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  • Note sure where to post? Ask questions here for direct access to the ModalAI engineering team

    Support Request Format for Best Results Feature Requests 3D Models
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    Steven GonciarS

    For visibility, since this seems related to the old BLE/VOXL discussion here:
    https://forum.modalai.com/topic/1730/bluetooth-ble-communication-on-the-voxl-is-it-possible

    I was able to get BLE 5.0 extended advertising scanning working on VOXL2 / Starling 2 with an ASUS BT500 / Realtek RTL8761B USB adapter by backporting newer upstream Linux Bluetooth HCI event parsing logic into the QRB5165 4.19 kernel tree. My understanding is newer VOXL2 versions will have more up to date kernels that solve this issue.

    The issue we were hitting was with LE Extended Advertising Reports. With BLE 5.0 beacons transmitting extended advertising, the older 4.19 Bluetooth path could mis-handle extended advertising report parsing / event-type bits, leading to bad report handling and, in our case, Bluetooth instability / crashes during scanning.

    The relevant upstream Linux changes I used as reference include:

    b48b833f9e8a - Bluetooth: HCI: Use skb_pull_data to parse LE Ext Advertising Report event ad38e55e1c89 - Bluetooth: hci_event: Ignore reserved bits in LE Extended Adv Report 0cadf8534f2a - Bluetooth: hci_event: Mask data status from LE ext adv reports

    There are also related Realtek / extended-scan quirk changes upstream, but for our immediate case the stronger LE extended advertising parser backport was enough to stop the crash path and allow scanning.

    Validated result:

    VOXL2 / Starling 2 QRB5165 4.19 kernel ASUS BT500 / RTL8761B USB BLE adapter BLE 5.0 beacons using extended advertising btmgmt --index 0 find -l successfully reports devices and RSSI btmon captures LE Extended Advertising Report events no more Bluetooth NULL pointer dereference / hci_le_ext_adv_report_evt crash during the test observed all 16 expected beacons and repeated RSSI samples

    I’m not proposing this as a merge-ready ModalAI patch, but I put the build changes and notes here in case anyone else needs BLE 5.0 extended advertising / RSSI collection on VOXL2:

    https://gitlab.com/steven323/qrb5165-kernel-build-docker

    Relevant upstream commit links:
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b48b833f9e8a
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad38e55e1c89
    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0cadf8534f2a

  • Commonly asked questions we get from the community

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    297
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    Eric KatzfeyE

    @JB1 Our voxl-remote-id software with WiFi dongle is intended only for reference and is not meant to be a commercially ready system for our customers who need a remote id solution for their VOXL2 based drone products. Integration, testing, validation, and FAA registration with desired hardware is up to the end user. At a minimum the manufacturer id would need to be changed from ModalAI's id to your companies issued manufacturer id.

  • Questions by Product

    2199
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    11536
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    Timothy ZinwotaT

    @Alex-Kushleyev said in Starling 2 Max C28 vs C29:

    @jbiscan21 , yes you can add the TOF sensor to Starling 2 Max, but you will also need a new front plastic mount that will hold the hires and tracking cameras as well as the new TOF sensor.

    You can order the mount (which will be a drop in replacement for the original camera mount) with the TOF sensor. If you do want to proceed with the TOF sensor + plastics order, we will need to double check that all the necessary screws are included. You would need to send an email for a custom order to start this off and mention this thread and that we need to include mounting hardware. https://www.modalai.com/pages/contact-us

    (related post : https://forum.modalai.com/topic/5157/c29-configuration)

    See more detailed pictures.

    06f55cf3-051e-4cf8-8029-dc558eddf484-image.png

    d6b9c715-eb34-4012-8785-f8c317d4e743-image.png

    74789adc-815b-4c67-9663-aae23dc96106-image.png

    Alex

    @Alex-Kushleyev We are trying to purchase the TOF sensor for our Starling 2 max c28 configuration. The sales department asked to make a post on the forum for technical information which I did here

    Can you confirm if we can also reference this post to make the purchase for our drone with the required parts included? We'd like to place an order as soon as possible.

    Thank you,

    Timothy Zinwota
    University of Nevada, Las Vegas.

  • 499
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    2456
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    R

    @Eric-Katzfey thanks. before I did sdk reflash I found out the px4 params were somehow corrupted. I have tried to reproduce these values without success.
    what made it work is taking a similar drawn read the params usign px4-param show -a and writing the to the corrupted one.

  • Please request review from ModalAI before building your drone or custom add-on PCB

    PCB Design Reviews System Architecture Design Reviews
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    Posts

    Alex KushleyevA

    Hi @Eyal ,

    I just did a quick test and I am getting 2.0ms ping time when voxl2 cpu is in perf mode, and about 2.5ms when in auto mode. VOXL2 is idle.

    the NCM networking feature works concurrently with ADB, which is great and we also have some scripts to set up NAT if you need your voxl2 to actually use the Linux host as a "router" to access outside world. that is easy to set up as well (requires some routing changes on the linux host).

    In terms of real-time streaming, it is definitely adequate for image / video streaming to a Linux host. In fact, this option is my personal favorite way of connecting to Voxl2 while developing / testing cameras and viewing multiple streams in voxl-portal. Voxl-portal uses jpeg compression, which is a lot less efficient than h264/h265 and with the NCM connection, i don't have any issues (compared to adb port forwarding, which also allows voxl-portal to work, but is about 10x slower and uses a lot more CPU, you get frame drops in voxl-portal if required bandwidth is higher than 30-50Mbps or so). I am mainly using the USB-NCM feature for development purposes (as opposed to on a flying drone), but i have not found any limitations, at least for the bench testing use case.

    In terms of CPU load affecting the speed, i just ran a test stress -c 8 which loads up all 8 cores to 100% and the ping times did not change in perf mode (2.0ms) and in auto mode, the ping times reduced from 2.5ms to 2.0ms because the cpu cores are actually running at faster speeds. I am guessing that all the USB stuff is happening in the kernel at a higher priority, so it's not affected by the user applications (unless the cpu overheats, i supposed). GPU / DSP loads should not have any effect on this, since they are separate hardware.

    I also did another test - stream 4 video streams to voxl-portal (live view), which added up to about 100Mbps of network traffic and ping time stayed between 1.5-3.0ms (sometimes lower than 2.0ms).

    I have not observed any stability issues related to NCM being active for long periods of time (days). Make sure you are using a high quality USB-C cable (nothing fancy).

    Alex