2nd commit

calibrate.py

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+# Example Python Servo Script #2 – Calibrating Range
+# The first script makes use of the Gpiozero defaults. It assumes the servo uses a signal frame width of 20ms.
+# The pulse width for the minimum and maximum rotation is assumed to be 1ms and 2ms. This information should be
+# available in the servo specification and I would avoid sellers that don’t provide this data.
+# I found that with the default settings my servo only moved +45/-45 degrees. I changed the pulse width parameters
+# in order to get a full 90 degrees of rotation in either direction .
+
+
+from gpiozero import Servo
+from time import sleep
+
+myGPIO = 17
+
+myCorrection = 0.45
+maxPW = (2.0 + myCorrection) / 1000
+minPW = (1.0 - myCorrection) / 1000
+
+servo = Servo(myGPIO, min_pulse_width=minPW, max_pulse_width=maxPW)
+
+while True:
+    servo.mid()
+    print("mid")
+    sleep(0.5)
+    servo.min()
+    print("min")
+    sleep(1)
+    servo.mid()
+    print("mid")
+    sleep(0.5)
+    servo.max()
+    print("max")
+    sleep(1)
+
+# The servo should now move between its minimum, middle and maximum positions with a small delay in-between.
+#
+# In this example the min pulse width is decreased from the default of 1 by a correction of 0.45 to 0.55ms.
+# The max pulse width is increased from the default of 2 by 0.45 to 2.45ms. This gave my servo a full 90 degrees
+# of rotation in both directions. The values “0.55” and “2.45” are divided by 1000 to convert them to milliseconds.
+#
+# There is nothing magical about “0.45”. It was just the correction that worked best for my servo.
+#
+# To work out these numbers I started with :
+#
+# myCorrection=0
+# maxPW=(2.0+myCorrection)/1000
+# minPW=(1.0-myCorrection)/1000
+#
+# and increased/decreased the correction number in increments of 0.05. This allowed me to find the biggest change
+# I could make before the servo sounded unhappy.
+#
+# “myCorrection” has to be a number between 0 and 1 but is unlikely to ever need to be 1!

min-max-demo.py

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+# Example Python Servo Script #1
+# Once connected the easiest way to get your servo moving is to use the Gpiozero library in a Python script.
+
+
+
+from gpiozero import Servo
+from time import sleep
+
+myGPIO = 17
+
+servo = Servo(myGPIO)
+
+while True:
+    servo.mid()
+    print("mid")
+    sleep(0.5)
+    servo.min()
+    print("min")
+    sleep(1)
+    servo.mid()
+    print("mid")
+    sleep(0.5)
+    servo.max()
+    print("max")
+    sleep(1)

precision_positioning.py

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+# Once you’ve determined the min and max pulse width values you can use the “value” feature to position the servo arm
+# anywhere between its limits.
+# Setting the “value” parameter to a number between -1 and +1 moves the arm between its minimum and maximum positions.
+# Examples include :
+#
+# Minimum position
+# servo.value=-1
+#
+# Mid-point
+# servo.value=0
+#
+# Maximum position
+# servo.value=1
+#
+# Position between mid-point and maximum
+# servo.value=0.5
+
+#The script below generates a range of “value” numbers to sweep the servo between its maximum and minimum position
+
+from gpiozero import Servo
+from time import sleep
+
+myGPIO = 17
+
+myCorrection = 0
+maxPW = (2.0 + myCorrection) / 1000
+minPW = (1.0 - myCorrection) / 1000
+
+servo = Servo(myGPIO, min_pulse_width=minPW, max_pulse_width=maxPW)
+
+while True:
+
+    print("Set value range -1.0 to +1.0")
+    for value in range(0, 21):
+        value2 = (float(value) - 10) / 10
+        servo.value = value2
+        print(value2)
+        sleep(0.5)
+
+    print("Set value range +1.0 to -1.0")
+    for value in range(20, -1, -1):
+        value2 = (float(value) - 10) / 10
+        servo.value = value2
+        print(value2)
+        sleep(0.5)
+
+# The servo should now move between its minimum, middle and maximum positions with a small delay in-between.
+#
+# The first “For” loop generates a set of integers between 0 and 20. The value has 10 subtracted from it to give a
+# range -10 to 10. The value is then finally divided by 10 to give a range of -1 to +1. The original set of values
+# contained 20 integers and we still have 20 steps in the sequence. To increase the number of steps to 40 you would
+# replace 20 with 40 and subtract 20 rather than 10.
+#
+# The second “For” loop does the same thing but generates a sequence from +1 back to -1.