making a digital dashboard using obd2 elm327 and pygame but screen is black when obd2 is put in the code the obd works on its own

Question

a friend and i are making a digital dashboard on a rasspberry pi but we keep running into problem when combining the obd code and the pygame. sepertaly they wwork but together it is either pygame or obd that doesn't work. origanaly we tried doing it by asking the data this way:

import obd
from  obd import OBDStatus
connection=obd.OBD("/dev/rfcomm0")
obd.logger.setLevel(obd.logging.DEBUG)

print (obd.OBD(fast=False , timeout =30,protocol = 0))
print(OBDStatus.ELM_CONNECTED)
print(OBDStatus.OBD_CONNECTED)
print(OBDStatus.CAR_CONNECTED)

cmd=obd.commands.SPEED 

response=connection.query(cmd)

print(response.value)

connection.close()

but we ran into problems with speed that the ignition was off. now we do it the watch command from obd and now obd part works but pygame stopped working because of it. we don't realy know is going wrong as we stopped getting error's in the debug screen

this is the combined code:

import pygame
from pygame.locals import *
import obd

pygame.init()

def rotate(surface, angle, pivot, offset):
    rotated_image = pygame.transform.rotozoom(surface, -angle, 1)  
    rotated_offset = offset.rotate(angle)  
    
    rect = rotated_image.get_rect(center=pivot+rotated_offset)
    return rotated_image, rect

def get_speed(s):
    global speed
    if not s.is_null():
        speed = int(s.value.magnitude) #for kph
        print(speed)
def get_rpm(r):
    global rpm
    if not r.is_null():
        rpm = int(r.value.magnitude)
        print(rpm)
def get_load(l):
    global load
    if not l.is_null():
        load = int(l.value.magnitude)

def angle_up(angle):
    angle += 1
    return angle

def angle_down(angle):
   angle -= 1
   return angle

connection = obd.Async(fast=False)

connection.watch(obd.commands.SPEED, callback=get_speed)
connection.watch(obd.commands.RPM, callback=get_rpm)
connection.watch(obd.commands.ENGINE_LOAD, callback=get_load)
connection.start()

hoek1 = -225
hoek2 = -225
hoek3 = -226

speed = 0
rpm = 0
load = 0

SCREEN_WIDTH = 1920
SCREEN_HEIGHT = 1080

offset = pygame.math.Vector2(162.5, 0)

center1 = int(SCREEN_WIDTH/5), int(SCREEN_HEIGHT/2)
center2 = int(SCREEN_WIDTH*(3/5)), int(SCREEN_HEIGHT/2)
center3 = SCREEN_WIDTH, int(SCREEN_HEIGHT/2)

screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))

clock = pygame.time.Clock()

running = True

Background = pygame.image.load('./graphics/Background.png').convert_alpha()

surf1 = pygame.image.load('./graphics/Wijzer.png').convert_alpha()
surf2 = pygame.image.load('./graphics/Wijzer.png').convert_alpha()
surf3 = pygame.image.load('./graphics/Wijzer.png').convert_alpha()

UPDATE =pygame.USEREVENT + 1
pygame.time.set_timer(UPDATE, 250)

while running:
    for event in pygame.event.get():
        if event.type == KEYDOWN:
            if event.key == K_ESCAPE:
                connection.stop()
                running = False
        elif event.type == QUIT:
            connection.stop()
            running = False
        elif event.type == UPDATE:
            if speed > hoek1:
                hoek1 = angle_up(hoek1)
            if speed < hoek1:
                hoek1 = angle_down(hoek1)
            if rpm > hoek2:
                hoek2 = angle_up(hoek2)
            if rpm < hoek2:
                hoek2 = angle_down(hoek2)
            if load > hoek3:
                hoek3 = angle_up(hoek3)
            if load < hoek3:
                hoek3 = angle_down(hoek3)

    if hoek1 > 45:
        hoek1 = 45
    if hoek2 > 45:
        hoek2 = 45
    if hoek3 > -135:
        hoek3 = -135
        
    if hoek1 < -225:
        hoek1 = -225
    if hoek2 < -225:
        hoek2 = -225
    if hoek3 < -225:
        hoek3 = -225

    surf1_rotated, surf_center1_rotated = rotate(surf1, hoek1, center1, offset)
    surf2_rotated, surf_center2_rotated = rotate(surf2, hoek2, center2, offset)
    surf3_rotated, surf_center3_rotated = rotate(surf3, hoek3, center3, offset)

    screen.blit(Background, (0,0))

    screen.blit(surf1_rotated, surf_center1_rotated)
    screen.blit(surf2_rotated, surf_center2_rotated)
    screen.blit(surf3_rotated, surf_center3_rotated)
    pygame.display.flip()

    clock.tick(30)
pygame.quit()

the code is on this github link: https://github.com/EGO-mercenary/Dashboard