stepper state engine

src/main.c

@@ -533,59 +533,129 @@ int main() {
       printf("POS: %02d\n", positionSwitch);
     }
 
-    if (timeValidCnt > 0) {
-      if (step != 0) {
+    if ((timeValidCnt > 0) && (step != 0)) {
       step = 0;
 
+      static uint8_t stepperState = 0;
+
       static uint8_t currentMinutePosition = 0;
-        uint8_t minuteStepPosition = clock.minute * STEPS_PER_MINUTE;
+      uint8_t minuteStepPosition = 0;
+      int8_t minuteDirection = 0;
+
+      static uint8_t currentHourPosition = 0;
+      uint8_t hourStepPosition = clock.hour * STEPS_PER_HOUR;
+      int8_t hourDirection = 0;
+
+      switch (stepperState) {
+      case 0:
+        // is current minute position different from desired one?
         if (currentMinutePosition != minuteStepPosition) {
+          printf("M: ");
+
+          stepperState = 1;
+        }
+        break;
+      case 1:
+        // switch on the minute motor and set the direction
         PORTA |= (1 << PA1);
 
-          printf("M: ");
+        minuteStepPosition = clock.minute * STEPS_PER_MINUTE;
+
         if (currentMinutePosition > minuteStepPosition) {
           printf("b ");
-            currentMinutePosition--;
+          minuteDirection = -1;
           PORTC |= (1 << PC2);
         } else {
           printf("f ");
-            currentMinutePosition++;
+          minuteDirection = 1;
           PORTC &= ~(1 << PC2);
         }
-          printf("d: %d, c: %d\n", minuteStepPosition, currentMinutePosition);
+
+        stepperState = 2;
+        break;
+      case 2:
+        // move one step
+
+        printf("d: %d, c: %d, ", minuteStepPosition, currentMinutePosition);
+
+        currentMinutePosition += minuteDirection;
 
         PORTC |= (1 << PC3);
         _delay_us(50);
         PORTC &= ~(1 << PC3);
-        } else {
-          PORTA &= ~(1 << PA1);
-        }
 
-        static uint8_t currentHourPosition = 0;
-        uint8_t hourStepPosition = clock.hour * STEPS_PER_HOUR;
+        if (currentMinutePosition == minuteStepPosition) {
+          stepperState = 3;
+        }
+        break;
+      case 3:
+        // switch off the minute motor
+        PORTA &= ~(1 << PA1);
+
+        stepperState = 4;
+        break;
+      case 4:
+        // is current hour position different from desired one?
         if (currentHourPosition != hourStepPosition) {
+          printf(" H: ");
+
+          stepperState = 5;
+        } else {
+          // done
+          printf("\n");
+          stepperState = 0;
+        }
+        break;
+      case 5:
+        // switch on the hour motor and set the direction
         PORTA |= (1 << PA0);
 
-          printf("H: ");
+        hourStepPosition = clock.hour * STEPS_PER_HOUR;
+
         if (currentHourPosition > hourStepPosition) {
           printf("b ");
-            currentHourPosition--;
+          hourDirection = -1;
           PORTC |= (1 << PC0);
         } else {
           printf("f ");
-            currentHourPosition++;
+          hourDirection = 1;
           PORTC &= ~(1 << PC0);
         }
-          printf("d: %d, c: %d\n", hourStepPosition, currentHourPosition);
+
+        stepperState = 6;
+        break;
+      case 6:
+        // move one step
+
+        printf("d: %d, c: %d, ", hourStepPosition, currentHourPosition);
+
+        currentHourPosition += hourDirection;
 
         PORTC |= (1 << PC1);
         _delay_us(50);
         PORTC &= ~(1 << PC1);
-        } else {
+
+        if (currentHourPosition == hourStepPosition) {
+          stepperState = 7;
+        }
+        break;
+      case 7:
+        // switch off the hour motor
         PORTA &= ~(1 << PA0);
+
+        stepperState = 8;
+        break;
+      case 8:
+        // done
+        printf("\n");
+        stepperState = 0;
+        break;
+      default:
+        stepperState = 0;
+        break;
       }
     }
-    }
+
 
     if (tack != 0) {
       tack = 0;