreme.com
orhttp://www.kaidomain.com.  Worst comes to worst, order one (they're
only about $4 ea.) and learn from the circuit before DIY.
Click to expand...
Well. That's a really, really good question. :)

I am proactively teaching myself electronics. Learning basic digital
circuits now... Going slow. But I'm enjoying it.

Still, I get ideas. Things I want to do! I start wondering how things
work. I think of projects I want to build. This one? Maybe I'm getting
a bit ahead of myself. So, to learn it properly, I've got other things
to do first.

I appreciate your suggestion though. I can always buy something
prefab, if in a hurry.

cheers,
Blake
 
On 2009-02-22, blakesphere <blakesphere@gmail.com> wrote:
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips?
Click to expand...
someone's making those chips they use in bike lights,
if you could get one of them it'd be fairly simple.
 
On Tue, 24 Feb 2009, Jasen Betts wrote:

On 2009-02-22, blakesphere <blakesphere@gmail.com> wrote:
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips?

someone's making those chips they use in bike lights,
if you could get one of them it'd be fairly simple.

Of course, the most available source, and maybe the cheapest, is
Click to expand...
in those very lights, complete with the needed LEDs. Then one has
to consider what the end goal is.

Michael
 
On 2009-02-22, blakesphere <blakesphere@gmail.com> wrote:
Hi,

I'd like to build a LED circuit. I have a very basic knowledge of
electronics, components, etc.

I'd like to use a momentary push button, perhaps a small tactile
switch.

The circuit would light the LED. Another press would cause it to
flash. And a final press of the switch would shut off the light.

I've looked around for a circuit like this but I can't seem to find
anything! I can find all kinds of flip-flops and oscillators and
astable multi-vibrators. But again that's just one of the "modes" I
would like to have.

Can something like this be done simply without getting into
programmable chips?
Click to expand...
It can be done with simple logic chips. There is a circuit out there
for "debouncing" a pushbutton switch. Have that clock a 4017 or similar
counter-divider, whose #3 output is connected to its reset pin. The 4017
will cycle through states "0", "1", and "2".

Have the "1" pin ANDed or NANDed with a squarewave oscillator. Put the
output of that and the output of the 4017's "0" pin through diodes to a
MOSFET gate that has a 100K resistor to ground. The MOSFET switches the
LED.

I think there is a switch debounce circuit using a schmidt trigger
inverter such as the 40106. The 40106 has 6 inverters in it - one of them
can be used for the squarewave oscillator.

If you want to get more modes with this, you can. With the 40106, some
of the inverters can be used to make oscillators at different frequencies.
You may be able to use 5 of them. The 4017 has outputs "0" through "9" -
ten of them. You can use up to 7 of them - on, off, and five blinking at
different rates. One can have a blink rate fast enough to appear
continuously on at half power.

The schmidt trigger squarewave oscillator can be modified by having the
feedback resistor replaced by two in parallel, except one of those two
resistors would have a diode in series with it. That will change the dury
cycle of the squarewave. With a flash rate too fast to see, different
duty cycles will give different brightnesses.

- Don Klipstein (don@misty.com)
 
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