Launcher code

launcher_servo.py

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+import time
+import RPi.GPIO as GPIO
+
+# Set pin numbering convention
+GPIO.setmode(GPIO.BCM)
+
+# Choose appropriate pwm channels to be used to control the servos
+cont_servo = 18
+half_servo = 20
+
+# Configure the servo pins to output
+GPIO.setup(cont_servo, GPIO.OUT)
+GPIO.setup(half_servo, GPIO.OUT)
+
+# Initialise the servo pins to output pwm with 50 Hz frequency
+cont = GPIO.PWM(cont_servo, 50)
+half = GPIO.PWM(half_servo, 50)
+
+# For a continuous rotation servo, altering duty cycle / pulse width
+# controls the speed of rotation of the servo, not the position of the shaft.
+
+# Both motors for cont and half are continuous rotation servos
+
+# SG92R 360 by Continental & FEETECH FS90R (cont)
+# 100% counterclockwise speed = 1 ms pulse width = 5% duty cycle (for 50 Hz = 20 ms)
+# Stop = around 1.5 ms pulse width = around 7.5% duty cycle (for 50 Hz = 20 ms)
+# 100% clockwise speed = 2 ms pulse width = 10% duty cycle (for 50 Hz = 20 ms)
+# May require some simple calibration:
+# Output the desired stop duty cycle to the servo
+# Then gently adjust the potentiometer in the recessed hole with a small screwdriver until the servo stops moving.
+
+# SPT5535LV-360W (half)
+# 100% counterclockwise speed = 0.5 - 0.95 ms pulse width = around 2.5% - 4.75% duty cycle (for 50 Hz = 20 ms)
+# Stop = between 1.45 - 1.55 ms pulse width = around 7.25% - 7.75% duty cycle (for 50 Hz = 20 ms)
+# 100% clockwise speed = 1.95 - 2.5 ms pulse width = around 9.75% - 12.5% duty cycle (for 50 Hz = 20 ms)
+
+half.start(7.25)    # The pin starts to output PWM signals at 50 Hz with an initial duty cycle of 7.5% which corresponds to stop for a continuous rotation servo
+time.sleep(1)      # The delay is to allow time for the servo to react
+cont.start(7.5)    
+time.sleep(1)      
+
+# Flip PVC pipe upright
+half.ChangeDutyCycle(6) # slow counterclockwise
+time.sleep(3.25) # Calibrated time to rotate approximately 180 assuming 61 RPM
+half.ChangeDutyCycle(7.25)
+time.sleep(2.5)
+
+# Flip PVC pipe back down test code
+# half.ChangeDutyCycle(9.75) # slow clockwise
+# time.sleep(0.5) # Calibrated time to rotate approximately 180 assuming 61 RPM
+# half.ChangeDutyCycle(7.25)
+# time.sleep(2.5)
+
+# Rotate the continuous rotation servo
+cont.ChangeDutyCycle(10) # 100% clockwise
+time.sleep(3.25)  # Rotate for 3.25 sec
+cont.ChangeDutyCycle(7.5) # Stop
+time.sleep(2.5)
+
+# Cleanup
+cont.stop()
+half.stop()
+GPIO.cleanup()

launcher_servo_reverse.py

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+import time
+import RPi.GPIO as GPIO
+
+GPIO.setmode(GPIO.BCM)
+
+cont_servo = 18
+half_servo = 20
+
+GPIO.setup(cont_servo, GPIO.OUT)
+GPIO.setup(half_servo, GPIO.OUT)
+
+cont = GPIO.PWM(cont_servo, 50)
+half = GPIO.PWM(half_servo, 50)
+
+half.start(7.25)
+time.sleep(1)
+cont.start(7.5)
+time.sleep(1)
+
+cont.ChangeDutyCycle(5) # 100% counterclockwise
+time.sleep(3.25)
+cont.ChangeDutyCycle(7.5)
+time.sleep(2.5)
+
+#half.ChangeDutyCycle(8) # slow clockwise
+#time.sleep(2)
+#half.ChangeDutyCycle(7.25)
+#time.sleep(2.5)
+
+cont.stop()
+half.stop()
+GPIO.cleanup()
+
+