Continuous servos and DC motors work.

Author: tannewt

adafruit_motor/motor.py

@@ -30,12 +30,12 @@
 Shield for Arduino v2 Kit - v2.3 <https://www.adafruit.com/product/1438>`_ do this for popular form
 factors already.
 
+.. note:: The TB6612 boards feature three inputs XIN1, XIN2 and PWMX. Since we PWM the INs directly
+  its expected that the PWM pin is consistently high.
 
 * Author(s): Scott Shawcroft
 """
 
-import math
-
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_motor.git"
 
@@ -63,9 +63,9 @@ def throttle(self):
         if self._positive.duty_cycle > 0 and self._negative.duty_cycle > 0:
             raise RuntimeError("PWMs in invalid state")
         value = max(self._positive.duty_cycle, self._negative.duty_cycle) / 0xffff
-        if self._negative > 0:
+        if self._negative.duty_cycle > 0:
             return -1 * value
-        return values
+        return value
 
     @throttle.setter
     def throttle(self, value):
@@ -78,7 +78,7 @@ def throttle(self, value):
             self._positive.duty_cycle = 0xffff
             self._negative.duty_cycle = 0xffff
         else:
-            duty_cycle = 0xffff * math.abs(value)
+            duty_cycle = int(0xffff * abs(value))
             if value < 0:
                 self._positive.duty_cycle = 0
                 self._negative.duty_cycle = duty_cycle

adafruit_motor/servo.py

@@ -49,8 +49,6 @@ def __init__(self, pwm_out, *, min_pulse=1000, max_pulse=2000):
         self._duty_range = int(max_duty - self._min_duty)
         print(self._min_duty, self._duty_range)
         self._pwm_out = pwm_out
-        self._min_pulse = min_pulse
-        self._pulse_range = max_pulse - min_pulse
 
     @property
     def _fraction(self):
@@ -60,7 +58,6 @@ def _fraction(self):
     def _fraction(self, value):
         """The fraction of pulse high."""
         duty_cycle = self._min_duty + int(value * self._duty_range)
-        print(self._min_pulse + int(value * self._pulse_range))
         self._pwm_out.duty_cycle = duty_cycle
 
 class Servo(_BaseServo):

examples/continuous_servo.py

@@ -3,21 +3,27 @@
 from board import *
 import busio
 
-# Import the PCA9685 module.
+# Import the PCA9685 module. Available in the bundle and here:
+#   https://github.com/adafruit/Adafruit_CircuitPython_PCA9685
 from adafruit_pca9685 import PCA9685
 
-# This example also relies on the Adafruit motor library available here:
-# https://github.com/adafruit/Adafruit_CircuitPython_Motor
 from adafruit_motor import servo
 
 i2c = busio.I2C(SCL, SDA)
 
 # Create a simple PCA9685 class instance.
 pca = PCA9685(i2c)
+# You can optionally provide a finer tuned reference clock speed to improve the accuracy of the
+# timing pulses. This calibration will be specific to each board and its environment. See the
+# calibration.py example in the PCA9685 driver.
+# pca = PCA9685(i2c, reference_clock_speed=25630710)
 pca.frequency = 50
 
 # The pulse range is 1000 - 2000 by default.
-servo7 = servo.ContinuousServo(pca.channels[7], min_pulse=600, max_pulse=2500)
+servo7 = servo.ContinuousServo(pca.channels[7])
+# If your servo doesn't stop once the script is finished you may need to tune the
+# reference_clock_speed above or the min_pulse and max_pulse timings below.
+# servo7 = servo.ContinuousServo(pca.channels[7], min_pulse=1000, max_pulse=2000)
 
