RGBW strip? about homebridge-mqttthing

[arachnetech]

I've added support for RGBW published as red,green,blue,white (each in the range 0-255) in version 1.0.10. Hopefully that will help with Tasmota. It's also now possible to use setOn/getOn in combination with setRGBW/getRGBW (and setRBG/getRGB and setHSV/getHSV). I'm interested to know how you get on, and happy to make further changes (time-permitting) if helpful...

Looking at the Tasmota wiki, I think it may need the white component published as a separate topic OR the RGBW published in hex.

[arachnetech]

Version 1.0.11 can now publish RGBW in hex (use topics.setRGBW and hex or hexPrefix), or as a separate component (use topics.setRGB and topics.setWhite).

[arachnetech]

Great to hear it's mostly working now. Thanks for letting me know. Is it possible to configure the Tasmota firmware to compensate for colour temperature? If not, I could potentially look at adding some kind of gamma correction. What are the LED colours on CWWW strip? Cyan, Warm White, Neutral White and Cold White?

[arachnetech]

mqttthing supports generation of red, green ,blue ,warm_white and cold_white components now (in addition to RGB and RGBW) - but still not just CWWW (unless you process brightness and colour temperature yourself). Adding support for 0-255 levels for warm white and cold white components, calculated from brightness and colour temperature, is next on my list (and should be easier than RGBWW was).

[arachnetech]

mqttthing doesn't currently support extracting RGB or RGBW values from the hue, saturation and brightness exposed by homekit. Currently the options are either to publish these in separate topics, or to combine them a single comma-separate 'HSV' topic (which should really be HSB - I will probably rename this in a future release).

My strips are all RGB currently, and I perform the HSB to RGB conversion in the ESP8266 code. I've experimented (with good results) with RGBW strips by taking min( R, G, B ) away from R, G and B and using this as the W value. While this never achieves full brightness (with all of R, G, B and W on full), it gives much better whites (and near-whites) than an RGB strip.

I'm surprised that there are controllers that accept HSB values (which they presumably convert to RGB internally) but do not have the logic to extract a W component. I'd prefer either to publish unprocessed HSB as I do now (and leave any W channel extraction to happen during conversion to RGB), or to publish RGB or RGBW. Can the tasmota accessories accept RGBW?

[ethan4]

Yes,

The Tasmota wiki says you can set arbitrary decimal values per channel, use hexadecimal values for multiple different configurations including RGBW, or use HSB so I'm guessing hexadecimal RRGGBBWW would do it and then you see the brightness in a separate command.

The Tasmota firmware also has a colour temperature command for strips with two white colours (I presume to emulate the Hue strips with 6 channels).

[ethan4]

Great I’ll test this today and let you know how it goes.

[ethan4]

I've updated to 1.0.11 and tested RGBW with decimal and hex values, both are working well and using all of the channels. I'm getting some strange colors in some places but I think that might be because of the strip I have (warm white and quite high output on the white channel as well).

I think any compensation for the white colour temperature and output should be done by the Tasmota firmware right? EDIT: Created an issue on the Tasmota repo for this.

Any thoughts on doing a mode for a CWWW strip? That would be the same kind of device as a Philips Hue White Ambiance. There are also some 6 channel strips which do RGB,cool white, warm white.

I'll let everyone know on the Tasmota wiki that you've got a good implementation for MQTT+homekit as i'm sure i'm not the only one looking to set things up this way.

[ethan4]

Hi David,

CWWW refers to a two channel light, cool white and warm white in one strip.

[arachnetech]

Feeling stupid now - of course it does! :-)
I will give that some thought...