Auto Exposure setting test for See3CAM CU20

see3cam_cu20_ae_setting_test.py

import os
from pyudev import Context
import errno
import sys
from select import select
from time import sleep

# Based on below code
# https://github.com/econsysqtcam/qtcam/blob/6b9d31bb7fa9ecf619987cc1433c1ac2398706fe/src/see3cam_cu20.cpp

BUFFER_LENGTH = 65
READ_FIRMWARE_VERSION = 0x40
CAMERA_CONTROL_CU20 = 0x86
SET_AE_ROI_MODE_CU20 = 0x06
GET_AE_ROI_MODE_CU20 = 0x05
GET_DENOISE_MODE_CU20 = 0x15

AutoExpCentered = 0x01
AutoExpManual = 0x02
AutoExpDisabled = 0x03

# Based on below code
# https://github.com/econsystems/opencv/blob/master/Source/PythonScript/hid.py

def hid_write(hid_handle, input_buffer):
    if input_buffer is not None:
        retry_count = 0
        bytes_written = 0
        while retry_count < 3:
            try:
                bytes_written = os.write(hid_handle, input_buffer)
                retry_count += 1
            except IOError as e:
                if e.errno == errno.EPIPE:
                    sleep(0.1)
            else:
                break
        if bytes_written != len(input_buffer):
            raise IOError(errno.EIO, 'Written %d bytes out of expected %d' % (bytes_written, len(input_buffer)))
    return True

def hid_read(hid_handle, BUFFER_LENGTH):
    output_buffer = None
    timeout = 2000.0
    rlist, wlist, xlist = select([hid_handle], [], [hid_handle], timeout)

    if xlist:
        if xlist == [hid_handle]:
            raise IOError(errno.EIO, 'exception on file descriptor %d' % hid_handle)

    if rlist:
        if rlist == [hid_handle]:
            output_buffer = os.read(hid_handle, BUFFER_LENGTH)
            if output_buffer is None:
                return b''
    return output_buffer

# Get CU20 hid_handler 
device_count = 0
for device in Context().list_devices(subsystem='hidraw'):
    usb_device = device.find_parent('usb', 'usb_device')
    if usb_device:
        vendor_id = usb_device.get('ID_VENDOR_ID')
        product_id = usb_device.get('ID_MODEL_ID')
        if vendor_id == '2560' and product_id == 'c120':
            hid_device_path = device.device_node

hid_handle = os.open(hid_device_path, os.O_RDWR, os.O_NONBLOCK)

# Get Firmware info
input_buffer = bytearray([0] * BUFFER_LENGTH)
input_buffer[0] = 0x00
input_buffer[1] = READ_FIRMWARE_VERSION
hid_write(hid_handle, input_buffer)
output_buffer = hid_read(hid_handle, BUFFER_LENGTH=BUFFER_LENGTH)
if output_buffer[0] != READ_FIRMWARE_VERSION:
    print("Wrong Information is detected")

SDK_VER = (output_buffer[3] << 8) + output_buffer[4]
SVN_VER = (output_buffer[5] << 8) + output_buffer[6]
pMajorVersion = output_buffer[1]
pMinorVersion1 = output_buffer[2]
print(f"Firmware Version is {pMajorVersion}.{pMinorVersion1}.{SDK_VER}.{SVN_VER}")

# Try to set autoexposure setting
input_buffer = bytearray([0] * BUFFER_LENGTH)
input_buffer[0] = CAMERA_CONTROL_CU20
input_buffer[1] = SET_AE_ROI_MODE_CU20
input_buffer[2] = AutoExpCentered
hid_write(hid_handle, input_buffer)
output_buffer = hid_read(hid_handle, BUFFER_LENGTH=BUFFER_LENGTH)
print(output_buffer)

input_buffer = bytearray([0] * BUFFER_LENGTH)
input_buffer[0] = CAMERA_CONTROL_CU20
input_buffer[1] = GET_AE_ROI_MODE_CU20
hid_write(hid_handle, input_buffer)
output_buffer = hid_read(hid_handle, BUFFER_LENGTH=BUFFER_LENGTH)
print(output_buffer)

By rewriting line 89-112 like as below, it is seems to work.

# Try to set autoexposure setting
input_buffer = bytearray([0] * BUFFER_LENGTH)
input_buffer[1] = CAMERA_CONTROL_CU20
input_buffer[2] = SET_AE_ROI_MODE_CU20
input_buffer[3] = AutoExpCentered
hid_write(hid_handle, input_buffer)
output_buffer = hid_read(hid_handle, BUFFER_LENGTH=BUFFER_LENGTH)
if output_buffer[6] == 0x00:
    print("\nSet AE Failed")
elif output_buffer[0] == CAMERA_CONTROL_CU20 and output_buffer[1] == SET_AE_ROI_MODE_CU20 and output_buffer[6] == SUCCESS:
    print("\nSet AE ROI Success")


input_buffer = bytearray([0] * BUFFER_LENGTH)
input_buffer[1] = CAMERA_CONTROL_CU20
input_buffer[2] = GET_AE_ROI_MODE_CU20
hid_write(hid_handle, input_buffer)
output_buffer = hid_read(hid_handle, BUFFER_LENGTH=BUFFER_LENGTH)
if output_buffer[6] == 0x00:
    print("\nGet AE ROI Failed")
elif output_buffer[0] == CAMERA_CONTROL_CU20 and output_buffer[1] == GET_AE_ROI_MODE_CU20 and output_buffer[6] == SUCCESS:
    print("\nGet AE ROI Success")
    print("RoI Mode (1-Auto/2-Manual): {}".format(output_buffer[2]))
    print("Window Size Setting (valid only in manual mode): {}".format(output_buffer[5]))

Firmware Version is 1.10.131.1692

Set AE ROI Success

Get AE ROI Success
RoI Mode (1-Auto/2-Manual): 1
Window Size Setting (valid only in manual mode): 0