PRE2017 3 11 Python Code: Difference between revisions

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==Pin/servo Control==
__NOTOC__
==QR scanner with cylinder and platform response==
The main script scans QR codes in front of the camera, opens the cylinder and moves the platform down if a correct code is presented.
===Import required packages===
<pre>
<pre>
import RPi.GPIO as GPIO     # GPIO pin control
#!/usr/bin/python
import time                 # Posibility to delay
from pyzbar.pyzbar import decode # QR reader
GPIO.setmode(GPIO.BOARD)   # Board numbering sceme
from PIL import Image              # Image reader
pin_cServo1 = 29            # Continuous servo 1
import cv2                    # Image reader
pin_cServo2 = 33            # Continuous servo 2
import RPi.GPIO as GPIO       # GPIO pin control
pin_cServo3 = 37           # Continuous servo 3
import time               # Posibility to delay
pin_mServo1 = 13            # Mini servo 1
import signal # Cleanup when ending script
import sys # Needed to stop script if no camera
</pre>
 
===Set up constants===
 
<pre>
pin_s1  = 29 # Continuous servo 1
pin_s2  = 33            # Continuous servo 2
freq = 50        # Continuous servo frequency [Hz]
 
s1left  = 5.00        # 100% velocity to left
s1center = 6.70        # no movement
s1right  = 8.00        # 100% velocity to right
 
s2left  = 5.00        # 100% velocity to left
s2center = 6.60        # no movement
s2right  = 8.00        # 100% velocity to right
 
cyldelay      = 2 # Time it takes for cylinder to rotate
dropdelay    = 5    # Time it takes to drop package
pauzedelay    = 2 # Time between cylinder rotation and platform movement
platformdelay = 2    # Time it takes for platform to move down
 
imgname = "image2.jpg"  # File frame is temporarily saved in
</pre>
===Imports access codes===
<pre>
# Imports allowed QRcodes
passcodelist = []
with open("authcodes") as file:
passcodelist = [line.strip() for line in file]
</pre>
 
===Stops the script safely if CTRL+C is pressed===
 
<pre>
# Releases pins when script is interrupted
def end_run(signal,frame):
global running
print("Ctrl+C captured, ending script")
running = False
servo1.stop()
servo2.stop()
GPIO.cleanup()
 
# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)
</pre>
 
===Takes a picture with the camera===
 
<pre>
# Takes picture from camera, reads and evaluates QRcode
def QRscanner(passcodelist, camslot):
camera = cv2.VideoCapture(camslot) # Initializes camera viewer
grabbed, im = camera.read()    # Reads figure
</pre>
 
===Checks if a picture is taken, and if it is not, it looks for other cameras or stops the script===
 
<pre>
if not grabbed: # Searches for working camera
if camslot < 5:
camstr = "No camera connected in slot: " + str(camslot)
print(camstr)
camslot = camslot + 1
return False, camslot
else:
print("No camera connected")
servo1.stop()
servo2.stop()
GPIO.cleanup()
sys.exit()
</pre>
 
===Reads QR-codes in the image and checks if a correct code is presented===
 
<pre>
cv2.imwrite(imgname,im) # Converts image to jpg
img = Image.open(imgname) # Reads jpg
decodedObjects = decode(img)    # Decodes image
for obj in decodedObjects:    # Makes sure every code is read
  qrdata = obj.data      # Reads the alphanumerical code
for passcode in passcodelist:
    if passcode in qrdata:      # Verifies if code is legit
print("Correct code, cylinders start opening")
        return True, camslot
else:
print("Wrong code")
return False, camslot
</pre>
 
===Sets up the output pins that control the servos===
 
<pre>
GPIO.setmode(GPIO.BOARD)   # Board numbering sceme pins
GPIO.setup(pin_s1, GPIO.OUT) # Sets pins as output
GPIO.setup(pin_s2, GPIO.OUT)
servo1 = GPIO.PWM(pin_s1, freq) # Assigns frequency to pins
servo2 = GPIO.PWM(pin_s2, freq)
servo1.start(s1center) # Starts servos in neutral position
servo2.start(s2center)
</pre>
 
===Sets up variables, starts the script, and runs the QR-code reader until correct code is presented or CTRL+C is pressed===
 
