abishevs/wifi-car-with-raspberry-pi4

Flask app with raspb camera view to control and see arduino based RC car from a browser.

If venv (virutal envierement) is not installed.

sudo apt install python3.10-venv

if just cloned make an virtual envierament

python3 -m venv ./flask-env

start virtual envierement.

source flask-env/bin/activate

then install dependencies

pip install -r requirements.txt

To deactivate type

deactivate

Start the server with debug mode set to True

python3 flask-ard-car.py

To update requirements.txt type this

pip freeze > requirements.txt

Conection frontend to backend

• Using ajax and javascript to send data on every button click or keystroke press.
• Keystrokes(wasd and arrows, space or escape for stop) P.S speed up and down not implemnted yet

Future fix of delay from frontend

Use socket.io and get bi-direcation connection to the server. This way sending data will be very low latency.

wifi-car-with-raspberry-pi4's Issues

video lags

i see video on page but it is bit too laggy.
so i tried to rewrite two parts of camera.py:

from picamera.array import PiRGBArray
from picamera import PiCamera
class VideoCamera(object):
    def __init__(self, flip = False, file_type = ".jpg", photo_string = "photo-taken"):
        #self.vs = PiVideoStream(resolution=(640, 480), framerate=30)
        self.vs = PiCamera(resolution=(640, 480), framerate=30)
        self.rawCapture = PiRGBArray(self.vs)
        
        #self.vs.start()
        #self.vs = PiVideoStream().start()

and

def get_frame(self):
        #frame = self.flip_if_needed(self.vs.read())
        for frame in self.vs.capture_continuous(self.rawCapture, format="bgr"):
            #ret, jpeg = cv.imencode(self.file_type, frame)
            self.rawCapture.truncate(0) 
            self.image = frame.array
            ret, jpeg = cv.imencode(self.file_type, self.image)            
            #self.previous_frame = jpeg
            return jpeg.tobytes()

dont know if it start working a bit faster...
may be a better solution is io.BytesIO()
https://stackoverflow.com/questions/40065328/picameravalueerror-incorrect-buffer-length-for-resolution-1920x1080

async key strokes from website

hi!
thanks for code. i use it in raspberry pi zero 2.

as far as i understand the main logic of control is here:

def retrieve_data():
    id = request.args.get('id', 0)
    id = int(id)
    print(f"Recieved from the web id: {id}")
    if 1 <= id <= 5:
        write_to_arduino(id)

i have changed for my case this way (as i have no arduino and made direct connection to motor driver):

def retrieve_data():
    id = request.args.get('id', 0)
    id = int(id)
    print(f"Recieved from the web id: {id}")
    if 1 <= id <= 5:
        #write_to_arduino(id)
        if id==4:
            setServoAngle(servo, 140)
        if id==5:
            setServoAngle(servo, 90)
        if id==1:
            mov.Forward(speed)
        if id==2:
            mov.Backward(speed)
        if id==3:
            mov.Stop()

but as i see there is synchronous code and when one key pressed there is no way to press another at the same time.
are you planning to add something async?