Turn on lights button in version 1.4.2
What do the buttons for the heated compartment and open the lights do? can i use it on my reprap 1.4 card?
By default they send firmware g-code if firmware supports it.
You can change the executed code in Printer Configuraion->G-Codes->Button Commands to do what ever you want on click.
For heated chamber we send M141 Sxxx to set temperature. This is not directly adjustable but you can use gcode rpelacements to eecute something different instead if needed.