Go Down

Topic: Controlling mutiple LED modules  (Read 386 times) previous topic - next topic

MediaBuilder

 Hi, Peoples.
I'm new to your forum and have a project I could really use some help with.
I have a 2011 Chevrolet Impala that I'm adding features to turn it into a "Simulated Emergency Vehicle". Basically a Police car. I can then rent it to production companies for use in media productions.
I have most of the lighting figured out and there's several online products I can buy for flashing the head lights, tail lights, reverse lights, etc. Where I'm having problems is with the light bar on top of the car. I just can't afford to buy a 'ready made' light bar. ($800.00 to $1,500.00) I've already figured out how to physically construct the light bar and where and how I'm going to mount all the LED's. I've also figured out how to make and mount a switch box inside the car to turn on and off all the lights and the light bar.
Although I'm really good at designing and building most things, I'm still very ignorant when it comes to electronics.
I'm basing my design on the Federal Signal's "Integrity" model light bar. Although there light bar uses duel color LED's, mine will use single color, 5mm LED's in groups of 10 for each module. With a total of 42 modules. 11 Red, 11 Blue, 12 White and 8 Amber.
I know there are many different Arduino circuit modules and I've watched some videos using the DHT11 and others. I need something that I can attach to 30 of the 42 LED modules and turn them on and off individually for a variety of flash patterns.  The White LED modules will  just be on or off and no flash pattern required.
My question is this: Would you help me gain a better understanding of what I need to hook all the modules to, and how to write the code to make it all work? I want to learn what I'm doing so I can use it in future projects.

Thank you for your help.

Doug

Paul__B

The first thing you need to do, is to specify all your "modules".

What are they?  (Web link?)  How many LEDs, how are they connected?

PaulRB

LEDs of different colours have different forward voltages, and this is important to understand when designing your modules.

Red LEDs have a forward voltage of around 1.8~2V. With a 12~14V supply, you can probably connect 4 or perhaps 5 red LEDs in series to share the same current (around 20mA). So 2 groups per module drawing 40mA each.

Amber LEDs are more like 2.2~2.4V, so you can connect 3 or 4 in series, meaning 3 or 4 groups will be needed per module, drawing up to 80mA per module.

White and blue LEDs are much higher at around 3.2~3.4V, so only 3 in series and 4 groups per module. Again, 80mA per module.

I think the easiest way to control 30 such modules would be to use 4 X tpic6b595 chips. Only 3 Arduino pins would be needed.

Go Up