<pre>
camslot = 0 # Default camera slot
running = True
print("Program Running, provide QR-code")
 
while running:
rightcode, camslot = QRscanner(passcodelist, camslot)  # Runs QR-reader
</pre>
 
===Opens/closes the cylinder and moves down the platform===
 
<pre>
if rightcode:
servo1.ChangeDutyCycle(s1right) # Cylinders open
    time.sleep(cyldelay)            # Duration of cylinder movement
    servo1.ChangeDutyCycle(s1center) # Cylinders stop moving
print("Cylinders are open, package can be dropped")
    time.sleep(dropdelay)           # Duration of package dropping
    print("Package dropped, cylinders start closing")
servo1.ChangeDutyCycle(s1left)  # Cylinders close
  time.sleep(cyldelay)            # Duration of cylinder movement
    servo1.ChangeDutyCycle(s1center) # Cylinders stop moving
print("Cylinders are closed")
time.sleep(pauzedelay)          # Time buffer
print("Platform starts moving down")
servo2.ChangeDutyCycle(s2right)  # Platform moves down
    time.sleep(platformdelay)        # Duration of platform movement
    servo2.ChangeDutyCycle(s2center) # Platform stops moving
print("Platform stopped moving down, new code can be scanned")
</pre>
 
==Calibrator==
In order to make sure that the servos rotated exactly long enough, a python script was written which starts and stops the servos on the press of a button:
 
<pre>
import RPi.GPIO as GPIO # GPIO pin control
import signal # Cleanup when ending script


# Sets pin as output.
# Releases pins when script is interrupted
GPIO.setup(cServo1,GPIO.OUT)
def end_run(signal,frame):
GPIO.setup(cServo2,GPIO.OUT)  
global running
GPIO.setup(cServo3,GPIO.OUT)  
print("Ctrl+C captured, ending script")
GPIO.setup(mServo1,GPIO.OUT)  
running = False
servo1.stop()
servo2.stop()
GPIO.cleanup()


freq = 100                  # Servo frequency [Hz]
# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)


# Assigns frequency to pins
pin_s1  = 29 # Continuous servo 1
cServo1 = GPIO.PWM(pin_cServo1, freq)
pin_s2  = 33            # Continuous servo 2
cServo2 = GPIO.PWM(pin_cServo2, freq)
freq = 50 # Continuous servo frequency [Hz]
cServo3 = GPIO.PWM(pin_cServo3, freq)
mServo1 = GPIO.PWM(pin_mServo1, freq)


cleft   = 5             # 100% velocity to left  
s1left   = 5.00        # 100% velocity to left
ccenter = 7.5          # no movement
s1center = 6.70        # no movement
cright = 10            # 100% velocity to right
s1right = 8.00        # 100% velocity to right


mleft   = 5             # 90 degrees left
s2left   = 5.00        # 100% velocity to left
mcenter = 7.5          # center
s2center = 6.60        # no movement
mright = 10            # 90 degrees right
s2right = 8.00        # 100% velocity to right


cyldelay        = 2    # Time it takes for cylinder to rotate
GPIO.setmode(GPIO.BOARD)
dropdelay      = 15    # Time it takes to drop package
GPIO.setup(pin_s1,GPIO.OUT)
platformdelay  = 2    # Time it takes for platform to move down
GPIO.setup(pin_s2,GPIO.OUT)
lockdelay      = 20    # Time lock stays opened
servo1 = GPIO.PWM(pin_s1,freq)
servo2 = GPIO.PWM(pin_s2,freq)


# Sets all servos still at centered position
servo1.start(s1center) # Starts servos in neutral position
cServo1.start(ccenter)
servo2.start(s2center)
cServo2.start(ccenter)
cServo3.start(ccenter)
mServo1.start(mcenter)


if i:
running = True
    cServo1.ChangeDutyCycle(cleft)      # Inner cylinder opens
    cServo2.ChangeDutyCycle(cright)    # Outer cylinder moves away
    time.delay(cyldelay)                # Duration of cylinder movement
    cServo1.ChangeDutyCycle(ccenter)    # Inner Cylinder stops moving
    cServo2.ChangeDutyCycle(ccenter)    # Outer Cylinder stops moving
    time.delay(dropdelay)              # Duration of package dropping
    cServo1.ChangeDutyCycle(cright)    # Inner cylinder closes
    cServo2.ChangeDutyCycle(cleft)      # Outer cylinder moves back
    time.delay(cyldelay)                # Duration of cylinder movement
    cServo1.ChangeDutyCycle(ccenter)
    cServo2.ChangeDutyCycle(ccenter) 
   
