**** BEGIN LOGGING AT Sat Mar 21 02:59:57 2020 Mar 21 03:30:18 zmatt Except for the Raspberry Pi of course. Mar 21 03:30:33 so I've heard, lol Mar 21 03:30:59 I've heard it' sounds bad too! I know it's a shock... Mar 21 03:33:07 yeah to get good quality audio using pwm would require an insane pwm frequency I think... at that point you're better off using a sigma-delta (aka delta-sigma) modulator Mar 21 03:37:25 generally they run at 300k to 450k frequency with a slightly complex filter, TI has some nice app notes regarding such things. That's with fairly high accuracy (IE >=16bit or 96db). Unfortunately the PI is like 12bit? I think? Mar 21 03:40:20 ? Mar 21 03:44:04 ah sorry I didn't mean pwm frequency, I meant clock to the pwm peripheral (which determines pwm frequency * number of duty cycle steps) Mar 21 03:46:14 and rpi originally was 11-bit 48 kHz (i.e. 98.304 MHz pwm clock), and later implemented 7-bit sigma-delta modulation at 781.25 kHz (100 MHz pwm clock) Mar 21 03:47:51 at it was originally "~48 kHz" so my guess would be the pwm clock was 100 MHz before too Mar 21 03:48:36 this reimplementation improved THD+N to -50 dB ... previously it was -20 dB ... ouch XD Mar 21 03:50:09 quantization noise was previously -60 dB and signal-correlated, new quantization noise floor is -93 dB and uncorrelated... that's not a bad achievement Mar 21 03:53:08 Good night... Mar 21 03:54:16 the old mode also wasn't actually PWM... it was actually already kinda closer to a crappy form of sigma-delta Mar 21 03:55:21 night Ken Mar 21 03:56:17 sigma delta has advantages over pwm. Just like using PDM has advantages over PWM. Keeping the frequency higher simplifies the order of the filtering needed. Mar 21 03:58:58 pdm is the output of sigma-delta modulation Mar 21 07:18:45 So I burnt my PocketBeagle board after 3 month of using. The power supply setup was: Mar 21 07:22:02 was... ? Mar 21 07:22:47 I don't know if you tried to paste multi-line text into chat but that doesn't work. use a paste service like pastebin.com to share multiline text Mar 21 07:24:03 External +5.07VDC via usb1 + native usb to computer. After a few seconds PB and my computer turns off. And when i started computer the PB only blinks once for some millisecond. Mar 21 07:25:06 what do you mean by "+5.07VDC via usb1" Mar 21 07:25:55 the only way to supply 5V to the pocketbeagle other than via the usb header it via P1.01 Mar 21 07:26:04 *other than via the usb connector Mar 21 07:28:01 I give the 5.07 volts from dc-dc converter to USB1. Mar 21 07:28:29 what do you mean by that? what pin are you talking about? Mar 21 07:30:30 5, 7, 9, 11, 13, 15 - usb1 port on PocketBeagle Mar 21 07:34:36 On P1 side. Mar 21 07:41:16 Siegurd: https://pastebin.com/raw/nJCbVsaA Mar 21 07:41:57 there is no way to power the beaglebone via any of the pins you mentioned Mar 21 07:42:32 the only pin that tolerates an externally supplied 5V is P1.05, which is an analog input for monitoring the usb1 vbus voltage Mar 21 07:43:34 the only pin on P1/P2 you can use to power the pocketbeagle is P1.01 Mar 21 07:48:06 I read that powering PB via P1.01 causes unstable work of board once in day. Mar 21 07:49:42 well that pin is the same pmic input that's typically used to power beaglebones and other AM335x devices, so any such issues must have been specific to some odd setup and/or due to some bug Mar 21 07:50:10 it's also, as I've already said, the only pin on P1/P2 that can be used to power the pocketbeagle Mar 21 07:51:34 (in theory P1.07 could be used, but only if you never use the micro-usb port on the pocketbeagle. it would be silly to do so however, and risk damaging the pocketbeagle and/or the PC if you have the pocketbeagle connected to one via usb) Mar 21 07:54:56 Is there any way to fix dead