Working with multiple STEVAL-EVK-U0I boards

[oaa3wf]

Hi, 

I'm curious to see if it is possible to connect more than one STEVAL-EVK-U0I boards to a computer and read images of all of them? The SDK has  an init function that allows you give a board id, but it is unclear what the board id means or if it will give the desired effect. Any help is appreciated. 

Thanks

[Jean_Poire · Accepted solution]

Hi @oaa3wf ,

It is indeed possible to use simultaneously more than one STEVAL-EVK-U0I boards. An id (starting from 0) is automatically attributed when more than one board is detected. You just have to define two sensor_dll object in the python script:

# # Init the board
first_sensor_dll = SensorDll(LIB_NAME, decode_frame)
first_sensor_dll.init_board(board_id=0)
second_sensor_dll = SensorDll(LIB_NAME, decode_frame)
second_sensor_dll.init_board(board_id=1)

 Best regards,

Jean

[oaa3wf]

Thanks @Jean_Poire . I'll give it a try.

[oaa3wf]

So I gave this a try and got the following:

Loading st_brightsense_sdk_vdx6gx.dll
IMG platform version 305 loaded :)
Boards connected: (0,P4405C-00A#0306) (1,P4405C-00A#0310)
Board ID selected : 0
Initiating CCI communication at address 32
Sensor detected on interface 0
Loading st_brightsense_sdk_vdx6gx.dll
IMG platform version 305 loaded :)
Boards connected: (0,P4405C-00A#0306) (1,P4405C-00A#0310)
Board ID selected : 1
Initiating CCI communication at address 32
Sensor detected on interface 0
IMG_PLAT error (1): Error: Wait8, could not reach value 0 for register 513 last read: 1;(Failed to acknowledge command)

Still debugging, but going to but it up here in case someone has run into this before.

[Jean_Poire]

That is already a good progress as the two boards are well detected!

If you need further assistance for debugging, please provide your script so I can check it on my side.  

Best Regards,

Jean

[oaa3wf]

Thanks @Jean_Poire , unfortunately, I wasn't able to figure out the issue. I notice that LED D6 goes red for a second when the problem occurs. I think it should be reproducible with the code below (and the SDK):

import os

from vdx6gx_constants import *
from vdx6gx_frame_decoding import decode_frame
from image_sensor_python_sdk import *
from smart_imshow import SmartImshow
import threading
import time

bits_per_pixel = BITS_8

x_start = 2
x_end = 1105
y_start = 2
y_end = 1361

# height = 640
# width = 480

# x_end = x_start + width - 1
# y_end = y_start + height - 1
width = x_end - x_start + 1
height = y_end - y_start + 1

data_rate_mbps = 1500

def getSensorDll(i2c_address: int = 32, boardId: int = 0):
    # Init the board
    sensor_dll = SensorDll(LIB_NAME, decode_frame)
    sensor_dll.init_board(i2c_address, board_id=boardId)
    sensor_dll.Write16(VDx6Gx_REG_STATICS_FORMAT_CTRL, bits_per_pixel)
    # Slave mode
    slave_mode = 2

    # Set the sensor configuration (VD55G1 specific)

    sensor_dll.Write16(VDx6Gx_REG_STATUS_FRAME_RATE, 30)
    sensor_dll.Write8(VDx6Gx_REG_STREAM_STATICS_ORIENTATION, 0)
    sensor_dll.Write16(VDx6Gx_REG_STREAM_CTX0_FRAME_LENGTH,4200)


    sensor_dll.Write16(VDx6Gx_REG_CONTEXTS_OUT_ROI_X_START, x_start)
    sensor_dll.Write16(VDx6Gx_REG_CONTEXTS_OUT_ROI_X_END, x_end)
    sensor_dll.Write16(VDx6Gx_REG_CONTEXTS_OUT_ROI_Y_START, y_start)
    sensor_dll.Write16(VDx6Gx_REG_CONTEXTS_OUT_ROI_Y_END, y_end)

    sensor_dll.reconfigure_csi_receiver(2, data_rate_mbps, 1116, 1356, bits_per_pixel, 160800000)
    # sensor_dll.reconfigure_csi_receiver(2, data_rate_mbps, 480, 642, bits_per_pixel, 160800000)
    sensor_dll.Write8(VDx6Gx_REG_STATUS_VT_CTRL, slave_mode)

    return sensor_dll




sensor_dll_0 = getSensorDll(32, 0)
sensor_dll_1 = getSensorDll(32, 1)
print("----------------------------------- done setting up", flush=True)

print("----------------------------------- starting streams", flush=True)
time.sleep(5.0)
sensor_dll_0.start_stream()
print("------started stream 0")
time.sleep(5.0)
sensor_dll_1.start_stream()
print("------started stream 1")

# sleep for 10 seconds and shutdown
time.sleep(10.0)

sensor_dll_0.stop_stream()
sensor_dll_1.stop_stream()
sensor_dll_0.deinit_board()
sensor_dll_1.deinit_board()

Thanks 

[Jean_Poire]

Hi @oaa3wf ,

There is indeed a small issue with the management of the dll. As you are trying to stream with 2 vdx6gx you are using the same dll. When you are initializing your second board you are overwriting the sensor_dll object and now both sensor_dll_0 and sensor_dll_1 are talking to the same board. That is why the second start_stream() raise an error as the sensor is already streaming. A workaround is to create a copy of the dll and make two call to two different dll: 

In my folder I have now 4 files :

st_brightsense_sdk_vdx6gx_0.dll

st_brightsense_sdk_vdx6gx_0.h

st_brightsense_sdk_vdx6gx_1.dll

st_brightsense_sdk_vdx6gx_1.h

Inside vdx6gx_constants.py:

SENSOR_DLL_NAME_0 = "st_brightsense_sdk_vdx6gx_0"
SENSOR_DLL_NAME_1 = "st_brightsense_sdk_vdx6gx_1"
LIB_NAME_0 = get_lib_name(SENSOR_DLL_NAME_0)
LIB_NAME_1 = get_lib_name(SENSOR_DLL_NAME_1)

Inside your script:

sensor_dll = SensorDll([LIB_NAME_0, LIB_NAME_1][boardId], decode_frame)

 I was able to make it work on my side using this workaround. I will search for the root cause and better solution when I have the bandwidth.

Sorry for the troubles,

Best regards,

Jean

[oaa3wf]

Thanks @Jean_Poire , your suggestion works!!