Add A4988 stepper motor driver

micropython/drivers/a4988/a4988.py

@@ -0,0 +1,53 @@
+import time
+
+# Constants
+STEPS_PER_REV = 200  # Number of steps per motor revolution
+MIN_DELAY = 0.001    # Minimum delay between steps (controls maximum speed)
+
+class A4988:
+    def __init__(self, step_pin, dir_pin, en_pin=None):
+        self.step_pin = step_pin
+        self.dir_pin = dir_pin
+        self.en_pin = en_pin
+        if self.en_pin is not None:
+            self.enable_motor(enabled=True)
+
+    def enable_motor(self, enabled=True):
+        """Enable or disable the motor driver (active low)."""
+        if self.en_pin:
+            self.en_pin.value(0 if enabled else 1)
+
+    def step_motor(self, steps=STEPS_PER_REV, direction=1, delay=0.005):
+        """Move the motor a specified number of steps in the given direction."""
+        self.dir_pin.value(direction)  # Set direction (1 = forward, 0 = backward)
+        for _ in range(steps):
+            self.step_pin.value(1)
+            time.sleep(delay)
+            self.step_pin.value(0)
+            time.sleep(delay)
+
+    def calculate_speed(self, current_delay):
+        """Calculate the current speed in steps per second and RPM."""
+        if current_delay <= 0:
+            return 0, 0
+        steps_per_second = 1 / (2 * current_delay)  # Delay is for each half-step
+        rpm = (steps_per_second / STEPS_PER_REV) * 60  # Convert to RPM
+        return steps_per_second, rpm
+
+    def inc_speed(self, current_delay):
+        """Decrease delay to increase speed, respecting minimum delay limit."""
+        new_delay = max(current_delay - 0.001, MIN_DELAY)
+        return new_delay
+
+    def dec_speed(self, current_delay):
+        """Increase delay to decrease speed."""
+        new_delay = current_delay + 0.001
+        return new_delay
+
+    def forward_motion(self, steps=STEPS_PER_REV, delay=0.005):
+        """Move motor forward for a given number of steps and delay."""
+        self.step_motor(steps=steps, direction=1, delay=delay)
+
+    def backward_motion(self, steps=STEPS_PER_REV, delay=0.005):
+        """Move motor backward for a given number of steps and delay."""
+        self.step_motor(steps=steps, direction=0, delay=delay)

micropython/drivers/a4988/manifest.py

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+metadata(description="MicroPython driver for A4988 stepper motor controller", version="1.0.0")