Hello, I am new to this website, so go easy  please.
I  am looking to buy a 500W GRBL controller with a USB port to connect to my laptop. This will replace my old damaged controller. Problem is, there is no spindle stop/start switch or speed control knob.
Can anyone please advise any CAM software that will generate G.Code to do this ?  I  have been using Aspire to generate G.Code, but there is no stop/ start feature in that. 
I  use UGS to run the control box