So big picture I'm trying to create a shadow / Glow wall for kids to play with. I want the kids to be able to hit a big button (think cartoon big red button) and then 3 seconds count down on a visual timer, and then a flash (like a camera flash, but without the camera) go off to create shadows on the glow in the dark paper.
Camera flashes do have remote controls, but they are small, delicate, and typically have many buttons to control the various functions of the flash. What I'm looking for is more like this:
Which when pressed would wait for a count of 3 seconds and then to fire the flash. I've done some digging and I can't find an off-the-shelf product that would accomplish what I'm looking for. I did find that there are Arduino compatable parts for buttons (https://www.sparkfun.com/products/11275) and timers (https://www.sparkfun.com/products/8530) but I'm not sure if you'd be able to trigger a speedlight or studio camera flash. Would it be possible? and for those with experience how much would it cost to to hire out for help sourcing the parts and guides for assembly? Thanks in advance!
I don't have the photoreciptive (glow-in-the-dark) paper here yet (its on order) so I can't test whether a 75W bulb would generate enough light if flashed. The only instruction I have to work off of is that a camera flash is best, and the bigger the better.
Get the brightest you can and make a 4x4 or bigger. The shadows will have unbra, call it a feature and consider how many photons the short flash will hit the phosphor paper versus 20 to 100ms of these new bright white led bulbs. If the kids can "freeze" for 1 second, you won't need light so bright and of course they will move creatively just to see what it gets.
so your intent is that the "kids" press the button and then have 3 seconds to take the pause they want and then the flash goes ?
a wired button as you listed ( Big Dome Pushbutton) would work
you connect one pin to GND, one pin to a digital pin (say pin D2) or your arduino
the code is pretty straightforward if you make it blocking (ie once pressed you are stuck and the flash will trigger 3s later)
const byte buttonPin = 2; // pin D2 --- button ---- GND
const byte relayPin = 3; // trigger pin of a suitable relay, powered separately
void lampOn() {
digitalWrite(relayPin, HIGH); // or LOW depending on the state that triggers the relay
}
void lampOff() {
digitalWrite(relayPin, LOW); // or HIGH depending on the state that release the relay
}
void setup() {
pinMode(buttonPin, INPUT_PULLUP);
pinMode(relayPin, OUTPUT);
while (digitalRead(buttonPin) == LOW); // wait until button is released if needed
}
void loop() {
if (digitalRead(buttonPin) == LOW) {
// button was pressed
delay(3000); // wait for 3s (3000 ms)
lampOn(); // turn on the flash
delay(100); // for 100ms
lampOff(); // turn off the flash
while (digitalRead(buttonPin) == LOW); // wait until button is released if needed
delay(15); // poor's man anti bounce
} // end if
} // end loop
One question I have is how long does it take for the shadows to disappear? How long does it glow ?
wow, thanks for sharing this! So that seems to take care of the button input, starting the timer, and then issuing a "LampOn". My question, and please forgive my total ignorance, is what types of lamps / lights could I hook up ton arduino system. I really have no experience with arduino so I'm clueless when it comes to the particulars. I just know from a project requirement side that the light is, "very bright" and we'd be ideally looking to hookup something like this (https://www.amazon.com/Impact-SF-ABRL160-Stand-Mount-Modeling/dp/B00EHSS4EA)
The arduino is not a power source. It's just sending a command "ON" or "OFF" to a separate device which will let the high power go through. This is what a relay or a power transistor (/ mosfet) do.
➜ you'll need to know how much current / voltage is required for the lamp to work and if it's an AC or DC source you are driving and you need to find a power module suitable for the power you'll draw.
I was, but I'm 37 and put all my skill points into design. We didn't have cool shit like this when I was growing up (or at least I didn't know about it)
I'm 67 and we had real school budgets before Reagan.
The glow in the dark paper eats photons and releases that energy over a lot more time than the flash. You can feed it way more light with a longer exposure. These bright white bulbs have loads of blue photons in the mix, higher energy can be gotten from UV leds but you do that to kids, you should be jailed so don't go for UV and don't go laser either.
Did you have anything glow in the dark that didn;t get brighter and shine longer when charged with light longer? The new led bulbs are so white they hurt my eyes, the 75W is brighter white than the old 100W (more light but a bit "warmer" and caveat, you need to shop for the starker bulbs than "warm" or "soft" ones. The market sells a range of led houselights.
You can relay house power ON and OFF pretty quickly but do you really want to?
The problem with using house bulbs is that they won't create the "moment in time" capture that a photography flash would accomplish. That effect is what I'm going for.
Looking at the specs of the camera flash I have at work, it looks like it puts out 160 watt seconds which I think equals 160,000 watts.
I'm not saying this wouldn't work, but I don't think it would work. When you plug in a camera flash it doesn't just start firing. They are built to await input from a camera.
It would be my suspision that you would need to "hack" (for lack of a better word) the flash so that the "test fire" button was triggered by your timer.
I had a buddy with a laser pointer, swinging it around to make red lines when the beam hit his fisheye mirror. The dot was moving fast, he only got a short flash and the curved mirror spread the beam out.
He could only see red out of that eye, open or closed for over 90 minutes but his retina got over it.
Any reflective surface can deflect a beam, mirrors on speakers can make audio into spirograph-like lightshows but you need to make sure no eyes get between projector and wall when laser is ON.
With a laser you can project interference patterns but safer by far is using color leds. Try projecting that through smoke or water and starch (cook some pasta) to get a display but don't chance eyes!
Do that to a kid somehow and you will end up in court where stupid jokes get extra punishment.
