ld_drive: make settings private & add set & get fn

src/laser_diode/ld_drive.rs

@@ -45,8 +45,8 @@ impl Settings{
 
 #[derive(Clone, Debug, Miniconf)]
 pub struct Settings {
-    pub ld_drive_current: ElectricCurrent,
-    pub pd_i_to_out_pwr: i_to_power_unit,
+    ld_drive_current: ElectricCurrent,
+    pd_i_to_out_pwr: i_to_power_unit,
 }
 
 impl Default for Settings {
@@ -85,6 +85,14 @@ impl LD_Drive{
         self.ctrl.power_down();
     }
 
+    pub fn get_ld_drive_current(&mut self) -> ElectricCurrent{
+        self.settings.ld_drive_current
+    }
+
+    pub fn set_pd_i_to_out_pwr(&mut self, val: i_to_power_unit){
+        self.settings.pd_i_to_out_pwr = val;
+    }
+
     pub fn ld_short(&mut self) {
         self.ctrl.ld_short_enable();
     }