I am working on a project which will have 3 different sets of LED strips (5v) each with it's own code controlling what, how and when it does what it does.
Obviously the Arduino won't power it, I'm looking at up to 3 amps, so it seems the standard approach is to use MOSFETS.
However, it would appear one needs one MOSFET per colour channel, per strip, so that's 9 in total. A fetish of MOSFETS? (not sure what the collective noun is, however that sounds right).
However the Arduino doesn't have 9 PWM channels out.
And it also seems a bit overkill to have to create a board with 9 MOSFETs on it.
Am I completely missing some other obvious way to do this? I have searched, however most information is on controlling and powering one strip only.
Obviously the Arduino won't power it, I'm looking at up to 3 amps, so it seems the standard approach is to use MOSFETS.
If you want PW/dimming, yes. You need MOSFETs or transistors. MOSFETs tend to run cooler and generally handle more current. For on/off control you could use relays.
And yes, for 9 channels you'll need 9 of them.
If you make MOSFET drivers, build & test 1 of them before you build 9.
However the Arduino doesn't have 9 PWM channels out.
The Arduino MEGA has 15 PWM outputs. Or, you can search for "Arduino PWM expander".
An alternative might be [u]NeoPixels[/u] which are individually-addressable RGB LEDs with a built-in driver. (You don't need MOSFETs and you can address an almost unlimited number of LEDs.)
PaulS:
Three sets of strips? How many strips in a set?
They are those USB TV back light sets, that tend to come in 4 x 50cm, which I like because they have bendy connectors and run off 5v. I might be using between 1-4 in series for any of the 3 "sets". Currently it's 2/2/4
wildbill:
Do you have a link to the strips you're using?
DVDdoug:
If you want PW/dimming, yes. You need MOSFETs or transistors. MOSFETs tend to run cooler and generally handle more current. For on/off control you could use relays.
And yes, for 9 channels you'll need 9 of them.
If you make MOSFET drivers, build & test 1 of them before you build 9.
The Arduino MEGA has 15 PWM outputs. Or, you can search for "Arduino PWM expander".
An alternative might be [u]NeoPixels[/u] which are individually-addressable RGB LEDs with a built-in driver. (You don't need MOSFETs and you can address an almost unlimited number of LEDs.)
If I don't use PW dimming (ie changing the colours to anything other than bright white), I assume the LEDs will not live as long?
What do you mean by "drivers"? You mean to drive the current I assume, not a driver in the code.
I looked at the Mega, however that seemed quite large, I need something about the size of the mini.
I think I'll got the expanders, as I already got the LED strips, however looks like NeoPixel type thing would have been the best way to go. Seems that about 95% of my circuit will be MOSFETs.
