I’m experimenting with ColorDMD Sigma Color Changing and getting some unexpected results. I have 5V connected to “+” on the ColorDMD’s Lamp-In connector and, using an Arduino, I send a PWM signal (a value from 0 to 255) to the G, R, and B pins. If I set a value of 255 on all three pins, I see the display’s normal color (I have my ColorDMD set to “50”, a nice bright purple). When I send a value other than 255 to G, R, and B, I get a dim color. For example, if I set the values to 0,0,0, I don't get bright white (I get a not-so-bright cyan). I’ve tried many different values for G, R, and B. Instead of seeing a wide range of colors, I just see a handful of dim colors.

So my question is this. What PWM values do I need to send to the Lamp-In connector if I want to see nice bright colors on the ColorDMD? Like a bright yellow, or white, bright green, etc. Or is it even possible?

Good call Dmod . I hooked R to a different Arduino pin and got it working. There's something I'm still unclear about. Let's say I set G, R, and B to 255 (a steady 5V "high"). The display defaults to the color set in the menus as expected. If I lower the PWM duty cycle on "B", the display turns blue as expected. All good. However, if I slowly lower the duty cycle on "B", from 100% to 0%, the blue doesn't vary in intensity or hue. "G" and "R" behave the same way. Is that the way it's supposed to work? In other words, for me, the ColorDMD controller sees "high" or "low" on each Lamp-In pin and doesn't care about the in-between PWM values. I think that means only 8 colors are possible using the Lamp-In connector.

As I understand it, the PWM signal coming out of my Arduino Uno is either 490 Hz or 980 Hz (depending on the pin). I don't have an oscilliscope, but I've been assuming that 0 (which is 0% duty cycle) is equivalent to steady low.

OK. There are certain "bright" colors available via the ColorDMD menu buttons that I would like to reproduce using the Lamp-In connector. For example, 20 is a nice, vivid green. 30 is a bright cyan, and 50 is a bright purple. Is it possible to reproduce those colors via the Lamp-In connector? So far, I haven't been able to reproduce them and I'm getting the impression that it's not possible (due to automatic level control and/or gamma correction). Why do I want bright colors? Well, besides the fact that they look good, I was thinking that at certain points in the game, when things are chaotic, I could detect that and make the ColorDMD change from its default color to something like bright red. So far, the best I've been able to achieve by mixing PWM signals is a dim red.

OK, thanks. I'll play around with it some more. By the way, congrats on your first SPIKE release, Game of Thrones. Looks amazing!

Just an update. Using an Arduino's PWM outputs, I can definitely produce different colors on my ColorDMD by changing relative contributions of G, R, and B. Right now, the thing I can't figure out is how to mimic some of the colors I can get via the ColorDMD menu buttons. A good example is the value "50" in the ColorDMD menu. It's a great color, vivid, bright purple. I haven't found any combination of Lamp-In signals that can produce that color. I'm wondering if certain colors are impossible. Or could it be that I just haven't found the recipe yet? If anyone figures it out, please let me know