**** BEGIN LOGGING AT Sat Aug 19 03:00:01 2017
Aug 19 06:59:19 <Ragnarokkr> does anyone know what adafruits python function ADC.read_raw() outputs
Aug 19 07:11:20 <veremitz> Ragnarokkr: I would be very surprised if the code doesn't tell you .. have you checked the source? I guarantee you it will be up on github ..
Aug 19 09:29:59 <zmatt> voltage / 1.8v
Aug 19 09:30:44 <zmatt> (this answer was powered by... looking at the source code)
Aug 19 09:31:56 <zmatt> I honestly have no idea why so much of this lib is written in C... most of it just consists of reading/writing sysfs files
Aug 19 09:34:45 <zmatt> and of course they never drop the global interpreter lock so instead of blocking just the calling thread they end up blocking all threads
Aug 19 09:45:27 <Ragnarokkr> voltage / 1.8v doesn't seem right, it's printing out values between 0.0 and 3200.0
Aug 19 09:46:25 <zmatt> ah wait, theres read and read_raw ... I was looking at read
Aug 19 09:46:57 <zmatt> I'd expect read_raw to be 0-4095 then, since that's the output range of the adc
Aug 19 09:47:17 <zmatt> (returned as float instead of integer because they're sillybeans)
Aug 19 09:47:39 <zmatt> hmm
Aug 19 09:49:23 <Ragnarokkr> that makes sense, though the python adc is too slow to be useful
Aug 19 09:49:46 <Ragnarokkr> is there a good pru library that I could use with C++ for ADC and PWM
Aug 19 09:51:35 <veremitz> I'm pretty sure the BBB adafruit library was shelved a few years ago
Aug 19 09:51:59 <zmatt> "too slow to be useful" .. what sort of sample rate do you need?
Aug 19 09:52:12 <veremitz> definitely a case of YMMV I'd say
Aug 19 09:52:32 <zmatt> you may want to change the adc config, the overlay supplied by default uses silly slow settings
Aug 19 09:52:36 <veremitz> you can read a file a few thousand times a second, surely?!
Aug 19 09:52:55 <veremitz> maybe few hundred
Aug 19 09:53:18 <zmatt> maybe a few hundred thousand
Aug 19 09:53:20 <zmatt> maybe more
Aug 19 09:53:23 <zmatt> dunno actually
Aug 19 09:53:38 <veremitz> will sysfs respond that fast, zmatt?!
Aug 19 09:53:43 <zmatt> you can probably do it faster in pure python than using the adafruit lib
Aug 19 09:53:52 <veremitz> there is that ^
Aug 19 09:53:55 <Ragnarokkr> I'm not sure, enough to record a NTSC video signal
Aug 19 09:54:59 <veremitz> good grief, why -this- way?!
Aug 19 09:55:36 <zmatt> including color? yeah forget about it
Aug 19 09:57:58 <Ragnarokkr> ya, I guess 10+Msamples/second is a little much to ask for
Aug 19 09:58:25 <veremitz> not forgetting nyquist
Aug 19 09:59:35 <veremitz> demodulate first .. you would have a chance ..
Aug 19 10:00:01 <veremitz> ah hold on .. that is ~10MHz .. TV bands are ~400-500Mhz
Aug 19 10:00:17 <zmatt> iirc the max of the adc is around 1MHz, and the result is quite noisy
Aug 19 10:01:17 <Ragnarokkr> it was a back of the envelope calculation pixel*pixels*frames
Aug 19 10:01:44 <Ragnarokkr> is PWM fast enough to create a 400-500Mhz signal
Aug 19 10:02:03 <veremitz> nope .. same reasoning
Aug 19 10:02:41 <veremitz> unless you could find some way of exploiting a harmonic .. but good luck with doing that reliably ..
Aug 19 10:07:42 <zmatt> I think it may be possible with eHRPWM
Aug 19 10:07:59 <zmatt> iirc ds2 has done something like that
Aug 19 10:14:42 <zmatt> but really, if you want video in and out, you really should consider a more suitable SoC
Aug 19 10:17:03 <Ragnarokkr> i don't have any experience with video and i thought it was work looking into since i had this board lying around
Aug 19 10:17:45 <veremitz> the beagle cpu is a control chip, not a video chip.
Aug 19 10:18:05 <veremitz> TI make much more video-centric SoC too
Aug 19 10:20:13 <veremitz> have a look for the davinci chips, for example
Aug 19 10:20:27 <zmatt> (ntsc only has 6 MHz bandwidth btw)
Aug 19 10:21:49 <veremitz> zmatt: still outta bounds to an am335x :p
Aug 19 10:22:29 <veremitz> is/was PAL 8MHz?
Aug 19 10:23:05 <veremitz> been digital for long enough that I forgot
Aug 19 10:24:53 <veremitz> yup PAL channel is 8
Aug 19 10:25:00 <veremitz> NTTSC only 6
Aug 19 19:34:55 <Franz_> hi there, I am setting up my beaglebone black with the new debian and logged in through ssh, but the default pwd does not seem to work
Aug 19 19:35:14 <Franz_> I used temppwd as the password
Aug 19 19:35:19 <Franz_> is this correct?
Aug 19 19:36:33 <Franz_> Franz-Air:~ Franz$ ssh root@beaglebone.local The authenticity of host 'beaglebone.local (fe80::caa0:30ff:febf:7db1%en4)' can't be established. ECDSA key fingerprint is SHA256:LPsHNW/r3y1AOvy5U/re/L7Q0iYfSP5v2BWJ94s7lc4. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'beaglebone.local,fe80::caa0:30ff:febf:7db1%en4' (ECDSA) to the list of known hosts. Debian GNU/Linux 8  BeagleBoard.org Debian Ima
Aug 19 19:36:58 <Franz_> default username:password is [debian:temppwd]  root@beaglebone.local's password: 
Aug 19 19:37:03 <Franz_> this is what I see
Aug 19 19:37:37 <Franz_> sorry, I am a rookie here..
Aug 19 19:37:59 <zmatt> Franz_: username debian
Aug 19 19:38:16 <Franz_> I see, so not root
Aug 19 19:38:54 <Franz_> awesome, it works :-)
Aug 19 19:38:54 <zmatt> it's not good practice to casually work as root, better to just use sudo for commands that require root privileges
Aug 19 19:39:15 <Franz_> wow, many thanks!!
Aug 19 19:40:24 <Franz_> when it comes to the root pwd on the debian, is this also known?
Aug 19 19:40:28 <Franz_> if I ever need it?
Aug 19 19:40:41 <Franz_> or can I change it, despite not logged in as "root" but as "debian"
Aug 19 19:41:30 <zmatt> you can just log in as root and then use 'sudo -i' to get a root shell
Aug 19 19:41:36 <zmatt> log in as debian I mean, sorry
Aug 19 19:42:37 <zmatt> and yeah you can also assign a password to the root account then, but sshd is configured by default to disallow logging in as root using a password (it only allows it using public-key authentication)
Aug 19 19:45:29 <Franz_> Thanks for the help!
**** ENDING LOGGING AT Sun Aug 20 03:00:01 2017