Dawn Simulator?

Hello all,

I recently picked up an Arduino Uno, and had a great time soldering everything together and getting it all programmed. Good times.

But now, it's time for me to make things happen - winter is coming, and I hate waking up in the dark.

I could do with some pointers for getting this ball rolling. I've already got an RTC, and I just need something else to hook it into. I've got a full-spectrum tester floodlight for me to play with at the start, but I really have no idea how to connect it to the Arduino, or program it.

I've done the Ladyada tutorials, so I should be ready to follow some basic instructions or concepts if someone can lay them down or point me towards them.

tldr: How should I connect my lamp to the Arduino so that I can control it's brightness?

I've got a full-spectrum tester floodlight for me to play with

That's nice for you. What is it?

redlazer: tldr: How should I connect my lamp to the Arduino so that I can control it's brightness?

Electrical spec for the lamp?

Hi, Yes we need more details on the lamp. Is it dimmable?

Maybe start with the ArduinoInfo.Info WIKI page about controlling power and lamps: http://arduino-info.wikispaces.com/ArduinoPower

If you want to really simulate dawn, look at Wikipedia for terms like "Astronomical Twilight", "Civil Twilight" etc. You need to understand the light levels and the curve of the rate at which they change. Maybe there is also information about spectral changes.

I believe you can use a good digital camera somehow to get accurate Light Level readings. Google for that.

Aha! Thanks for the link, now I'm starting to get it.

Hopefully I can now answer your question - please stick with me as I'm not familiar with this stuff, but am learning quickly.

I have a standard desk lamp with an on/off switch, with a 100W light bulb in it, floodlight-style. It's a standard incandescent bulb as far as I'm aware - there's no ballast or anything like that.

I assume because it's a standard bulb, it's dimmable. Having just read about PWM, it's AC, so that means I cannot use PWM, correct?

Thanks again!

Hmmm. So the question is: "What's the easiest/low cost AC Main Dimmer that's easy to drive from Arduino..

I'm thinking, but Anyone Else??

is this one useful? http://www.instructables.com/id/Arduino-controlled-light-dimmer-The-circuit/ http://www.instructables.com/id/Arduino-controlled-light-dimmer-The-circuit/

is this one useful?

This one can be useful, but it’s unavailable…

Anyone seen a similar product?? This is not a complex device…

I may try to source one… Just need more Time In The Day… Also Night.

I need more time too!

In looking online, it looks like I just need a relay to control a light - correct?

But what about dimming?

How do people go about dimming lights these days, anyways?

Why can't I use PWM? Do I have to switch to LED's (or DC?) to use PWM?

Thanks again for your help guys - I'd be more active but I'm super busy these days! I should have more time after the election, though.

This seems like a good solution:


Has anyone used one of these before?

Thanks again!

I've done one of these and love it to pieces. What I did for the light is to drive a white LED strip by connecting the positive power wire between the supplied LED power supply (it's a constant current driver) and the LED strips through one of these: MOSFET Power Control Kithttps://www.sparkfun.com/products/10256 It works great for lower voltage LED's but won't work for full 110VAC.

I too used an RTC chip to know what time it is and then coded a lookup table to know when local sunrise is at my home. Mine turns on at 5:30am every day and turns off around 15 minutes after local sunrise. You could also use a light sensor to trigger turning it off. I had mine fade up and then fade down.