Hello friends,
in this web site we can see how we can control a set of lights through an application, Firebase and Raspberry Pi:
In this topic we will see how we can turn on/off an LED from the application using Firebase. We will also see how we can obtain the status of a PushButton in real time.
I will use:
- Android 9
- Raspberry 3 Model B.
- Connection to a router (by Wifi or cable)
- Raspbian 10 (buster)
- Python 3.
- Firebase realtime.
- LED. PushButton.
From Firebase you need (You can also see it on the website indicated above):
- App Inventor.
p9i_raspberry_firebase_boton.aia (2.7 KB)
In Designer:
Blocks:
- When you Click a Button in App or no press PushButton in Raspberry, Firebase gets:
2 Likes
- Raspberry code. Python. Pyrebase.
You need:
pi@raspberrypi:~ $ python3 -V
Python 3.7.3
pi@raspberrypi:~ $ pip --version
pip 18.1 from /usr/lib/python2.7/dist-packages/pip (python 2.7)
If you don't have pip, you can install it:
pi@raspberrypi:~ $ curl https://bootstrap.pypa.io/get-pip.py | python3
You also need "Pyrebase", to communicate Python with Firebase.
pi@raspberrypi:~ $ sudo pip 3 install Pyrebase
-
In Raspbian we have a text editor for Python.
-
Paste this code (Change apiKey, authDomain, databaseURL and storageBucket) :
# Juan A. Villalpando
# http://kio4.com/raspberry/9_firebasedb.htm
import RPi.GPIO as GPIO
import pyrebase
from time import sleep
config = {
"apiKey": "AIzaSyAo9cEmTy2pOEygEEIXdCUHc7uOlSFdcW4",
"authDomain": "kio4-3c240",
"databaseURL": "https://kio4-3c240.firebaseio.com/",
"storageBucket": "project-293607155139"
}
firebase = pyrebase.initialize_app(config)
LED22 = 22 # Terminal by number, el 22 es el GPIO25.
PushButton18 = 18 # Terminal by number, el 18 es el GPIO24.
# El otro terminal a GND.
GPIO.setmode(GPIO.BOARD) # Terminal by number.
GPIO.setwarnings(False)
GPIO.setup(LED22,GPIO.OUT)
GPIO.setup(PushButton18, GPIO.IN, pull_up_down=GPIO.PUD_UP)
print("Inicio. (CTRL + C para salir.")
try:
while True: # Bucle principal
database = firebase.database()
ProjectBucket = database.child("project-293607155139")
estadoLED22 = ProjectBucket.child("LED").get().val()
# print(estadoLED22)
if str(estadoLED22) == "\"OFF\"":
print("LED22 now is OFF.")
GPIO.output(LED22, GPIO.LOW)
else:
print("LED22 now is ON.")
GPIO.output(LED22, GPIO.HIGH)
if GPIO.input(PushButton18) == GPIO.HIGH:
print("PushButton not pressed.")
ProjectBucket.child("project-293607155139").child("PushButton").set("no_pressed.")
else:
print("PushButton pressed.")
ProjectBucket.child("project-293607155139").child("PushButton").set("PRESSED.")
except KeyboardInterrupt: # Salir con CTRL+C
print("Salida.")
GPIO.cleanup() # Limpiar GPIO
- Connections.
2 Likes
- A Slider in the app, moves a servo.
A Slider in the app sends a value to Firebase, Raspberry takes that value and moves a Servo.
p9i_raspberry_firebase_Slider.aia (3.0 KB)
# Juan A. Villalpando
# http://kio4.com/raspberry/9_firebasedb.htm
import RPi.GPIO as GPIO
import pyrebase
from time import sleep
config = {
"apiKey": "AIzaSyAo9cEmTy2pOEygEEIXdCUHc7uOlSFdcW4",
"authDomain": "kio4-3c240",
"databaseURL": "https://kio4-3c240.firebaseio.com/",
"storageBucket": "project-293607155139"
}
firebase = pyrebase.initialize_app(config)
LED22 = 22 # Terminal by number, el 22 es el GPIO25.
PushButton18 = 18 # Terminal by number, el 18 es el GPIO24.
# El otro terminal a GND.
Servo40 = 40 # Terminal by number, el 40 es el GPIO21.
GPIO.setmode(GPIO.BOARD) # Terminal by number.
