OG0VA1B External Trigger

External Trigger Signal

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Pinout Definition

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Name	Pin
trigger input	XVS
ground	GND

Windows GUI

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Arducam USB Camera Shield GUI

Access Camera Kit

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Tip

The new version of OG0VA1B Evaluation Kit supports external trigger function. If you need related application, please contact sales@arducam.com for the configuration file.

External Trigger Python code

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This tutorial is based on Raspberry Pi. You can use any embedded device that supports signal transmission in practice. Please correctly connect the camera and trigger signal parts according to the hardware connection section.

import RPi.GPIO as GPIO
import time
import argparse

GPIO.setwarnings(False)
GPIO.cleanup()
GPIO.setmode(GPIO.BCM)

GPIO.setup(18,GPIO.OUT)

def main(framerate, trigger_time):
    trigger_time = trigger_time / 1000
    sleep_time = 1/framerate
    sleep_time = round(sleep_time, 3) - trigger_time
    print("Start Trigger! Press CTRL+C to exit")
    try:
        while 1:
            GPIO.output(18, GPIO.HIGH)
            time.sleep(trigger_time)
            GPIO.output(18, GPIO.LOW)
            time.sleep(sleep_time)

    except KeyboardInterrupt:
        GPIO.cleanup()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Trigger")
    parser.add_argument("-f", "--framerate", type=float, default=30, help="frame rate")
    parser.add_argument("-t", "--trigger-time", type=float, default=1, help="Trigger signal maintains high level time (ms)")
    args = parser.parse_args()

    main(args.framerate, args.trigger_time)

-f: frame rate of external trigger, in this example the trigger is 140 frames

python3 trigger.py -f 140

Demonstration

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Due to the default exposure time is relatively long, if you want to get a higher frame rate, you need to reduce the exposure time. For example, if you need to trigger externally to 140 frames, you need to adjust the exposure time to about 600 us.

Note

If the frame rate does not reach the desired frame rate, you can try to reduce the exposure time.