/diy/ - Do It Yourself

>>2608687
Well there are different ways to use some of these placeholders, and part of that comes from them including legacy placeholders alongside their current "updated" counterparts.

With the legacy syntax, you use the placeholder name in some [brackets]: M104 S[first_layer_temperature]
With the updated syntax you start with {curly braces}: M104 S{first_layer_temperature[0]}
Now either of those will work, but if you want to use the fun stuff, you need to use the updated syntax with the {curly braces}.

The reason for the [0] in this case is because first_layer_temperature is a vector, it's used to get the temperature of -any- hotend, that [0] is the index of the first hotend.
If you only have one hotend, that's all you need, first_layer_temperature[0], but if you had two hotends you could also use first_layer_temperature[1] to refer to the temp of your second hotend, and so on for additional hotends.

You can find more info from Prusa:
https://help.prusa3d.com/article/macros_1775
https://help.prusa3d.com/article/list-of-placeholders_205643

They really kind of downplay some of the fun shit you can do.
SuperSlicer has more places you can shove custom gcode and more placeholders than PrusaSlicer.
OrcaSlicer and BambuStudio can also do a lot of the same tricks, though between all of these there are some differences in syntax, placeholder names, etc.

In any of these slicers, hover your mouse over a setting to get the tooltip popup, and if that setting corresponds to a placeholder variable that can be used in customer gcode, you'll see something that says "parameter name:"