4 Channel I2C AC Dimmer Light Bulb Smart Home for Arduino and Raspberry 110V 220V 50hz/60hz for IOT Projects

This works as a dimmer, but not how you might expect.First things first: I am in the USA, where voltage is 120 V and frequency is 60 Hz. I have not tested this at 230 V/50 Hz.Now, the set-point you program is not a brightness level (e.g. 0 = dark, 100 = bright, like most "smart" devices I've worked with), but it is a "dimness" level (i.e. the higher the number the lower the output). That's stated in the docs I found, so I can't take any points away for that peculiarity.However, the reason I feel justified in giving only three stars is that despite the fact that you can set each channel to 100-0, they are not all valid values! In fact, the dimming range is much narrower than you might think, given the 100-0 range. I had to do a little work to get it to behave like other power controllers.I found that values from 0 to about 18 do, for all intents and purposes, produce a full power output (> 95%). Values between 30 and 48 are pretty linear (72%-30% output). Values between 66 and about 78 result in a 100% output. Anything from there to 100 produce 0% output.What I ended up doing to "straighten this out" is to map each set-point to the true-RMS voltage at the terminals of a connected 40-watt incandescent bulb. I plotted the results and decided that, in my opinion, this device has only about 30 or so truly distinct output levels, not the 100 you might think. I decided to create a mapping array that would create 32 set-points (a power of 2), where 0 is off and 31 is full on. That's roughly 3% power output per step. Here's my map (in Python list syntax):map = [66, 65, 61, 59, 57, 55, 53, 51,50, 48, 47, 46, 44, 43, 42, 41,39, 38, 37, 35, 34, 33, 32, 30,28, 27, 25, 23, 21, 18, 14, 0]So if I want a power level of 50% (31 * 50%, or about 15), I get the 15th element in my map array, which is 41, and write that to the dimmer. At that setting, **MY** dimmer produces a voltage output of about 84 volts, which, in terms of percent power is (84 volts/120 volts)^2 = about 49% power output.The board looks like it is of very high quality construction, and the blue LEDs that indicate voltage and line frequency are a nice touch. On **MY** unit the triac heat sinks appear (according to **MY** voltmeter) to be isolated from the "hot" line conductor, but there are lots of other points on this board that are live, so be careful.I would buy it again, but I would be more interested in working with the developer to see if there is a way to rewrite the firmware to get the full dimming range. If he or she will provide new firmware or the source code to this device's microcontroller, I'd be happy to upgrade this review to 5 stars.

Supposed to control brightness over 0 to 100 command range. However, dufus has set 0 level as full on instead of full off. Another fail, there is no documentation for this condition. Around 68 (just past midway) it fails to work properly, it is almost full off--measured wattage is nearly zero . At 71% (just somewhat past midway) it suddenly turns full, also failing to operate properly. So the 0 to 100 control range does not work. Seller refuses to answer any questions or verify the proper range of operation. GO SOMEWHERE ELSE FOR YOUR NEEDS.

works great.

it worked very well with my arduino