Preventing gcode execution under certain conditions

component spindle_interlock """Prevents tool or chuck release when the spindle is running"""; pin in signed encoder-counts "connect this to the spindle encoder"; param rw unsigned encoder-vel = 1 """how many counts per sec to accept as spindle-stopped"""; pin in float spindle-speed-in """Pass-through the spindle speed request only if the release is not activated"""; pin out float spindle-speed-out; pin out bit release-allowed "For operating an indicator lamp, for example"; pin in bit release-request "The release request from the button/pedal"; pin out bit release-out "the release signal to the valve"; pin in bit release-state = 1 """This bit sets the value that is passed to "release-out". Toggle it to 0 or 1 to suit internal or external gripping, for example"""; function _; license "GPL"; author "Andy Pugh"; pin out float vel; pin out unsigned st; pin out float timer; ;; FUNCTION(_){ //static int st = 0; static int last_counts; static double last_timer; //static double timer; //double vel; timer += fperiod; if (last_counts != encoder_counts){ vel = abs(last_counts - encoder_counts) / timer; last_timer = timer; last_counts = encoder_counts; timer = 0; } else { vel = 1/(last_timer + timer); } switch (st){ case 0: // spindle stopped, release allowed if (vel > encoder_vel) { st = 1; break; } if (release_request){ st = 2; break; } release_out = ! release_state; spindle_speed_out = spindle_speed_in; release_allowed = 1; break; case 1: // spindle moving // This state deliberately never changes the release-out pin if (vel <= encoder_vel){ st = 0; break; } spindle_speed_out = spindle_speed_in; release_allowed = 0; break; case 2: // spindle released if (! release_request ) { release_out = ! release_state; st = 0; break; } release_out = release_state; spindle_speed_out = 0; } }