def picamera_logging_thread():
    logger.info('Started camera logging thread')
    while time() < start_time + timeout:
        with PiCamera() as camera:
            # set values
            camera.resolution = (3280, 2464)

            # let automatic exposure settle
            sleep(2)
            image_name = 'image_' + str(int(time()))

            # capture in PNG format at native resolution
            camera.capture(os.path.join(image_dir, image_name + '.png'))
            logger.info('Saved image ' + image_name + '.png')

            # let automatic exposure settle
            sleep(2)
            image_name = 'image_' + str(int(time()))

            # capture in unencoded RGB format
            camera.capture(os.path.join(image_dir, image_name + '.data'), 'rgb')
            logger.info('Saved image ' + image_name + '.data')

        # delay the specified interval
        sleep(picamera_logging_interval - 4)
    logger.info('Stopped camera logging thread')

start_time = time()

# start logging threads
Thread(target = sensehat_logging_thread).start()
Thread(target = picamera_logging_thread).start()