GPIO.setwarnings(False)
GPIO.setup(LED22,GPIO.OUT)
GPIO.setup(PushButton18, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(Servo40,GPIO.OUT)
pwm=GPIO.PWM(40,50) # pin 40 a 50 Hz
pwm.start(0)
valorServo40 = 90
def SetAngle(angle):
duty = angle / 18 + 2
GPIO.output(40,True)
pwm.ChangeDutyCycle(duty)
sleep(1)
GPIO.output(40,False)
pwm.ChangeDutyCycle(0)
print("Inicio. (CTRL + C para salir.")
try:
while True: # Bucle principal
database = firebase.database()
ProjectBucket = database.child("project-293607155139")
estadoLED22 = ProjectBucket.child("LED").get().val()
print(estadoLED22)
valorServo40 = ProjectBucket.child("project-293607155139").child("Servo").get().val()
print(valorServo40)
if str(estadoLED22) == "\"OFF\"":
print("LED22 now is OFF.")
GPIO.output(LED22, GPIO.LOW)
else:
print("LED22 now is ON.")
GPIO.output(LED22, GPIO.HIGH)
if GPIO.input(PushButton18) == GPIO.HIGH:
print("PushButton not pressed.")
ProjectBucket.child("project-293607155139").child("PushButton").set("no_pressed.")
else:
print("PushButton pressed.")
ProjectBucket.child("project-293607155139").child("PushButton").set("PRESSED.")
SetAngle(int(valorServo40)) # Cámbia el ángulo
# pwm.stop()
except KeyboardInterrupt: # Salir con CTRL+C
print("Salida.")
GPIO.cleanup() # Limpiar GPIO
- Raspberry generates two random numbers, sends them to Firebase, the application receives them.
- Raspberry generates temperature (0 ... 100) and pressure (0 ... 700).
# Juan A. Villalpando
# http://kio4.com/raspberry/9_firebasedb.htm
import RPi.GPIO as GPIO
import pyrebase
from time import sleep
# generate random integer values
from random import seed
from random import randint
config = {
"apiKey": "AIzaSyAo9cEmTy2pOEygEEIXdCUHc7uOlSFdcW4",
"authDomain": "kio4-3c240",
"databaseURL": "https://kio4-3c240.firebaseio.com/",
"storageBucket": "project-293607155139"
}
firebase = pyrebase.initialize_app(config)
database = firebase.database()
ProjectBucket = database.child("project-293607155139")
temperatura = 50
presion = 350
print("Inicio. (CTRL + C para salir.)")
try:
while True: # Bucle principal
temperatura = randint(0, 100)
presion = randint(0, 700)
ProjectBucket.child("project-293607155139").child("temperatura").set(temperatura)
ProjectBucket.child("project-293607155139").child("presion").set(presion)
sleep(4)
except KeyboardInterrupt: # Salir con CTRL+C
print("Salida.")
GPIO.cleanup() # Limpiar GPIO
-
I use two types of Gauges, through a Canvas with two ImageSprites and through Google Chart.
-
The Canvas has as background image: gauge_firebase1.png.
For the needles we used two ImageSprites with a transparent background.
p9i_raspberry_firebase_temperatura.aia (176.9 KB)
Summary
<html><head>
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
// Juan A. Villalpando
// http://kio4.com/raspberry/9_firebasedb.htm
google.charts.load('current', {'packages':['gauge']});
google.charts.setOnLoadCallback(drawChart);
temp_hume = window.AppInventor.getWebViewString().split(":");// Entrada de datos.
temperatura = temp_hume[0];
humedad = temp_hume[1];
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Label', 'Value'],
['Temp', 50],
]);
var options = {
width: 400, height: 120,
redFrom: 90, redTo: 100,
yellowFrom:75, yellowTo: 90,
minorTicks: 5
};
var chart = new google.visualization.Gauge(document.getElementById('chart_div_1'));
///////////////////////////////////////////////
var data2 = google.visualization.arrayToDataTable([
['Label', 'Value'],
['Pres', 350],
]);
var options2 = {
width: 400, height: 120,
greenFrom: 0, greenTo: 180,
redFrom: 600, redTo: 700,
yellowFrom:490, yellowTo: 600,
minorTicks: 5,
max: 700
};
var chart2 = new google.visualization.Gauge(document.getElementById('chart_div_2'));
///////////////////////////////////////////////
chart.draw(data, options);
data.setValue(0, 1, temperatura);
chart.draw(data, options);
chart2.draw(data2, options2);
data2.setValue(0, 1, humedad);
chart2.draw(data2, options2);
};
</script>
</head>
<body>
<div id="chart_div_1" style="width: 400px; height: 120px;"></div>
<div id="chart_div_2" style="width: 400px; height: 120px;"></div>
</body></html>
1 Like
Hi, there! My project is the same as yours using firebase with MIT and wondering if you could help me out? I'm just a beginner though I understand how to connect them, I can't just pick up the logic on the looping side. If I clicked the button, the servo just kept moving non-stop.
Could you please show me how to put a button that can move the servo to 90 degrees every time I clicked this button from the mobile app, please? Thanks a lot.
