**** BEGIN LOGGING AT Fri Jan 26 03:00:03 2018 Jan 26 07:52:30 hello Jan 26 07:52:48 I have an issue about bb blue output signals Jan 26 07:52:52 elcrcp: I think the serve outputs of the blue are open-drain Jan 26 07:52:55 *servo Jan 26 07:53:06 is there no hardware manual or something? Jan 26 07:53:29 hi zmatt Jan 26 07:54:41 I didn't see anything about electrical characteristics about bb blue Jan 26 07:54:52 ah wait, motor outputs aren't servo outputs Jan 26 07:55:06 yes Jan 26 07:55:25 motor outputs are powered directly from V_BATT Jan 26 07:55:35 do you have a battery attached? Jan 26 07:55:56 no, only on usb, so I should connect 12v input too Jan 26 07:56:33 do spi pins also powered on battery? Jan 26 07:56:45 because spi signals were also on 100mV levels Jan 26 07:56:50 I don't actually know if providing VCC suffices, it might actually require a battery Jan 26 07:56:53 no, definitely not Jan 26 07:57:01 spi on which terminals? Jan 26 07:57:11 s1.1 Jan 26 07:57:15 scl Jan 26 07:57:19 mosi and miso Jan 26 07:57:28 sck you mean Jan 26 07:57:32 yea Jan 26 07:57:33 those connect directly to the cpu Jan 26 07:58:33 interesting then Jan 26 07:58:40 maybe they need a pull up? Jan 26 07:58:51 spi is not open-drain Jan 26 07:58:54 or they do have a pull up connected to battery Jan 26 07:59:09 battery voltage would destroy the am335x Jan 26 07:59:22 spi does not require pull-ups Jan 26 07:59:31 i see Jan 26 07:59:32 having 100mV level is interesting on these pins Jan 26 08:00:15 you're seeing a signal with 100mV amplitude, or are they just hovering at 100 mV ? Jan 26 08:00:39 amplitude around 100mV Jan 26 08:01:53 that is really bizarre, this is without anything connected to it? Jan 26 08:02:03 yes Jan 26 08:02:18 I observed 3 different outs Jan 26 08:02:26 first motor outs Jan 26 08:02:55 there were correct pwm signals but 100mV, then servos, pwm signals were 3.3v as expected Jan 26 08:03:11 power rail wasn't working as no external power connected to card Jan 26 08:03:32 and spi pins with loopback demo, spi signals were also around 100mV Jan 26 08:04:36 so, for the motor outputs it's understandable, but I have no explanation for the spi pins Jan 26 08:05:51 ok, thanks a lot Jan 26 08:06:02 you helped me again =) Jan 26 08:06:13 I think I got a few idea to try Jan 26 08:06:30 inform you after tests =) Jan 26 08:11:33 all the different power domains on the blue seem like a headache to me Jan 26 08:12:10 the bbblue has motor drivers on board? interesting Jan 26 08:14:00 and hazardous too, e.g. the GPS header provides a 5V supply which is always-on, which makes it a very bad idea to actually use that to power a GPS module connected to the uart I/O on that header, since that is very likely to destroy those I/O if the am335x is powered off Jan 26 08:14:15 thinkfat: yes it does Jan 26 08:22:18 yes, drawing a few lines in a layout tool is easy... Jan 26 08:25:53 it's sooo easy to make mistakes with multiple power domains Jan 26 08:27:32 ok I made some tests Jan 26 08:28:31 as you explained, motor outs giving out input voltage Jan 26 08:29:34 I don't know if it's designed to be used with only VCC power though... motors tends to require high peak current, which is exactly what a battery is good at Jan 26 08:30:02 spi pins confused me, last night I sow 100mV voltage levels on spi pins but now I'm seeing 2v for sck 3.3v on mosi / miso Jan 26 08:30:38 that 2v still sounds bizarre Jan 26 08:31:18 yes, it is normally in dead space Jan 26 08:32:47 but I think 2v is acceptable for 3.3 logic Jan 26 08:33:00 but impossible for 5v logic Jan 26 08:33:14 hello all Jan 26 08:33:14 acceptable but undefined. Jan 26 08:33:28 usually the levels are at 0.2*vcc and 0.8*vcc Jan 26 08:33:47 elcrcp: 2v might happen if the pin is floating and internal pull-up/down is disabled Jan 26 08:33:54 I am not an expert in embedded and low level programming and I wanted to imply the capabilities of the BBBlue to write my own flight controller. I have a few questions regarding the same.... Jan 26 08:34:00 but it's really not good for a digital i/o Jan 26 08:34:46 The first is that I was told a RTOS is essential for a Flight Controller, is there any tutorial on how to install, implement and use an RTOS on the blue? Jan 26 08:34:54 LetoThe2nd: see Elec tab of my pins spreadsheet for the actual values for the am335x ( https://goo.gl/Jkcg0w ) Jan 26 08:35:10 you right, I didn't touch any setting, it is on default settings Jan 26 08:35:20 Also I remember executing the following command: sudo /opt/scripts/tools/update_kernel.sh --ti-rt-channel --lts-4_4 to install an RT Kernel, what implications does this have Jan 26 08:35:32 elcrcp: it should have internal pull up/down in default config Jan 26 08:35:34 maybe I can use a level shifter if i cant resolve this Jan 26 08:35:40 zmatt: :-) Jan 26 08:36:22 elcrcp: you shouldn't try to work around this with a level shifter but figure out what is causing this and fix the problem Jan 26 08:38:52 I'm not good with arm unfortunately, I know arm outputs can be set on