    cServo3.ChangeDutyCycle(cleft)      # Platform moves down
    time.delay(platformdelay)          # Duration of platform moving down
    cServo3.ChangeDutyCycle(ccenter)    # Platform stops moving


if j=true:
print("1(l,c,r), 2(l,c,r): ")
     mServo1.ChangeDutyCycle(mleft)     # Lock opens
while running:
     time.delay(lockdelay)
    n = raw_input()
     mServo1.ChangeDutyCycle(mcenter)   # Lock closes
    if n == "1l":
        servo1.ChangeDutyCycle(s1left)
     elif n == "1c":
        servo1.ChangeDutyCycle(s1center)
     elif n == "1r":
        servo1.ChangeDutyCycle(s1right)
    elif n == "2l":
        servo2.ChangeDutyCycle(s2left)
     elif n == "2c":
        servo2.ChangeDutyCycle(s2center)
    elif n == "2r":
        servo2.ChangeDutyCycle(s2right)
</pre>
</pre>
==QRcode reader==
 
==Platform Resetter==  
After the storage box is emptied, the platform has to move back up, which is done with the following python code:
 
<pre>
<pre>
#!/usr/bin/python
import RPi.GPIO as GPIO        # GPIO pin control
from pyzbar.pyzbar import decode    # QR reader
import time
import cv2                          # Image reader
import signal # Cleanup when ending script
import urllib                      # Url reader
 
# Releases pins when script is interrupted
def end_run(signal,frame):
print("Ctrl+C captured, ending script")
servo2.stop()
GPIO.cleanup()
 
# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)
 
 
pin_s2  = 33            # Continuous servo 2
freq = 50        # Continuous servo frequency [Hz]
 
s2left  = 5.00        # 100% velocity to left
 
platformdelay = 4.25    # Time it takes for platform to move down
 
GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin_s2, GPIO.OUT)
servo2 = GPIO.PWM(pin_s2, freq)
servo2.start(s2left)
time.sleep(platformdelay)
servo2.stop()
GPIO.cleanup()
 
</pre>
 
==Cylinder Resetter==
If any failures occur when the cylinder is opened, this script can be activated to close the cylinder:
 
<pre>
import RPi.GPIO as GPIO        # GPIO pin control
import time              # Posibility to delay
import signal # Cleanup when ending script
 
pin_s1  = 29 # Continuous servo 1
freq = 50        # Continuous servo frequency [Hz]
 
s1left  = 5.00        # 100% velocity to left
s1center = 6.70        # no movement
s1right  = 8.00        # 100% velocity to right


cyldelay      = 1.35 # Time it takes for cylinder to rotate


i = 0      # Becomes 1 if QRcode is scanned and correct
# Releases pins when script is interrupted
def end_run(signal,frame):
global running
print("Ctrl+C captured, ending script")
running = False
servo1.stop()
servo2.stop()
GPIO.cleanup()


# Retrieves figure from recorder
# Runs end_run if ctrl+C is clicked
urllib.urlretrieve("http://192.168.178.66:8080/shot.jpg","pic01.jpg")
signal.signal(signal.SIGINT, end_run)
im = cv2.imread("pic01.jpg")        # Reads figure
decodedObjects = decode(im)        # Decodes figure
for obj in decodedObjects:          # Makes sure every code is read
    qrdata = obj.data              # Reads the alphanumerical code
    # Cuts important information out of data and prints it
    qrdata = qrdata.split("Open The Box ")[1]
    qrdata = qrdata[:8]
    print qrdata


    if qrdata == "QL5WST4S":        # Verifies if code is legit
GPIO.setmode(GPIO.BOARD)    # Board numbering sceme pins
        i=1
GPIO.setup(pin_s1, GPIO.OUT) # Sets pins as output
servo1 = GPIO.PWM(pin_s1, freq) # Assigns frequency to pins
servo1.start(s1left) # Starts servos in neutral position
time.sleep(cyldelay)
servo1.stop()
GPIO.cleanup()


# Followup action if code is legit
if i == 1:
    print("success")
    # make motor response here
</pre>
</pre>
==NFC Reader==

Latest revision as of 13:37, 2 April 2018

QR scanner with cylinder and platform response

The main script scans QR codes in front of the camera, opens the cylinder and moves the platform down if a correct code is presented.

