Tray in/out Code Documentation

This code documentation will walk you through the main processing logic on how we retrieve the data from our sensors

Tray Out

MIFAREReader = MFRC522.MFRC522()

GPIO.setup(7, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

db = MongoClient("mongodb+srv://root:0NqePorN2WDm7xYc@cluster0.fvp4p.mongodb.net/iot?retryWrites=true&w=majority")

# Welcome message
print("RFID Detected!")
print("FSR Detected")

# This loop keeps checking for chips. If one is near it will get the UID and authenticate
try:
    process_status = True
    while continue_reading:
        # Scan for cards
        (status,TagType) = MIFAREReader.MFRC522_Request(MIFAREReader.PICC_REQIDL)
        # If a card is found
        rfid_status = 0 # default for rfid
       
        # Get the UID of the card
        (status,uid) = MIFAREReader.MFRC522_Anticoll()
        current_time = datetime.now()
        print("Time is: " + str(current_time))
        fsr_status = GPIO.input(7)
        print("Weight sensor: " + str(fsr_status))

        if status == MIFAREReader.MI_OK and process_status and fsr_status == 1:
            print("RFID and Weight Dected")
            rfid_status = 1 # rfid tag detected
            posts = db.fsr_rfid.collection
            post_data = {
                'timestamp': current_time,
                'rfid_status': rfid_status,
                'fsr_status': fsr_status
            }
            result = posts.insert_one(post_data)
            print("Inserted with ID: " + str(result))
            process_status = False

        if fsr_status == 0:
            print("Tray not detected")
            process_status = True
        time.sleep(2)

except:
    print("Something went wrong")

We use MFRC522 library to get the RFID reader readings, and we retrieve data from the GPIO input 7 port.

We validate the data and determine whether there is a tray detected.

Tray In

pir_sensor = 7
motion=0
grovepi.pinMode(pir_sensor,"INPUT")
GPIO.setmode(GPIO.BOARD)

GPIO.setup(7, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)


countTray = False
fsr_bool = False
while True:
	try:
            fsr_status  = GPIO.input(7)
            print("Weight sensor: " + str(fsr_status))
            # Sense motion, usually human, within the target range
            motion=grovepi.digitalRead(pir_sensor)
            if motion==0 or motion==1:	# check if reads were 0 or 1 it can be 255 also because of IO Errors so remove those values
                if motion == 1 and countTray and fsr_status == 0:
                    current_time = datetime.now()
                    tray_in = db.fsr_rfid.tray_in
                    post_data = {
                        'status_count': -1,
                        'timestamp': current_time,
                    }
                    result = tray_in.insert_one(post_data)
                    print("Stack of Trays removed")
                    countTray = False
                if motion==1:
                    if(fsr_status == 1):
                        countTray = True
                    print ('Motion Detected')
                if(motion == 0 and countTray):
                        current_time = datetime.now()
                        tray_in = db.fsr_rfid.tray_in
                        post_data = {
                            'status_count': 1,
                            'timestamp': current_time,
                        }
                        result = tray_in.insert_one(post_data)
                        print("Tray in counted")
                        countTray = False
            time.sleep(2)

	except IOError:
		print ("Error")
    

We use grovepi.pinMode() to fix the pin value for motion sensor to retrieve all the motion readings

We validate the motion and force data to determine whether there is a tray detected, we check whether it is a tray into the trolley or removal of tray from the trolley so to prevent any double counting.