In this example we have an application which provides an HTTP API for controlling the RGB LED on an SN220.
To run server.py and client.py you'll need a Python environment with SNAPstack and tornado installed.
You'll need SNAPtoolbelt (to load scripts) and SNAPcompiler (to build scripts).
This script is the SNAPstack+Tornado application.
Usage: python server.py path-to-SNAP-bridge-node
e.g. python server.py /dev/snap1
This script uses the Tornado HTTPClient to talk to the server's API.
Usage: python client.py
This is the SNAPpy script to load on your SN220.
To build node.spy: spyc node.py
To load node.spy on your bridge node: toolbelt node bridge script load node.spy
On and off for the RGB LED elements are encoded as the low 3 bits of a single int: 0b0rgb.
0b0100 (4) is "red on", 0b0010 (2) is "green on", 0b0001 (1) is "blue on". These values are bitwire OR'd together to get the combined value.
get_rgb() -> rgb:
set_rgb(rgb):
This API represents RGB LED state as a JSON object: {"r":1,"g":0,"b":1}
The snap_address can be a 6-character SNAP MAC address or bridge, to use the bridge node.
GET /(snap_address)/rgb: Request state of RGB LEDs
POST /(snap_address)bridge/rgb: Set RGB LEDs to the given LED state