 print("Forwards")
 servo7.throttle = 1

examples/dc_motor.py

@@ -0,0 +1,62 @@
+# This example uses an Adafruit Stepper and DC Motor FeatherWing to run a DC Motor.
+#   https://www.adafruit.com/product/2927
+
+import time
+
+from board import *
+import busio
+
+# Import the PCA9685 module. Available in the bundle and here:
+#   https://github.com/adafruit/Adafruit_CircuitPython_PCA9685
+from adafruit_pca9685 import PCA9685
+
+from adafruit_motor import motor
+
+i2c = busio.I2C(SCL, SDA)
+
+# Create a simple PCA9685 class instance for the Motor FeatherWing's default address.
+pca = PCA9685(i2c, address=0x60)
+pca.frequency = 100
+
+# Motor 1 is channels 9 and 10 with 8 held high.
+# Motor 2 is channels 11 and 12 with 13 held high.
+# Motor 3 is channels 3 and 4 with 2 held high.
+# Motor 4 is channels 5 and 6 with 7 held high.
+
+# DC Motors generate electrical noise when running that can reset the microcontroller in extreme
+# cases. A capacitor can be used to help prevent this. The demo uses motor 4 because it worked ok
+# in testing without a capacitor.
+# See here for more info: https://learn.adafruit.com/adafruit-motor-shield-v2-for-arduino/faq#faq-13
+pca.channels[7].duty_cycle = 0xffff
+motor4 = motor.DCMotor(pca.channels[5], pca.channels[6])
+
+print("Forwards slow")
+motor4.throttle = 0.5
+print("throttle:", motor4.throttle)
+time.sleep(1)
+
+print("Forwards")
+motor4.throttle = 1
+print("throttle:", motor4.throttle)
+time.sleep(1)
+
+print("Backwards")
+motor4.throttle = -1
+print("throttle:", motor4.throttle)
+time.sleep(1)
+
+print("Backwards slow")
+motor4.throttle = -0.5
+print("throttle:", motor4.throttle)
+time.sleep(1)
+
+print("Stop")
+motor4.throttle = 0
+print("throttle:", motor4.throttle)
+time.sleep(1)
+
+print("Spin freely")
+motor4.throttle = None
+print("throttle:", motor4.throttle)
+
+pca.deinit()

examples/servo_sweep.py

@@ -3,34 +3,42 @@
 from board import *
 import busio
 
-# Import the PCA9685 module.
+# Import the PCA9685 module. Available in the bundle and here:
+#   https://github.com/adafruit/Adafruit_CircuitPython_PCA9685
 from adafruit_pca9685 import PCA9685
 from adafruit_motor import servo
 
 i2c = busio.I2C(SCL, SDA)
 
 # Create a simple PCA9685 class instance.
 pca = PCA9685(i2c)
+# You can optionally provide a finer tuned reference clock speed to improve the accuracy of the
+# timing pulses. This calibration will be specific to each board and its environment. See the
+# calibration.py example in the PCA9685 driver.
+# pca = PCA9685(i2c, reference_clock_speed=25630710)
 pca.frequency = 50
 
 # To get the full range of the servo you will likely need to adjust the min_pulse and max_pulse to
 # match the stall points of the servo.
 # This is an example for the Sub-micro servo: https://www.adafruit.com/product/2201
-# servo7 = servo.Servo(pca.channels[7], min_pulse=580, max_pulse=2480)
+# servo7 = servo.Servo(pca.channels[7], min_pulse=580, max_pulse=2350)
 # This is an example for the Micro Servo - High Powered, High Torque Metal Gear:
 #   https://www.adafruit.com/product/2307
-# servo7 = servo.Servo(pca.channels[7], min_pulse=600, max_pulse=2400)
+# servo7 = servo.Servo(pca.channels[7], min_pulse=500, max_pulse=2600)
 # This is an example for the Standard servo - TowerPro SG-5010 - 5010:
 #   https://www.adafruit.com/product/155
-# servo7 = servo.Servo(pca.channels[7], min_pulse=600, max_pulse=2500)
+# servo7 = servo.Servo(pca.channels[7], min_pulse=400, max_pulse=2400)
 # This is an example for the Analog Feedback Servo: https://www.adafruit.com/product/1404
-# servo7 = servo.Servo(pca.channels[7], min_pulse=600, max_pulse=2600)
+# servo7 = servo.Servo(pca.channels[7], min_pulse=600, max_pulse=2500)
 
 # The pulse range is 1000 - 2000 by default.
 servo7 = servo.Servo(pca.channels[7])
 
+# We sleep in the loops to give the servo time to move into position.
 for i in range(180):
     servo7.angle = i
+    time.sleep(0.03)
 for i in range(180):
     servo7.angle = 180 - i
+    time.sleep(0.03)
 pca.deinit()