Hi.
I was reading this:
https://docs.modalai.com/voxl-datasheets-connectors/#j13-expansion-b2b-connection
and wanted to make sure I understood corrrectly:
There are 2 I2C ports/buses available on this connector (J13 - B2B) ?
If so, can one be used as an I2C master/host, and the other as a slave (for use with external master) ?

Also, I haven't seen any information about PWM outputs. Does the VOXL have any hardware PWM outputs? If so, on which pins?

Thanks.

We are having problems running multiple cameras over MPA. System image 0.9 (4.0).
We are running 2 UVC cameras via voxl-uvc-server and one TOF via voxl-camera server.

One UVC camera is a color, 640x480 @ 30fps frame. The other is a RAW16 of 160x120 @ 5fps.
The TOF is 224x172 @ 10 fps, gray image + depth.

When we try to run all three together, we start to get problems. Running each one alone works fine.
The problems are usually that the camera/uvc server either gets stuck (frames are not published to the pipe) or the server crashes.

It seems like there is some sort of throughput problem, where the MPA cannot handle these 4 pipes simultaneously.

Any suggestions?
Unfortunately we cannot change the FPS of the color camera, as the resolution and fps are native.

Just to add to this post: I had similar problems with platform image 3.8 (clean install + wipe).
Deleting the /data/network/files didn't help.

I noticed in the systemctl status docker-daemon that there is were various network related errors, probably in the absense of a valid internet connection (VOXL was configured as AP).
For example: Error getting v2 registry: Get https://registry-1.docker.io/v2/: x509: certificate has expired or is not yet valid" and "HTTP Error" err="No such image: hello-world:latest" statusCode=404.

After connecting the VOXL to a Wifi router with internet access and rebooting, it seems like the daemon is able to run on boot without issues.

Is this how its supposed to work? Can't a new VOXL install be successful without internet connection ?

Thanks

Thanks for the replies.

The use case is low-bandwidth, short range communication to the VOXL using low-energy devices, which only have BLE.

Hi.
Having that the VOXL has the QCNFA324 Wifi module, which AFAIK also supports Bluetooth, I was wondering if there is any support for this ?
What would be needed in order to enable usage of the Bluetooth on the VOXL ?

Thanks.

Any help about running 2 USB cameras ?
Can I just remove the code that limits this in UVC-server ?
Thanks

Hi.
I'm using voxl-uvc-server (v0.1.3) on system image v3.8.

I have experienced a few problems:

1. When two different cameras are attached via USB hub (either powered or unpowered) to debug board's USB, voxl-uvc-server usually fails at opening the device.
   If I boot with only one camera attached to the USB hub, it works on the first try. With two cameras attached, it fails (uvc_open failed) around two to three consecutive tries, until its successful.
   In this scenario I was only running one instance of voxl-uvc-server. No other software was accessing UVC (AFAIK) on the VOXL.

2. I'm trying to use voxl-uvc-server for both cameras. From the docs it should be possible, as they are different brand/type of cameras, and I'm giving each one a unique frame rate.
   
   But in practice, it doesn't work: The code for voxl-uvc-server prevents two instances from running simultaneously:

int main(int argc, char *argv[]) {

    ////////////////////////////////////////////////////////////////////////////////
    // gracefully handle an existing instance of the process and associated PID file
    ////////////////////////////////////////////////////////////////////////////////

    // make sure another instance isn't running
    // if return value is -3 then a background process is running with
    // higher privaledges and we couldn't kill it, in which case we should
    // not continue or there may be hardware conflicts. If it returned -4
    // then there was an invalid argument that needs to be fixed.
    if(kill_existing_process(SERVER_NAME, 2.0)<-2) return -1;

    // start signal handler so we can exit cleanly
    if(enable_signal_handler()==-1){
        fprintf(stderr,"ERROR: failed to start signal handler\n");
        return -1;
    }

    // make PID file to indicate your project is running
    // due to the check made on the call to rc_kill_existing_process() above
    // we can be fairly confident there is no PID file already and we can
    // make our own safely.
    make_pid_file(SERVER_NAME);

How can I run two instances on the VOXL ?

Thanks.

Hi.
Ever since we upgraded to platform image 0.9 (4.0 ?) we are experiencing unstable Wifi on the VOXL. It worked fine with system image 3.6 on the same device.

The Wifi is now unstable in both AP and Station modes. We especially experience problems when trying to SCP a ~300Mb file from the VOXL to a PC, on the same Wifi Network (or AP mode).
It starts downloading but then we loose the Wifi signal from the VOXL. It simply drops. Sometimes a reboot of the VOXL is required to regain connectivity.
This has been tested various times, using different PCs too.

Any ideas?
Seems like a bug in the new image (which we need due to some other improvements).
Thanks.

Hello.
I noticed that the /mnt/sdcard/ and /sdcard/ mounts exists even when the sdcard is not inserted into the VOXL.
This came up when the root mount (eMMC) got full for some odd reason. I then noticed that the sdcard on the VOXL had popped out and my docker was writing stuff to /sdcard. This filled up the eMMC. This situation is a bit dangerous, because while you think you are writing to the sdcard, in fact you are writing to the eMMC.

I would like to know if there is a way to disable these mounts if the sdcard isn't inserted or happened to pop out (the spring on the sdcard holder of the VOXL is kind of weak).

Thanks

Hi.
We have a few VOXLs and we've come by some intermittent Wifi connection issues, when working in "station" mode:
Sometimes the VOXL will connect just fine to the Wifi router (TP-Link Archer VR600), and sometimes it simply doesn't. Even after running voxl-wifi with the correct credentials several times, it doesn't always work. This has been tested on multiple VOXLs, all running system image 3.3.0. We have also tested this using different routers of the exact same model - same behaviour. Wifi antennas are in place of course, and 5Ghz wifi is disabled on the router (only using 2.4Ghz).

Rebooting the router doesn't help either. We do not have any problems connecting our laptops to the router, nor do we see this behaviour with other various SBCs (NanoPi/Raspberry Pi etc..). The VOXLs work fine in AP mode and we are able to connect to them separately, but its very inconvenient.

My question is:

1. Is this a known issue? If so, how do we work around it ?
2. Is there any way to "debug" wifi issues on the VOXL ? We haven't seen anything special on journalctl.

Thanks.

@Chad-Sweet
I'm trying to read some sensor data using UART/I2C, from within a Docker container.

I will look into libmodal_pipe , thanks.