Basically, could I use a PWM digital output on an Arduino on a buckpuck wired for dimming instead of a potentiometer?
I don't think so but I'm not an expert for this kind of device.
But why not using a digital potentiometer?
Do they make them on a breakout board that would be easy to wire to the Arduino +5V digital pins?
You could low-pass filter the PWM and use that, but unless the puck says it accepts PWM, I'd say no.
Do they make them on a breakout board that would be easy to wire to the Arduino +5V digital pins?
Not that I am aware of. But it's in a 8-pin DIP housing so it's pretty easy to solder it on a prototyping pcb or shield and make the connections yourself.
I've got a couple of the buck pucks and have been planning to try running PWM through a big capacitor to smooth it out and give it a try, but haven't gotten around to it yet.
So I emailed LED Supply, and asked if they had any LED drivers with integrated digital potentiometers. Here is their incredibly fast response:
"Hi Chris,
The D-E model BuckPuck can be used with a 0-5V dimming signal (BuckPuck DC LED Drivers). The 1000mA BuckBlock LED driver is compatible with a 0-10V dimming signal (BuckBlock DC LED Driver). The webpages linked above provide links to the respective data sheets with diagrams for dimming. Feel free to contact us again if you have more questions."
It appears that the 0-10 dimming signal would be from a PWM pin... I've emailed back and asked for clarification.
Thanks all for going so easy on a noob.
Yup... from a press release:
"In many applications, it can be used with no additional heat sinking. Fully protected against reverse polarity, output short circuit and output open circuit, the A009 is also fully dimmable (0 – 10V) with both analog and PWM compatibility. "
For a 0-10 V signal you would need to use an op-amp or similar since the logic signal is 5v... I use a variation of this circuit for a similar light dimming application on my aquarium.
http://ruggedcircuits.com/html/circuit__20.html
So the logic signal from ALL the Arduino PWM pins is only 5 volts?? Hmm. Didn't know that. If that's the case, is there a pre made op amp I could buy and wire to the 5 volt PWM pin?
You could also use just an npn transitor with two properly selected resistors for an inverted control
Ahhhh, here we go: BuckPuck DC LED Drivers
But the Arduino PWM pins are for sure all digital?
But the Arduino PWM pins are for sure all digital?
Yes.
Sorry, brain fart, still drinking my morning coffee, of course they are all digital, I mean to type are they all 5 volt?
If that's what the supply voltage is, yes, near enough.
Unless they're really badly loaded.
Thanks! LOVE the O Brother quote in the sig, by the way!