flaskservo.py

from flask import Flask, render_template_string, request
from time import sleep
import pigpio
from OpenSSL import SSL

# This HTML page + JS will be served when the root path is requested with a GET
TPL = '''
<html>
 <body>
 <button id="connectbtn" onclick="requestPermission()">Connect</button>
 <div id="outputdiv"></div>
 </body>
 <script>
 var output = document.getElementById("outputdiv");
var btn = document.getElementById("connectbtn");
var socket = false;
var vertical = 0;
var horizontal = 0;
function sendToFlask()
{
 const xmlhttpreq = new XMLHttpRequest();
 const data = new FormData();
 data.append("updown", vertical);
 data.append("leftright", horizontal);
 xmlhttpreq.open("POST", "campan");
 xmlhttpreq.send(data);
}
function handleRotation(event)
{
 vertical = Math.round(event.gamma);
 horizontal = Math.round(event.beta);
}
function requestPermission()
{
 if (typeof(DeviceMotionEvent) !== 'undefined' && typeof(DeviceMotionEvent.requestPermission) ===
'function')
 {
 DeviceMotionEvent.requestPermission().
then(response => {
 if (response === 'granted') {
 window.addEventListener('deviceorientation', handleRotation);
 }
 finishRequest();
 }).catch(console.error);
 }
 else
 {
 window.addEventListener('deviceorientation', handleRotation);
 finishRequest();
 }
}
function finishRequest()
{
 setInterval(Flask, 200);
}
// schedule the first one.
setTimeout(processVideo, 0);
 </script>
</html>
'''

# The servos are connected on these GPIO pins (BCM numbering)
HORIZ_SERVO_PORT = 13
VERT_SERVO_PORT= 11

HORIZ_SERVO_CENTER = 1750
VERT_SERVO_CENTER = 1500

# Create Flask App
app = Flask(__name__)

# GPIO Info
gpio = pigpio.pi()

def setupGPIO():
    gpio.set_servo_pulsewidth(HORIZ_SERVO_PORT, 0)
    gpio.set_servo_pulsewidth(VERT_SERVO_PORT, 0)

def setServoDuty(servo, duty):
    gpio.set_servo_pulsewidth(servo, duty)

def clamp(num, minimum, maximum):
    return max(min(num, maximum), minimum)

# Serve the HTML file when the root path is requested
@app.route("/")
def serveRoot():
    return render_template_string(TPL)

# Expose an endpoint for sending the servo coordinates
# from the JS to the Flask Backend
@app.route("/moveservos", methods=["POST"])
def moveServos():
    # Get the values from the request
    horizontal = 25 * int(request.form["updown"])
    vertical = 25 * int(request.form["leftright"])
    print(str(horizontal) + ", " + str(vertical))

    # Move the Servos
    setServoDuty(HORIZ_SERVO_PORT, clamp(HORIZ_SERVO_CENTER - horizontal, 500, 2500))
    setServoDuty(VERT_SERVO_PORT, clamp(VERT_SERVO_CENTER - vertical, 500, 2500))

    # Wait for 0.2s so that the servos have time to move
    sleep(0.2)

    # Stop the servo motors to save energy and reduce noise
    gpio.set_servo_pulsewidth(HORIZ_SERVO_PORT, 0)
    gpio.set_servo_pulsewidth(VERT_SERVO_PORT, 0)

    # Return empty request (Should return a 200 OK with an empty body)
    return ""

# Run the app on the local development server

# Accept any IP address
# Create ad-hoc SSL encryption (needed for iOS 13 support)
if __name__ == "__main__":
    app.run(host="192.168.0.157", port=5001, ssl_context='')