PB biard? Mar 21 07:58:23 if the power led only blinks briefly that typically indicates the pmic is unable to power up the board because it has detected a short-circuit Mar 21 07:58:57 if there's no external connections that could cause such a short-circuit it probably means the SoC itself got damaged Mar 21 07:59:52 replacing that would be way more expensive than a new board Mar 21 12:33:57 zmatt what do you use your beagle boards for? Mar 21 20:53:58 Hi just got a BB AI. Whenever I try to run the classification demo in Cloud 9, I get a bind: Address already in usebind: Address already in use o: server_thread(): bind(8080) failed Mar 21 20:54:21 In the demo video, that happens too, but I don't have another app running Mar 21 21:21:51 Hello, I need to check the DHCP lease, but there is no /var/lib/dhcp/dhclient.leases file Mar 21 21:22:24 is the dhcp lease stored somewhere? Mar 21 21:48:03 I have some problems running linux on kvm on bb-x15 Mar 21 21:48:09 I don't have any output Mar 21 21:48:36 what kernel parameters should I pass to the guest machine? Mar 21 22:15:34 the dhcp leasing in a log is in /var/log/syslog.1 with dhclient it will state renewal in <#> seconds you can get the time it expires from subtracting the time the entry was loged. Mar 21 22:15:45 uniqdom ^ Mar 21 22:18:15 uniqdom also you need root or group adm permissions to read the log (not my doing) Mar 21 22:40:11 that seems like an awful way to obtain dhcp lease information Mar 21 22:40:37 doesn't connman have some command you can use to query whatever information you're looking for? Mar 21 22:40:44 or state file you can read it from Mar 21 22:42:16 why would you care about the dhcp lease anyway? Mar 21 22:42:25 seems like an odd thing to be interested in Mar 21 22:42:45 (instead of just checking the network settings) Mar 21 22:50:47 (and if you were to want to extract information from system logs, please get it from journal instead of logfiles, since journal is effectively a database indexed on every field you can easily filter for records you're looking for) Mar 21 22:52:27 hmm I don't know the reason they wanted it zmatt. Any guess would likely be wrong in any case. :D Mar 21 23:27:43 I need to setup a secondary Internet access for redundancy. Primary access will be eth0 and secondary will be ppp0 (wvdial). I'm setting a script to manage both connections. If eth0 cable is unplugged, wvdial dials a connection using a modem. if cable is plugged back I need to kill wvial to use eth0. The thing is that eth0 is contacting the dhcp server but it doesn't setup a default route, because at that time wvdial is still running there Mar 21 23:27:43 is an already default route (so wvdial can reach Internet) I guess. Mar 21 23:28:26 so I want to read the lease to know what is the router (default gateway) to set a route rule Mar 21 23:28:47 that just sounds like a bug or misfeature in connman, linux has no problem with multiple default routes Mar 21 23:29:03 systemd-networkd would add a default route for eth0 regardless of any existing one Mar 21 23:30:07 (and you'd use metric to determine which one takes priority) Mar 21 23:32:21 e.g. on my laptop when I'm connected via wifi and then also plug in ethernet: https://pastebin.com/raw/2dwi2Cxy Mar 21 23:33:05 new connections would begin to use the lower-metric route via eth0 while existing connections continue to use wlan0 Mar 21 23:33:58 so if you can't convince connman to behave sanely it may be a good time to switch to a better network manager (like systemd-networkd) Mar 21 23:42:05 I didn't knew about metrics, I have to learn that. Mar 22 00:32:40 uniqdom it's good to ask questions because often someone will point out what you hadn't considered or didn't know. **** ENDING LOGGING AT Sun Mar 22 02:59:58 2020