(If you are still reading this)
I got it working, but am now having problems understanding the modes.
Defaults style mode using configured foreground and background colours. The foreground colour is used to indicate the number of pixels or length required.
It accepts a number in msg.payload that can be either the number of pixels, or a percentage of the total length.
If you want to change the foreground colour, you can set msg.payload to a comma separated string of html_colour,length or length,html_colour. The foreground will then remain that colour until changed again.
It can also display a needle (single pixel) type gauge. The rest of the pixels are set to the background colour on one side, and the foreground colour on the other side of the indicated pixel.
If you want to change the needle colour, you can set msg.payload to a comma separated string of html_colour,length or length,html_colour.
Shift left and Shift right
You can also select shift modes where a single colour pixel is added to either the start or the end of the strip, shifting all the others along by one. In this mode the msg.payload can be specified as either an html colour name, an r,g,b triple or #rrggbb.
What is the difference between
bar chart and
How do I
shift left (or right)
I can't resolve the syntax to understand what I need to send to do these.