Capture image with Arducam OV5642 + Rpi Pico + SD Card Module + Trigger using CircuitPython

arducam_capture_pico_sdcard_with_trigger.py

import time as utime
import busio
import board
import usb_cdc
from Arducam import *
from board import *
import os

import sdcardio
import storage

from digitalio import DigitalInOut, Direction, Pull

trigger = DigitalInOut(GP14)
trigger.direction = Direction.INPUT
trigger.pull = Pull.UP

path = '/sd/'
filename = 'test'
extension = '.jpg'

def get_filename():
    return path + filename + str(imageCounter) + extension

imageCounter = 0
mode = 0
start_capture = 0
stop_flag=0
once_number=128
value_command=0
flag_command=0
buffer=bytearray(once_number)
isCapturing = False

spi = busio.SPI(GP10, MOSI=GP11, MISO=GP12)
cs = GP13
sd = sdcardio.SDCard(spi, cs)

vfs = storage.VfsFat(sd)
storage.mount(vfs, '/sd')
with open(get_filename(), 'wb'):
    pass

mycam = ArducamClass(OV5642)
mycam.Camera_Detection()
mycam.Spi_Test()
mycam.Camera_Init()
utime.sleep(1)
mycam.set_format(JPEG)
mycam.OV5642_set_JPEG_size(OV5642_1280x960)
        
def get_still(mycam):
    once_number = 128
    buffer=bytearray(once_number)
    count = 0
    finished = 0
    length = mycam.read_fifo_length()
    mycam.SPI_CS_LOW()
    mycam.set_fifo_burst()

    while finished == 0:
        mycam.spi.readinto(buffer, start=0, end=once_number)
        print(str(count) + ' of ' + str(length))
        with open(get_filename(), 'ab') as fj:
            fj.write(buffer)
        count += once_number
        
        if count + once_number > length:
            print(str(count) + ' of ' + str(length))
            count = length - count
            mycam.spi.readinto(buffer, start=0, end=count)
            with open(get_filename(), 'ab') as fj:
                fj.write(buffer)
            mycam.SPI_CS_HIGH()
            mycam.clear_fifo_flag()
            finished = 1
            return finished

def capture_image():
    mycam.flush_fifo()
    mycam.clear_fifo_flag()
    mycam.start_capture()
    finished = 0
    while finished == 0:
        if mycam.get_bit(ARDUCHIP_TRIG,CAP_DONE_MASK)!=0:
            finished = get_still(mycam)
    print('Capture Finished!')
    print(get_filename())

while True:
    if not trigger.value:
        print("Triggered")
        if not isCapturing:
            isCapturing = True
            capture_image();
            imageCounter = imageCounter + 1
    else:
        isCapturing = False
        pass

    utime.sleep(0.1)

Really useful - thank you so much for making this code available! I was wondering if you knew of a way to open the image saved on the sd and hold it as pixel values of shape (height,width,3) in a ulab.numpy array?

@shepai I don't have the code but maybe you could use the Pillow Library for doing that.

Thank you very much for the code for reference, I experimented around with it a bit and found that increasing the once_number value (which I understand is the buffer size?) helps in reducing the time taken for the picture to finish taken and saved on sd card, is there a reason why its not set higher by default, and what does this buffer size thing really means?

It is unfortunate that it took so long to take a single picture as I had assumed it is viable to use this hardware for video related project but this proven to be wrong after delving more into the hardware (OV5642) and github issues on related codebase including Arduino one as I recently posted in my own issue post ArduCAM/PICO_SPI_CAM#14. In this regard, have u done any testing regarding the hardware video capabilities especially when used together with Raspberry Pi Pico (RP2040). Thanks again.

Best regards,
Muhammad

Hi Muhammad!

what does this buffer size thing really means?

This was picked from another script I found but did not experiment with it any further because I had so many issues making it work.

have u done any testing regarding the hardware video

No, I was only looking to take pictures. It's possible to record a video but I cannot help you with that.

Unfortunately, Arducam did not put any effort into making the software accessible to all consumers. They only focus on hardware, and that is an error. I'm sorry I can't help you. I hope you have better luck than me with contacting Arducam because they usually don't answer any questions on their GitHub repositories. 😞