error display with -E-

src/display.rs

@@ -83,17 +83,19 @@ impl SegmentPins {
 
 #[derive(Clone, Copy, PartialEq, Eq)]
 pub enum SegmentState {
+    Off,
     Num(u8, bool),
     Minus,
     Prompt(bool),
     Dot,
-    Off,
+    E,
 }
 
 impl SegmentState {
     pub fn apply(&self, seg: &mut SegmentPins) {
         seg.set_off();
         match self {
+            SegmentState::Off => (),
             SegmentState::Num(no, dp) => {
                 match no {
                     0 => {
@@ -179,7 +181,13 @@ impl SegmentState {
                     seg.set_dp()
                 }
             }
-            SegmentState::Off => (),
+            SegmentState::E => {
+                seg.set_a();
+                seg.set_d();
+                seg.set_e();
+                seg.set_f();
+                seg.set_g();
+            }
         }
     }
 }
@@ -251,15 +259,15 @@ impl DispalyState {
 
     pub fn error(&mut self) {
         self.set([
+            SegmentState::Off,
+            SegmentState::Off,
+            SegmentState::Off,
             SegmentState::Minus,
+            SegmentState::E,
             SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
-            SegmentState::Minus,
+            SegmentState::Off,
+            SegmentState::Off,
+            SegmentState::Off,
         ])
     }
 }