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Last active Mar 17, 2020
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Python script for the Car-IOTA tutorial part 1
# Imports some required PyOTA libraries
import iota
from iota import Address
# Imports some libraries required by OpenALPR communication
import requests
import base64
import json
# Imports the CSV library used for DB comm.
import csv
# Import PiCamera library
from picamera import PiCamera
# Setup the camera
camera = PiCamera()
# Rotate the image so that the lisence plate is placed horizontaly within the picture
# Depends on how you monted the camera
camera.rotation = 270
# Import the GPIO library
import RPi.GPIO as GPIO
import time
# URL to IOTA fullnode used when interacting with the Tangle
iotaNode = ""
# Hotel owner recieving address, replace with your own recieving address
# Price of the parking service (10 IOTA)
price = 10
# Specify GPIO pins used by ultrasonic sensor
TRIG = 23
ECHO = 24
# Variable used for monitoring when car enters/exits the sensor area
car_found = False
print "Distance Measurement In Progress"
# Setup the GPIO pins
# Function for capturing image using the Raspberry PI camera
def capture_image():
image_file = "/home/pi/Desktop/image.jpg"
print("Capturing image...")
# Function for getting the plate ID from image using the OpenALPR Cloud API service
def get_plate_id(image_file):
# Replace with your OpenALPR secret key
SECRET_KEY = 'PutYourOpenALPRSecretKeyHere'
with open(image_file, 'rb') as image_file:
img_base64 = base64.b64encode(
# Send image to the OpenALPR Cloud service for decoding
url = '' % (SECRET_KEY)
r =, data = img_base64)
# Convert returned json to string
r_str = json.loads(json.dumps(r.json(), indent=2))
# Search the Plate/SEED DB for a matching lisence plate
# If found, get the related SEED
if 'plate' in r_str['results'][0]:
plate_id = r_str['results'][0]['plate']
print('OpenALPR did not return a plate ID')
# Function for getting the seed used for IOTA payment
def get_seed(plate_id):
plate_found = False
with open('plates.csv') as csv_file:
csv_reader = csv.reader(csv_file, delimiter=',')
for row in csv_reader:
if row[0] == plate_id:
plate_found = True
if plate_found == True:
print("Plate was found in DB, seed: " + seed)
send_transaction(hotel_address, price, plate_id, seed)
print("Plate was not found in DB")
# Function for sending the IOTA value transaction
def send_transaction(hotel_address, price, plate_id, seed):
# Define api object
api = iota.Iota(iotaNode, seed=seed)
# Create transaction object
tx1 = iota.ProposedTransaction( address = iota.Address(hotel_address), message = None, tag = iota.Tag(iota.TryteString.from_unicode(plate_id)), value = price)
# Send transaction to tangle
print("\nSending transaction... Please wait...")
SentBundle = api.send_transfer(depth=3,transfers=[tx1], inputs=None, change_address=None, min_weight_magnitude=14)
# Display transaction sent confirmation message
print("\nTransaction sent...")
# Check (every 2 sec.) for new cars entering or exiting the parking lot..
while True:
GPIO.output(TRIG, False)
print "Waiting For Sensor To Settle"
GPIO.output(TRIG, True)
GPIO.output(TRIG, False)
while GPIO.input(ECHO)==0:
pulse_start = time.time()
while GPIO.input(ECHO)==1:
pulse_end = time.time()
pulse_duration = pulse_end - pulse_start
# Convert distance to cm
distance = pulse_duration * 17150
distance = round(distance, 2)
# If distance between sensor and car is less than 10 cm
if distance < 10:
if car_found == False:
car_found = True
car_found = False
except KeyboardInterrupt: # If there is a KeyboardInterrupt (when you press ctrl+c), exit the program and cleanup
print("Cleaning up!")
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