clean up stepper

firmware/src/constants.h

@@ -32,4 +32,9 @@
 
 #define STEPPER_ENABLE A0
 #define STEPPER_STEP A1
+#define STEPPER_STEP_PORT PORTC
+#define STEPPER_STEP_BIT 1 << 1
 #define STEPPER_DIR A2
+
+#define STEPPER_STEPS_PER_REV 200
+#define STEPPER_MICROSTEPS 2

firmware/src/main.cpp

@@ -15,7 +15,9 @@ void setup() {
   setupDebug();
   setupEncoder();
   setupTimer();
-  setupStepper();
+  if (!setupStepper()) {
+    fatal();
+  }
 
   Wire.begin();
   Wire.setClock(800000);
@@ -30,7 +32,6 @@ void setup() {
 
 void loop() {
   debugScanI2C();
-  demoTimer();
 
   char debugKey = Serial.available() > 0 ? Serial.read() : 0;
 
@@ -59,9 +60,9 @@ void loop() {
     } else if (key == KEY_C) {
       beep();
     } else if (digit == 4) {
-      demo_moveBy(-80000);
+      demo_moveBy(-8000);
     } else if (digit == 5) {
-      demo_moveBy(80000);
+      demo_moveBy(8000);
     } else if (digit == 7) {
       auto micros1 = micros();
       // 0.1ms
@@ -93,7 +94,6 @@ void loop() {
   if (encoderEvent) {
     tick();
     Serial.println(encoderEvent == ENCODER_CLOCKWISE ? "Clockwise" : "Counter-clockwise");
-    // demo_moveBy(encoderEvent == ENCODER_CLOCKWISE ? 800 : -800);
     changeFreq(encoderEvent == ENCODER_CLOCKWISE ? 1 : -1);
     Serial.println(OCR1A);
   }

firmware/src/stepper.cpp

@@ -1,29 +1,43 @@
 #include <Arduino.h>
 #include "constants.h"
+#include "debug.h"
+#include "stepper.h"
 
 /*
 
  A4988 Stepper Motor Driver.
 
- NOTE: minimum pulse width 1us high, 1us low
-
 */
 
-void setupStepper() {
+bool setupStepper() {
   pinMode(STEPPER_ENABLE, OUTPUT);
   pinMode(STEPPER_DIR, OUTPUT);
   pinMode(STEPPER_STEP, OUTPUT);
 
-  // low = enabled
-  digitalWrite(STEPPER_ENABLE, LOW);
+  setStepperEnabled(false);
+
+  // sanity check
+  if (!((int) portOutputRegister(digitalPinToPort(STEPPER_STEP)) == (int) &STEPPER_STEP_PORT
+    && digitalPinToBitMask(STEPPER_STEP) == STEPPER_STEP_BIT
+    )) {
+      Serial.println("Stepper step pin is misconfigured");
+      return false;
+  }
+
+  return true;
 }
 
-void demoStepper(bool dir) {
-  digitalWrite(STEPPER_DIR, dir);
-  for (int i = 0; i < 3200; i++) {
-    digitalWrite(STEPPER_STEP, HIGH);
-    delayMicroseconds(25);
-    digitalWrite(STEPPER_STEP, LOW);
-    delayMicroseconds(25);
-  }
+void setStepperEnabled(bool enabled) {
+  digitalWrite(STEPPER_ENABLE, !enabled);
+}
+
+void setStepperDirection(bool dir) {
+  digitalWrite(STEPPER_DIR, !dir);
+}
+
+inline void step() {
+  // NOTE: minimum pulse width 1us high, 1us low
+  STEPPER_STEP_PORT |= STEPPER_STEP_BIT;
+  delayMicroseconds(1);
+  STEPPER_STEP_PORT &= ~STEPPER_STEP_BIT;
 }

firmware/src/stepper.h

@@ -1,4 +1,9 @@
 #pragma once
 
-void setupStepper();
-void demoStepper(bool dir);
+#define RIGHT 1
+#define LEFT 0
+
+bool setupStepper();
+void setStepperEnabled(bool enabled);
+void setStepperDirection(bool dir);
+inline void step();