with pullup and pulldowns but I have no idea where to look at in bb blue Jan 26 08:39:24 any suggestion? Jan 26 08:40:43 elcrcp: arm is just the cpu core, has nothing to do with i/o. I do have a nice script to inspect the state of the current pin config, but right now I only have variants for the black and the green-wireless Jan 26 08:41:32 I'm actually working on a pin table for the blue right now since I've had to consult the schematic a bit too often, so I should be able to fix a variant of my script for the blue as well Jan 26 08:46:38 you can find my show-pins script here: https://github.com/mvduin/bbb-pin-utils/ Jan 26 08:47:33 thanks, checking Jan 26 08:47:54 the blue's spi sck (S1.1/S1.2 pin 5) would be listed as pin 100 / P9.31 Jan 26 08:52:39 P9.31 / hdmi audio clk 100 fast rx down 3 spi 1 clk ocp/P9_31_pinmux (pinmux_P9_31_spi_pin) P9.29 / hdmi audio fs 101 fast rx down 3 spi 1 d0 miso ocp/P9_29_pinmux (pinmux_P9_29_spi_pin) P9.30 102 fast rx down 3 spi 1 d1 mosi ocp/P9_30_pinmux (pinmux_P9_30_spi_pin) Jan 26 08:53:00 please don't paste multi-line output into an irc channel Jan 26 08:53:05 use a paste service like pastebin.com Jan 26 08:53:16 sorry Jan 26 08:55:53 https://snag.gy/BZWDUf.jpg Jan 26 08:57:10 they are in pulldown state Jan 26 08:57:37 yeah, though I should note the internal pulls are really weak (100K ±50%) Jan 26 08:58:02 I'm not sure whether spi clk is driven outside transfers or not Jan 26 08:58:05 it might not be Jan 26 08:58:48 if there's accidently an external weak pull-up (I haven't checked) then that could explain the 2v Jan 26 08:59:05 it should still to go 3.3v during a transfer however Jan 26 08:59:50 hmm, I don't see anything in the schematic though... it just seems to connect to S1.1 and S1.2 Jan 26 09:03:18 hmm, well actually I have a spi device to check but it is logic 5 so I have to use a level shifter anyway Jan 26 09:03:45 I should try it Jan 26 09:06:13 of course you don't really need an spi device to check, you can just do an external loopback test (mosi->miso) Jan 26 10:04:03 jkridner[m]: probably not a huge deal, but I regret to inform you that bluetooth audio (a2dp) output is not going to work on the blue, and input will not work without kernel patch. the clk and fsync are connected to those of the receive-section, which are only used when receive is async to transmit (which isn't actually supported by the mcasp driver right now) and can't be used for transmit Jan 26 10:36:25 jkridner[m]: it's worth noting that everything you need for the wl18xx is available on the pins that belong to vdd_hv5 (pins 66-83), so you can just put vdd_hv5 at 1.8V and completely avoid the need for level shifters Jan 26 10:37:04 or wait, does the osd335x not allow that? Jan 26 10:40:11 it doesn't. lame. Jan 26 10:41:36 the osd335x-sm does allow it Jan 26 14:46:12 python remote debugging question, using pydev and remote system explorer, how do i remote debug a project that i have on my ubuntu on the bbb? Jan 26 14:51:00 zarzar: have tried doing ssh? Jan 26 14:51:05 you* Jan 26 14:51:38 krish-iyer: RSE is connected via ssh Jan 26 14:53:32 then you just have to login and you ll be able to browse files and debug it remotely Jan 26 14:53:59 debugging doesn;t seem to work for some reason Jan 26 14:54:46 I will prefer an IDE for debugging the projects like eclipse or pycharm Jan 26 14:55:11 i am using eclipse with pydev Jan 26 15:00:24 ok so i have to transfer the files via sshpass or some other file transfer then run, is there a better way? Jan 26 15:01:10 no, I tranfer files and then running it won't be a good idea Jan 26 15:01:22 ? Jan 26 15:02:59 think* Jan 26 15:26:03 I'm assuming you googled "pydev remote debugging" ? Jan 26 16:10:38 any thoughts about linux foundation adopting linux boot? Jan 26 16:11:19 I'm suck on this looking for help.. I have custom hardware, based on BBB, SD card booting and working great.. Issues booting form eMMC, from the SD card boot I can partition, mount, flash the eMMC.. when booting from the eMMC, u-boot starts, by the time it tries to start the kernel u-boot is having MMC issue. Jan 26 16:11:54 here is u-boot outputs: https://pastebin.com/jdzDzbKT Jan 26 16:15:25 and here is one from u-boot console, trying to use the u-boot mmc command: https://pastebin.com/msFSg6Ta Jan 26 20:58:46 is there a pin on the beaglebone to monitor if it's shutdown or not (from an external microcontroller)? Like, if it's on is one of the pins high vs when it's off, the pin is low? Jan 26 21:51:01 answer, yes: pin 9 Jan 27 00:07:37 etanner: hard to say much based on so little info... Jan 27 00:08:33 etanner: what happens if you try explicitly selecting eMMC using "mmc dev 1" (assuming it's mmc1 in your design) ? Jan 27 00:19:24 ayjay_t: in cases where you have a need for a complicated boot process I guess it makes more sense than stuffing (e.g.) u-boot with ever more bloat Jan 27 00:27:48 seems to be mostly about x86 though Jan 27 00:28:01 which is a godawful mess to begin with **** ENDING LOGGING AT Sat Jan 27 03:00:02 2018