Firebase_to_ThermalPrinter.py

import serial
uart = serial.Serial("/dev/serial0", baudrate=19200, timeout = 3000)

import firebase_admin
from firebase_admin import credentials
from firebase_admin import db

import adafruit_thermal_printer
ThermalPrinter = adafruit_thermal_printer.get_printer_class(2.69)

# Fetch the service account key JSON file contents
cred = credentials.Certificate('secret.json')
# Initialize the app with a service account, granting admin privileges
firebase_admin.initialize_app(cred, {
    'databaseURL': "https://saferheart-c5f98-default-rtdb.firebaseio.com"
})


printer = ThermalPrinter(uart)

ref = db.reference('SAFERHEART')

ref = db.reference('SAFERHEART')

myData = ref.get()


#bprint(myData)
#print(myData['-NUzVu3L4BeSRk-2K8zp']['messageContent'])
keys = (list(myData.keys()))
#print(keys)

# for key in keys:
#     print(myData[key]['messageContent'])

currentMessage = len(keys)-1
#print(currentMessage)

nowPrinting = (myData[keys[currentMessage]]['messageContent'])
print(nowPrinting)

printer.print(nowPrinting)
printer.feed(4)