This block helps to set roller position in relation to sun position.
Download this json file:
Go to Node-red.
Press ctrl + i or ⌘-i in your workplace or in top right corner press settings (three horizontal lines) and Import.
From now on there should be this block in subflows.
Drag this block to your flow and double click it. Enter your data here (latitude, longitude etc.).
For block to work properly you also need to download and install Node named node-red-contrib-sun-position.
Now you can just use inject block.
Just drag first block and plug in.
and click on blue button.
Roller should point at sun.
If you want roller to point at sun for example every 15 minutes then double click on blue block and set repeat to interval and set interval to 15 minutes. If you also want for algorithm to start working after server restart, pick Inject once after.
If you want to change variable percentage of the sun (how much of sun light enters the room), you can just edit field in the Sun tracking block and enter value from 0 to 100.