Import required packages

#!/usr/bin/python
from pyzbar.pyzbar import decode	# QR reader
from PIL import Image               	# Image reader
import cv2                     		# Image reader
import RPi.GPIO as GPIO    	     	# GPIO pin control
import time               	 	# Posibility to delay
import signal				# Cleanup when ending script
import sys				# Needed to stop script if no camera

Set up constants

pin_s1  = 29		# Continuous servo 1
pin_s2  = 33            # Continuous servo 2
freq 	= 50        	# Continuous servo frequency [Hz]

s1left   = 5.00         # 100% velocity to left
s1center = 6.70         # no movement
s1right  = 8.00         # 100% velocity to right

s2left   = 5.00         # 100% velocity to left
s2center = 6.60         # no movement
s2right  = 8.00         # 100% velocity to right

cyldelay      = 2 	# Time it takes for cylinder to rotate
dropdelay     = 5    	# Time it takes to drop package
pauzedelay    = 2 	# Time between cylinder rotation and platform movement
platformdelay = 2     	# Time it takes for platform to move down

imgname = "image2.jpg"  # File frame is temporarily saved in

Imports access codes

# Imports allowed QRcodes
passcodelist = []
with open("authcodes") as file:
	passcodelist = [line.strip() for line in file]

Stops the script safely if CTRL+C is pressed

# Releases pins when script is interrupted
def end_run(signal,frame):
	global running
	print("Ctrl+C captured, ending script")
	running = False
	servo1.stop()
	servo2.stop()
	GPIO.cleanup()

# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)

Takes a picture with the camera

# Takes picture from camera, reads and evaluates QRcode
def QRscanner(passcodelist, camslot):
	camera = cv2.VideoCapture(camslot)	# Initializes camera viewer
	grabbed, im = camera.read()     	# Reads figure

Checks if a picture is taken, and if it is not, it looks for other cameras or stops the script

	if not grabbed:				# Searches for working camera
		if camslot < 5:
			camstr = "No camera connected in slot: " + str(camslot)
			print(camstr)
			camslot = camslot + 1
			return False, camslot
		else:
			print("No camera connected")
			servo1.stop()
			servo2.stop()
			GPIO.cleanup()
			sys.exit()

Reads QR-codes in the image and checks if a correct code is presented

	cv2.imwrite(imgname,im)		# Converts image to jpg
	img = Image.open(imgname)	# Reads jpg
	decodedObjects = decode(img)    # Decodes image
	for obj in decodedObjects:     	# Makes sure every code is read
	   	qrdata = obj.data       # Reads the alphanumerical code
		for passcode in passcodelist:
    			if passcode in qrdata:      # Verifies if code is legit
				print("Correct code, cylinders start opening")
        			return True, camslot
			else:
				print("Wrong code")
	return False, camslot

Sets up the output pins that control the servos

GPIO.setmode(GPIO.BOARD)    	# Board numbering sceme pins
GPIO.setup(pin_s1, GPIO.OUT)	# Sets pins as output
GPIO.setup(pin_s2, GPIO.OUT)
servo1 = GPIO.PWM(pin_s1, freq)	# Assigns frequency to pins
servo2 = GPIO.PWM(pin_s2, freq)
servo1.start(s1center)		# Starts servos in neutral position
servo2.start(s2center)

Sets up variables, starts the script, and runs the QR-code reader until correct code is presented or CTRL+C is pressed

camslot = 0 		# Default camera slot
running = True
print("Program Running, provide QR-code")

while running:
	rightcode, camslot = QRscanner(passcodelist, camslot)  # Runs QR-reader

Opens/closes the cylinder and moves down the platform

	if rightcode:
		servo1.ChangeDutyCycle(s1right)	 # Cylinders open
    		time.sleep(cyldelay)             # Duration of cylinder movement
    		servo1.ChangeDutyCycle(s1center) # Cylinders stop moving
		print("Cylinders are open, package can be dropped")
    		time.sleep(dropdelay)            # Duration of package dropping
    		print("Package dropped, cylinders start closing")
		servo1.ChangeDutyCycle(s1left)  # Cylinders close
   		time.sleep(cyldelay)             # Duration of cylinder movement
    		servo1.ChangeDutyCycle(s1center) # Cylinders stop moving
		print("Cylinders are closed")
		time.sleep(pauzedelay)           # Time buffer
		print("Platform starts moving down")
		servo2.ChangeDutyCycle(s2right)   # Platform moves down
    		time.sleep(platformdelay)        # Duration of platform movement
    		servo2.ChangeDutyCycle(s2center) # Platform stops moving
		print("Platform stopped moving down, new code can be scanned")

