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Topic: motion of a candle flame for a project (Read 2569 times) previous topic - next topic

Derrane

Hi everyone,

I have just started with arduino so i dont know alot.Im a trying to create a connection with objects for a project. I'm trying to detect the movement of a candle flame and sync a light bulb with it so the light bulb flickers. i would be very grateful if someone could advise me on a good sensor and the way to go about creating this connection between the two objects.

Thanks!

AWOL

Please do NOT cross post the same question in different sections; it wastes time when people answer it in both parts.
I have deleted your other post.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

robtillaart

Hi Derrane,

The easiest way to get started is with 4 LDR's looking at the candle at different angles - LDR =  Light dependant resistors. You connect these to the analog in of the Arduino to 4 analog ports. See - http://learning.codasign.com/index.php?title=Light_Dependent_Resistors_and_Arduino -

Instead of printing the values you can put the values in a function that approximates the flickering. The output of that function is send with digitalWrite to a PWM port control a LED light. You can find this on the reference pages and tutorial sections of arduino.cc

You can also map every LDR onto its own LED, program a memory effect and add additional random fluctuations but that is for version 2.0. First get started with 0.1 understanding teh sensors and the basic program.
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

Derrane

Thanks, instead of a LED, i would like it to be a household lightbulb but i know the voltage output would not light an average household bulb and i would need another power source and i have researched arduino boards and i am thinking arduino uno would be best for me especially as i am just starting off but  i want to be 100% sure.

Derrane

also is it possible to run 4 LDR's from an arduino uno to the one light bulb???

robtillaart

yes
an Arduino UNO has 6 analog ports so you can even do 6.

YOu can combine these values into one value between 0-255 and use this to analogWRite() a PWM signal which is used to drive teh lightbulb.
But the latter you should ask on the electronic subforum: - how to drive a 220V bulb with PWM.

[mind you I don't know the formula of combining the 4/6 inputs to one output. Averaging does not seem like a good idea, as you want both the peaks and teh minima and duration and ...
If you find the formula please post  :)

Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

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