Can also try exactly the same test, but with a standard PC / laptop and the same OS, to isolate the rPi/host hardware parameter
On Mon, Jun 25, 2018 at 7:30 AM Ian Buckley via USRP-users < usrp-users@lists.ettus.com> wrote: > Perhaps try 'sudo lsusb -v' with and without the LTE modem plugged in and > see if that reveals any more clues? > Does uhd_usrp_probe work when the LTE modem is plugged in? > > > On Jun 24, 2018, at 7:14 PM, Marcus D. Leech via USRP-users < > usrp-users@lists.ettus.com> wrote: > > On 06/24/2018 10:08 PM, GhostOp14 wrote: > > Hi Marcus, tried that too. No luck. Powered the USRP separately, then > tried powering the LTE separately. Same result. It's as if it can't read > block data on the USB bus when the LTE is connected. There's no data going > through the LTE so I'm not sure how that's possible. Especially since it > works fine as soon as I pull the LTE adapter out. > > Well, I'm going to go with "it's the LTE adapter". > > > > On Sun, Jun 24, 2018 at 5:24 PM, Marcus D. Leech via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> On 06/24/2018 04:25 PM, GhostOp14 via USRP-users wrote: >> >>> Hi folks, >>> >>> I have a weird issue I've been attempting to troubleshoot for a bit and >>> I'm stuck. >>> >>> So setup: >>> USRP B205 connected to a Raspberry Pi 3 (so USB 2 mode) >>> Huawei E3372 USB LTE adapter connected as well >>> Running the latest Raspbian (stretch) >>> >>> Problem: >>> I'm using C++ code to read stream blocks from the device (800,000 >>> samples with the USRP set to 8 MSPS, so basically 1 ms of data). Without >>> the LTE it works fine, I get only infrequent overruns and the rest of the >>> logic works fine. As soon as the LTE is plugged in and the corresponding >>> ethernet interface is up, the recv call can't get a whole block of data >>> (recv returns 0 bytes). If I ifconfig down the interface or unplug the LTE >>> it goes back to working just fine. Plug it back in or ifconfig up the >>> interface, problem returns. Of note, there is another network connection >>> up on the wifi so the LTE is getting a lower priority in the routing table >>> and there isn't any data going across it (I confirmed it with the >>> statistics in ifconfig for that interface). >>> >>> So troubleshooting so far: >>> I'm running the latest UHD code (3.11.1 - Just git pulled the latest >>> today and rebuilt it). >>> Works fine on Ubuntu 16.04. No issues with both connected (so it's not >>> my code :)) >>> There doesn't appear to be any firmware updates to apply to the Huawei >>> (always worth a shot) >>> The huawei_cdc_ncm linux driver doesn't appear to have had any updates >>> in the past couple years (so doesn't look like a linux driver update) >>> Nothing showing up from dmesg or in /var/log/syslog or /var/log/messages >>> related to failed recv's. >>> Made sure there wasn't any data going over the LTE to rule out it's >>> doing large data transfers >>> I tested with other USB devices in place of the LTE. Works fine. So >>> not the port or a general USB issue. >>> I tried opening the device with num_recv_frames=1024 to see if that >>> would help, no luck. >>> I also tried increasing the timeout from the default 0.1 to 0.2 on the >>> recv call with no luck there either. >>> >>> Any suggestions? >>> >>> So, two thoughts: >> >> The rPi USB power supply isn't really up to the task of supply >> spec-maximum power to each power. Perhaps your LTE device (combined with >> B205) is drawing too much power. >> >> The USB bus bandwidth is *per controller*, and perhaps there just isn't >> enough aggregate bandwidth left to service both devices. >> >> The B205 has no external-power input, as I recall, but it's mostly >> designed for USB3.0, where the per-port power is higher. >> You might try one of those "power booster" USB2.0 "Y" cables, and plug >> the "power only" plug into a 5.0V USB power supply. >> >> >> >> _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
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