# Stereo Image sensor selection Source: https://forum.modalai.com/topic/4262/stereo-image-sensor-selection Category: VOXL SDK and Software (https://forum.modalai.com/category/47/voxl-sdk-and-software) Tags: camera Posted: 2025-03-17 17:11:50 UTC by SKA Replies: 6 · Views: 1770 ## SKA · 2025-03-17 17:11:50 UTC @Alex-Kushleyev We have been advised that the ov sensor modules for dfs are approaching end of life. Which camera options do you recommend we consider instead? Thank you for your help! ## Reply by Alex Kushleyev (ModalAI staff) · 2025-03-18 02:11:06 UTC Hello @SKA, The replacement for OV7251 in DFS use case (Depth From Stereo) will be AR0144 which is a 1280x800 resolution global shutter sensor, compared to 640x480 OV7251. The AR0144 camera is already available and we use for VIO (tracking) cameras. You would probably want to use the micro-coax version of AR0144 (M0166) because it will be much more flexible in terms of getting the wiring connected to VOXL2 (so M0166 + M0173 (Starling Camera Front End). Different cable lengths are available to support different base lines. Take a look at some camera bundle options : https://docs.modalai.com/voxl2-coax-camera-bundles/ We are working on testing this configuration of dual AR0144 in DFS application and updating the DFS server to optimize performance. I expect to have an update in the next 1-2 weeks regarding the DFS performance. Alex ## Reply by SKA · 2025-08-21 18:58:38 UTC (in reply to Alex Kushleyev) Hi @Alex-Kushleyev! I am trying to get my stereo AR0144 cam setup working. I originally had AR0144 stereo+DFS working with the flex sensor cameras, but after shifting to M0188 + microcoax cameras I haven't been able to accomplish the same. Currently I have 2 AR0144 microcoax cams connected to port J0 and J6 of the M0188 board. When I configure the cameras and run ```voxl-camera-server```, I see two separate video outputs from stereo (1280x800) and stereo_child (1280x800) respectively. Then, when I go into ```voxl-camera-server.conf``` and adjust it to stereo mode by adding camera_second_id, I see the new stereo output (1280x1600) but video is either empty or all dark. I have all the necessary intrinsics and extrinsics files that worked previously with the flex connector cameras. Let me know if I'm missing anything, and how I can try to get this working. Thanks! I'm using voxl-camera-server version: 2.2.6-202508142059 Here's the output when I run ```voxl-camera-server```: ``` Setting MISP AWB to Auto MISP channels enabled in defaults : 0 MISP channels enabled in config file: 0 ================================================================= configuration for 1 cameras: cam #0 name: stereo type: ar0144 bayer_type: 0 enabled: 1 camera_id: 0 camera_id_second: 2 fps: 30 en_rotate: 0 en_rotate2: 0 en_preview: 1 en_raw_preview: 1 preview_width: 1280 preview_height: 800 en_misp: 1 misp_width: 1280 misp_height: 800 en_small_video: 0 small_video_width: -1 small_video_height: -1 en_large_video: 0 large_video_width: -1 large_video_height: -1 en_snapshot: 0 snap_width: -1 snap_height: -1 exif_focal_length: 0.000000 exif_focal_len_35mm_format:0 exif_fnumber: 0.000000 ae_mode: lme_msv msv_exposure_min_us: 20 msv_exposure_max_us: 12000 gain_min : 54 gain_max : 8000 standby_enabled: 0 decimator: 1 independent_exposure:0 fsync_en: 1 fsync_gpio: 109 ================================================================= thread is locked to cores: 4 5 6 7 connected to mavlink pipe Connected to cpu-monitor Starting Camera: stereo (id #0) Opened GBM fd gbm_create_device(156): Info: backend name is: msm_drm Created GBM device MISP Initializing for camera stereo Detected 1 platform(s) Detected 1 GPU device(s) Estimated imu dt = 0.000978s Got unsupported format in getUVStartFromFmt, returning nullptr WARNING: OMX SetTargetBitrate: H265 CBR requires bps >= 3.0Mbit (2000000 bps provided). Using FPS hack. scale = 1.500000 Loading intrinsics cal file stereo_intrinsics.yml for camera stereo, ret 0 stereo lens calibration (fisheye): w: 1280, h:800 fx: 563.677, fy: 562.169 cx: 663.707, cy: 390.645 D: -0.062035, 0.065024, -0.041547, 0.008022, 0.000000 Loading extrinsics for camera stereo, ret 0 Extrinsics: 0.0000 1.0000 0.0000 -0.0000 0.0000 1.0000 1.0000 -0.0000 0.0000 Loading EIS output extrinsics for camera stereo, fetch ret 0 EIS Extrinsics: 1.0000 -0.0000 0.0000 0.0000 1.0000 -0.0000 0.0000 0.0000 1.0000 MISP Initializing for camera stereo_child Got unsupported format in getUVStartFromFmt, returning nullptr WARNING: OMX SetTargetBitrate: H265 CBR requires bps >= 3.0Mbit (2000000 bps provided). Using FPS hack. scale = 1.500000 Loading intrinsics cal file stereo_child_intrinsics.yml for camera stereo_child, ret 0 stereo_child lens calibration (fisheye): w: 1280, h:800 fx: 563.677, fy: 562.169 cx: 663.707, cy: 390.645 D: -0.062035, 0.065024, -0.041547, 0.008022, 0.000000 Loading extrinsics for camera stereo_child, ret 0 Extrinsics: 0.0000 -1.0000 0.0000 0.0000 0.0000 1.0000 -1.0000 -0.0000 0.0000 Loading EIS output extrinsics for camera stereo_child, fetch ret 0 EIS Extrinsics: 1.0000 -0.0000 0.0000 0.0000 1.0000 -0.0000 0.0000 0.0000 1.0000 ------ voxl-camera-server: Started 1 of 1 cameras ------ voxl-camera-server: Camera server is now running ``` ## Reply by Alex Kushleyev (ModalAI staff) · 2025-08-22 00:59:17 UTC (in reply to SKA) @SKA , how many cameras do you have connected? Also, what does “voxl-camera-server -l” show and what sensormodules do you have in /usr/lib/camera? Alex ## Reply by SKA · 2025-08-22 01:53:59 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev I have 3 cameras connected in total. The earlier camera server output was for just the stereo pair. Cam ID 0 connected at port J0 - AR0144 Cam ID 1 connected at port J1 - IMX412 Cam ID 2 connected at port J6 - AR0144 I have experimented with using all of the ar0144 combo drivers, currently I have ```com.qti.sensormodule.ar0144_fsin_combo_0``` and ```com.qti.sensormodule.ar0144_fsin_combo_6```. Using these drivers, the video streams appear normal when voxl-camera-server is configured to have the 2 AR0144 cameras stream separately instead of as a stereo pair. When I run ```voxl-camera-server -l```, it recognizes 3 cameras connected. I'll update with the exact output soon. ## Reply by Alex Kushleyev (ModalAI staff) · 2025-08-22 03:07:04 UTC (in reply to SKA) @SKA , If you would like to get the joined stereo image, i believe you need to disable MISP. currently you have `en_misp` set to true. Please set it to false and try again. MISP is not set up to work with joining two images into one. Disabling MISP will default to the original behavior that you are expecting. I should add a warning about this, when MISP is enabled. Thank you. Please let me know if disabling MISP works for you. Alex ## Reply by SKA · 2025-08-25 02:50:00 UTC (in reply to Alex Kushleyev) @Alex-Kushleyev This worked! Thank you