Calibrator

In order to make sure that the servos rotated exactly long enough, a python script was written which starts and stops the servos on the press of a button: 

import RPi.GPIO as GPIO	# GPIO pin control
import signal		# Cleanup when ending script

# Releases pins when script is interrupted
def end_run(signal,frame):
	global running
	print("Ctrl+C captured, ending script")
	running = False
	servo1.stop()
	servo2.stop()
	GPIO.cleanup()

# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)

pin_s1  = 29		# Continuous servo 1
pin_s2  = 33            # Continuous servo 2
freq	= 50		# Continuous servo frequency [Hz]

s1left   = 5.00         # 100% velocity to left
s1center = 6.70         # no movement
s1right  = 8.00         # 100% velocity to right

s2left   = 5.00         # 100% velocity to left
s2center = 6.60         # no movement
s2right  = 8.00         # 100% velocity to right

GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin_s1,GPIO.OUT)
GPIO.setup(pin_s2,GPIO.OUT)
servo1 = GPIO.PWM(pin_s1,freq)
servo2 = GPIO.PWM(pin_s2,freq)

servo1.start(s1center)		# Starts servos in neutral position
servo2.start(s2center)

running = True

print("1(l,c,r), 2(l,c,r): ")
while running:
    n = raw_input()
    if n == "1l":
        servo1.ChangeDutyCycle(s1left)
    elif n == "1c":
        servo1.ChangeDutyCycle(s1center)
    elif n == "1r":
        servo1.ChangeDutyCycle(s1right)
    elif n == "2l":
        servo2.ChangeDutyCycle(s2left)
    elif n == "2c":
        servo2.ChangeDutyCycle(s2center)
    elif n == "2r":
        servo2.ChangeDutyCycle(s2right)

Platform Resetter

After the storage box is emptied, the platform has to move back up, which is done with the following python code: 

import RPi.GPIO as GPIO    	     	# GPIO pin control
import time
import signal				# Cleanup when ending script

# Releases pins when script is interrupted
def end_run(signal,frame):
	print("Ctrl+C captured, ending script")
	servo2.stop()
	GPIO.cleanup()

# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)


pin_s2  = 33            # Continuous servo 2
freq 	= 50        	# Continuous servo frequency [Hz]

s2left   = 5.00         # 100% velocity to left

platformdelay = 4.25     	# Time it takes for platform to move down

GPIO.setmode(GPIO.BOARD)
GPIO.setup(pin_s2, GPIO.OUT)
servo2 = GPIO.PWM(pin_s2, freq)
servo2.start(s2left)
time.sleep(platformdelay)
servo2.stop()
GPIO.cleanup()

Cylinder Resetter

If any failures occur when the cylinder is opened, this script can be activated to close the cylinder: 

import RPi.GPIO as GPIO    	     	# GPIO pin control
import time               	 	# Posibility to delay
import signal				# Cleanup when ending script

pin_s1  = 29		# Continuous servo 1
freq 	= 50        	# Continuous servo frequency [Hz]

s1left   = 5.00         # 100% velocity to left
s1center = 6.70         # no movement
s1right  = 8.00         # 100% velocity to right

cyldelay      = 1.35 	# Time it takes for cylinder to rotate

# Releases pins when script is interrupted
def end_run(signal,frame):
	global running
	print("Ctrl+C captured, ending script")
	running = False
	servo1.stop()
	servo2.stop()
	GPIO.cleanup()

# Runs end_run if ctrl+C is clicked
signal.signal(signal.SIGINT, end_run)

GPIO.setmode(GPIO.BOARD)    	# Board numbering sceme pins
GPIO.setup(pin_s1, GPIO.OUT)	# Sets pins as output
servo1 = GPIO.PWM(pin_s1, freq)	# Assigns frequency to pins
servo1.start(s1left)		# Starts servos in neutral position
time.sleep(cyldelay)
servo1.stop()
GPIO.cleanup()
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