I've been lurking in these forums for awhile now, I'm an engineering student (biomedical) and picked up an arduino a few months back as a hobby/learning experience.
I've built several small project, pretty simple things using LEDs, photoresistors, pots etc... The usual starting point.
Today I came up with a project idea today for my basement that I'm remodeling.
The problem is, I don't know how to approach it or if it's even possible to do (cheaply).
I'd like to build some LED's into the bar area and them controlled by photoresistors.
The problem is...there are 31 locations that I'd like to place them. Each with their own photo resistor.
I have understand the basics of using an LED matrix and charlie plexing/shift registers.
My initial thoughts were to wire them up into a 6x8 matrix (17 of the locations wouldn't have LED's)
Right now I'm only working with my UNO and don't have a whole lot of trouble understanding the LED's but get lost when trying to figure out a way to add the photoresistors as controls. (Ideally, I would love to use RGB led's..which only complicates things further...but thats not a must.)
Is it even possible? What direction should I head if it is?
How big is this bar your're building? Are you using a single led on each of the 31 locations?
How are you going to build the sensor/led assembly? Using a light sensor next to a light source to control said light source seems like a bad idea to me due to feedback.
To control the leds i would recommend a MAX7219 or 7221 Arduino Playground - MAX72XXHardware
Or a TLC5940 Arduino Playground - TLC5940
As for the photoresistors i would assume you need to make something with a common wire
Say you wire 31 photoresistors into one input and control how each an everyone of them get power
What i would research is if you can use a SIPO register to turn on and of the photoresistors
Say you use 4 analog inputs and wire 8 to each input. And then using 4 8-channel registers to check one resistor at the time. (would be 4 at the time since you use 4 inputs)
Does this make sense?
Anyone feel free to shoot this down. im taking a guess here.
OUEGB:
I'd like to build some LED's into the bar area and them controlled by photoresistors.
The problem is...there are 31 locations that I'd like to place them. Each with their own photo resistor.
Well, what is it that you want each LED to do with respect to the R of the photoresistor (LDR)? Get brighter/dimmer in response to ambient light? Is each LDR going to be co-located with the LED it's associated with?
Without knowing how you want your LEDs to behave, there's little point in guessing about how or whether to connect them to an Arduino. After all, a simple circuit with a battery and a transistor and I suppose a couple more parts could be used to dim an LED or even turn it off. Heck, just a WAG here, but depending on current draw and the LDR characteristics, maybe even wire an LED in series with it?