ImportError: no module named 'car'

OpenMV Boards
1

I’m making a code that makes a robot follow a red ball. I’ve got the code from the following video https://youtu.be/e14cx2qFiDk?si=h-IzkDK4yAwuUQj2
I used the codes from the video and named also named them the same. Yet it keeps on giving an error saying: ImportError: no module named ‘car’.

Here is the code that I used:

import sensor, image, time
import car
from pid import PID


sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(10)
sensor.set_auto_whitebal(False)
clock = time.clock()

red_threshold = (55, 80, 20, 70, 0, 25)
size_threshold = 2000
x_pid = PID(p=0.5, i=1, imax=100)
h_pid = PID(p=0.05, i=0.1, imax=50)

def find_max(blobs):
    max_size=0
    for blob in blobs:
        if blob[2]*blob[3] > max_size:
            max_blob=blob
            max_size = blob[2]*blob[3]
    return max_blob

while(True):
    clock.tick()
    img = sensor.snapshot()
    blobs = img.find_blobs([red_threshold])

    if blobs:
        max_blob = find_max(blobs)
        x_error = max_blob[5]-img.width()/2
        h_error = max_blob[2]*max_blob[3]-size_threshold
        print("x error: ", x_error)
        
        img.draw_rectangle(max_blob[0:4])
        img.draw_cross(max_blob[5], max_blob[6])
        x_output=x_pid.get_pid(x_error,1)
        h_output=h_pid.get_pid(h_error,1)
        print("h_output",h_output)
        car.run(10,-10)
        car.run(-h_output-x_output,-h_output+x_output)

    else:
       car.run(10,-10)

Ayisha

2

That car module is not something standard or built-in, it’s a module they wrote specifically for that tutorial. You can find the code for that tutorial here, however note that it’s from 2019 so it might not still work and you may need to make changes to make it work.

http://booken.openmv.cc/project/zhui-xiao-qiu-de-xiao-8f665d28-project-pan-tilt-md.html

3

Is there then a different way to control motors? I’m planning to use 2 servo motors that can connect to an arduino.

4

Yeah, see the servo_control examples in the IDE menu for the board you’re using. if you’re using the servo shield, that has its own chip and examples.