The Raspberry Pi Masterclass & Resources

Wayne / Devscover

Cover Image for The Raspberry Pi Masterclass & Resources

Wayne / Devscover

August 26, 2021

Raspberry Pi Masterclass Resources

I have launched a Raspberry Pi Masterclass. You can find the course here - Raspberry Pi Masterclass

This course will take you from noob to Raspberry Pi expert - no prior experience neccesary.

Here are the code resources for the course.

Pi Webcam

import io
import picamera
import logging
import socketserver
from threading import Condition
from http import server

PAGE="""\
<html>
<head>
<title>Raspberry Pi - Surveillance Camera</title>
</head>
<body>
<center><h1>Raspberry Pi - Surveillance Camera</h1></center>
<center><img src="stream.mjpg" width="640" height="480"></center>
</body>
</html>
"""

class StreamingOutput(object):
    def __init__(self):
        self.frame = None
        self.buffer = io.BytesIO()
        self.condition = Condition()

    def write(self, buf):
        if buf.startswith(b'\xff\xd8'):
            # New frame, copy the existing buffer's content and notify all
            # clients it's available
            self.buffer.truncate()
            with self.condition:
                self.frame = self.buffer.getvalue()
                self.condition.notify_all()
            self.buffer.seek(0)
        return self.buffer.write(buf)

class StreamingHandler(server.BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == '/':
            self.send_response(301)
            self.send_header('Location', '/index.html')
            self.end_headers()
        elif self.path == '/index.html':
            content = PAGE.encode('utf-8')
            self.send_response(200)
            self.send_header('Content-Type', 'text/html')
            self.send_header('Content-Length', len(content))
            self.end_headers()
            self.wfile.write(content)
        elif self.path == '/stream.mjpg':
            self.send_response(200)
            self.send_header('Age', 0)
            self.send_header('Cache-Control', 'no-cache, private')
            self.send_header('Pragma', 'no-cache')
            self.send_header('Content-Type', 'multipart/x-mixed-replace; boundary=FRAME')
            self.end_headers()
            try:
                while True:
                    with output.condition:
                        output.condition.wait()
                        frame = output.frame
                    self.wfile.write(b'--FRAME\r\n')
                    self.send_header('Content-Type', 'image/jpeg')
                    self.send_header('Content-Length', len(frame))
                    self.end_headers()
                    self.wfile.write(frame)
                    self.wfile.write(b'\r\n')
            except Exception as e:
                logging.warning(
                    'Removed streaming client %s: %s',
                    self.client_address, str(e))
        else:
            self.send_error(404)
            self.end_headers()

class StreamingServer(socketserver.ThreadingMixIn, server.HTTPServer):
    allow_reuse_address = True
    daemon_threads = True

with picamera.PiCamera(resolution='640x480', framerate=24) as camera:
    output = StreamingOutput()
    #Uncomment the next line to change your Pi's Camera rotation (in degrees)
    #camera.rotation = 90
    camera.start_recording(output, format='mjpeg')
    try:
        address = ('', 8000)
        server = StreamingServer(address, StreamingHandler)
        server.serve_forever()
    finally:
        camera.stop_recording()

Smart Home Temperature Reader

sudo pip3 install adafruit-circuitpython-dht sudo apt-get install libgpiod2

import time
import board
import adafruit_dht
 
dhtDevice = adafruit_dht.DHT11(board.D4, use_pulseio=False)
 
while True:
    try:
        temperature_c = dhtDevice.temperature
        temperature_f = temperature_c * (9 / 5) + 32
        humidity = dhtDevice.humidity
        print(
            "Temp: {:.1f} F / {:.1f} C    Humidity: {}% ".format(
                temperature_f, temperature_c, humidity
            )
        )
 
    except RuntimeError as error:
        # Errors happen fairly often, DHT's are hard to read, just keep going
        print(error.args[0])
        time.sleep(2.0)
        continue
    except Exception as error:
        dhtDevice.exit()
        raise error
 
    time.sleep(2.0)

Smart Home Web Server

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello world'

@app.route('/hello/<name>')
def hello(name):
    return render_template('index.html', name=name)

if __name__ == '__main__':
    app.run(debug=True, host='0.0.0.0')

<html>
<body>
<h1>Welcome {{ name }}</h1>
</body>
</html>

Home Temperature Web Page

<html>
<body>
<h1>Welcome To Our Smart Home Weather System</h1>
<h2>Temperature: {{ temperature }} C</h2>
<h2>Humidity: {{ humid }}%</h2>
</body>
</html>

from flask import Flask, render_template
import time
import board
import adafruit_dht

dhtDevice = adafruit_dht.DHT11(board.D4, use_pulseio=False)
app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello World!'

@app.route('/temperature')
def temp():
    try:
        temp_c = dhtDevice.temperature
        temp_f = temp_c * (9 / 5) + 32
        humid = dhtDevice.humidity
        return render_template('temperature.html', temperature=temp_c, humid=humid)
    except RuntimeError as error:
        return error.args[0]
    except Exception as error:
        dhtDevice.exit()
        raise error

@app.route('/hello/<name>')
def hello(name):
    return render_template('index.html', name=name)

if __name__ == '__main__':
    app.run(debug=True, host='0.0.0.0')