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67 lines
2.5 KiB
Markdown
67 lines
2.5 KiB
Markdown
node-red-node-pi-neopixel
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=========================
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A <a href="http://nodered.org" target="_new">Node-RED</a> node to drive a strip
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of Neopixel or WS2812 LEDs from a Raspberry Pi.
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Pre-requisites
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--------------
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The Neopixel python driver need to be pre-installed... The easiest way to get
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the driver installed is to use the Unicorn HAT drivers install script... see the
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<a href="http://learn.pimoroni.com/tutorial/unicorn-hat/getting-started-with-unicorn-hat" target="_new">
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Pimoroni Getting Started with Unicorn HAT</a> page.
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curl -sS get.pimoroni.com/unicornhat | bash
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Install
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-------
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Run the following command in the root directory of your Node-RED install.
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Usually this is `~/.node-red`
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npm install node-red-node-pi-neopixel
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The data pin of the pixels should be connected to physical pin 12 - GPIO 18 of the Pi.
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*Note:* this may conflict with audio playback.
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Usage
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-----
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To set the background just set **msg.payload** to an `html_colour` name.
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<a href="http://html-color-codes.info/color-names/" target="_top">Here
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is a list</a> of html_colour names.
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It also accepts a string triple `rrr,ggg,bbb` or `#rrggbb`
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#### Bar Chart
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Defaults style mode using configured foreground and background colours. The foreground colour is used to indicate the number of pixels or length required.
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It accepts a number in **msg.payload** that can be either the number of pixels,
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or a percentage of the total length.
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If you want to change the foreground colour, you can set **msg.payload** to a
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comma separated string of `html_colour,length` or `length,html_colour`. The foreground will then remain that colour until changed again.
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#### Needle
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It can also display a needle (single pixel) type gauge.
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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.
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If you want to change the needle colour, you can set **msg.payload** to a
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comma separated string of `html_colour,length` or `length,html_colour`.
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#### Shift left and Shift right
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You can also select shift modes where a single colour pixel is added to either
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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.
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#### Low level "API"
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The `nth` pixel of the string can be set by **msg.payload** with a CSV string `n,r,g,b` ,
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where r, g and b are 0-255.
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A range of pixels from position `x` to `y` can be set by **msg.payload**
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with a CSV string `x,y,r,g,b`
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