#garfield Logs

Jan 06 2023

01:59 AM rue_mohr: I'm not too sure how to work out peak acceleration tho
02:09 AM rue_mohr: as all the velocity numbers are awful
10:49 AM rue_shop3: 26khz
10:52 AM rue_shop3: 720 lines
11:20 AM rue_mohr: https://github.com/TaraHoleInIt/funkyprobe85
01:16 PM aandrew: ok, EE trying to ME... please help me by showing me where I'm stupid
01:17 PM aandrew: I have a USB C charging port that melted the plastic around it
01:17 PM rue_mohr: huh
01:17 PM aandrew: like char/melt
01:17 PM rue_mohr: not surprised
01:18 PM aandrew: specific heat capcity of ABS is about 2J/g-cC
01:18 PM rue_mohr: how does anyone think those voltages/currents are reasonable anyhow?
01:18 PM aandrew: ABS melts at 200C
01:18 PM rue_mohr: esp on those tiny pins
01:18 PM aandrew: so if ambient is 20 and I estimate 10g of ABS
01:18 PM aandrew: that would be Q=mcdT or 3600J of energy to melt 10g of ABS
01:18 PM rue_mohr: I think they forget that after being made, the pins take on an oxide layer
01:18 PM aandrew: 3600J is 1Wh
01:19 PM aandrew: if the poor connection is only 1 ohm, that's 1.5W with a 1.5A charge current
01:19 PM rue_mohr: bad
01:19 PM aandrew: am I out to lunch on this? Iam I an OOM off or anything?
01:19 PM rue_mohr: it sounds good to me
01:19 PM rue_mohr: I'm not good with heat maths tho
01:20 PM rue_mohr: like, whats k for the connector
01:20 PM aandrew: I mean the connector spec is 30mOhm max per contact
01:20 PM aandrew: so ideally it should be 15mOhm
01:20 PM rue_mohr: hahaha
01:20 PM rue_mohr: maybe new
01:20 PM aandrew: yeah
01:22 PM aandrew: I think I need to build an mOhm meter
01:22 PM rue_mohr: :/ there is a lot of wind today, I should check up on the ballast holding down the tilt and pan mirror
01:22 PM rue_mohr: that in-circuit cap tester I made works good
01:23 PM rue_mohr: its kinda got a hint of a sitched amplifier
01:23 PM rue_mohr: switched,...
01:23 PM rue_mohr: uh, what are they called
01:26 PM aandrew: actually it's 2.25W with a poor 1 ohm connection
01:31 PM rue_mohr: so, how do we make industry think past the first 4 minutes a product exists?
01:57 PM aandrew: what do you mean?
01:58 PM aandrew: USB-C is very good
02:00 PM aandrew: I pull 100W all the time with no issue
02:00 PM aandrew: I'm pulling 57W right now in fact
02:01 PM aandrew: I really like USB C, with the sole exception that it's impossible to differentiate cables capable of 100W with cables capable of less, cables capable of 10Gbps witih those capable of 480 or 40Gbps.
02:01 PM aandrew: that sucks
02:01 PM aandrew: but one connector to rule them all? and mechanical design that tries to wear the cable over the port? very well done.
02:10 PM rue_mohr: mhm
03:01 PM aandrew: not to mention orientation agnostic..icy? that's like big in my book
03:44 PM polprog: https://polprog.net/rozne1/ircjunk/various/lturns.py
03:44 PM * polprog waves to rue_mohr
03:49 PM rue_mohr: I see
03:49 PM rue_mohr: you went python eh?
03:50 PM rue_mohr: but does it go the other ways?
03:50 PM rue_mohr: hmm,
03:50 PM polprog: as what L at how many turns?
03:50 PM rue_mohr: just a sec
03:50 PM polprog: i wrote it in python cause i needed it written fast
03:50 PM polprog: maybe ill rewrite it in c
03:51 PM rue_mohr: zippo:/tmp# inductor --help
03:51 PM rue_mohr: This program solves constant stuff.
03:51 PM rue_mohr: -h --help is the help your looking at
03:51 PM rue_mohr: -l --inductance set inductance
03:51 PM rue_mohr: -n --turns nuymber of turns
03:51 PM rue_mohr: -k --constant core constant
03:51 PM rue_mohr: you can specify two and it'll give you the other
03:51 PM rue_mohr: so, if you pull turns off a known inductor, you can work out k
03:51 PM rue_mohr: then use that k to work out turns for something else :]
03:52 PM rue_mohr: zippo:/tmp# inductor -n 50 -l 100u
03:52 PM rue_mohr: Inductance is: 100.000uH
03:52 PM rue_mohr: Turns is: 50.000
03:52 PM rue_mohr: Constant is: 40.000n
03:53 PM rue_mohr: zippo:/tmp# inductor -k 50n -l 1m
03:53 PM rue_mohr: Inductance is: 1.000mH
03:53 PM rue_mohr: Turns is: 141.421
03:53 PM rue_mohr: Constant is: 50.000n
03:53 PM rue_mohr: mm?
03:53 PM rue_mohr: :]
03:53 PM rue_mohr: BUT
03:54 PM rue_mohr: looking back, I'm not sure if I shouldn't be writing these in javascript to use on webpages
03:54 PM rue_mohr: ?
03:56 PM rue_mohr: I didn't know about """
03:57 PM Tom_L: :)
04:13 PM rue_mohr: https://github.com/SpenceKonde/ATTinyCore
04:13 PM rue_mohr: hahah, scroll down and see the non-supproted
04:13 PM rue_mohr: what they say about the T10
04:14 PM rue_mohr: did you send me a T10?
04:14 PM rue_mohr: I think you did ...
04:14 PM rue_mohr: I dont know how to program it, I think your programmer can
04:22 PM polprog: woohoo
04:22 PM polprog: the mixer works
04:22 PM polprog: i can bump AF up to 2Vpp before the spurs go up
04:27 PM rue_mohr: mmm RF
04:56 PM polprog: lovely, i can hear the demodulated AF on the GSM test set
04:56 PM polprog: despite the name it can go down to 20MHz
04:57 PM polprog: time to eat something
04:57 PM rue_mohr: nice
04:57 PM polprog: ill build the thing on copper clad on the weekend and add an aux in jack
04:58 PM polprog: did you put that toroid program up somewhere?
04:58 PM rue_mohr: I'm building an encoder 'probe'
04:58 PM rue_mohr: its just an inductor program... might be on github
04:58 PM rue_mohr: https://github.com/ruenahcmohr/inductor
04:59 PM rue_mohr: siprint and numcol are for scientific postfix IO
04:59 PM rue_mohr: cmnCmdOptions is my command line argument parser (uses callbacks)
05:16 PM polprog: cool!
05:16 PM polprog: i think ill go to bed
05:16 PM polprog: long day
05:16 PM polprog: im glad the mixer actually works
05:17 PM polprog: nighters
05:59 PM rue_mohr: ni
06:37 PM Tom_L: yes to both T10 questions
06:38 PM Tom_L: internal 11Mhz osc
06:39 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/avr/tiny10/
06:40 PM rue_mohr: I'm not completely sure were it is, I think I know
06:40 PM rue_mohr: I'v actually come up with things it could be used for since you were playing with it
06:41 PM Tom_L: did i send a board for it?
06:41 PM rue_mohr: yea, Its on a programming board
06:41 PM rue_mohr: iirc
06:41 PM rue_mohr: I think its one of your toner transfer boards
06:41 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/tiny/tinyTPI2.jpg
06:41 PM rue_mohr: yea
06:41 PM rue_mohr: but, tiny10, right?
06:42 PM Tom_L: yes
06:43 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/stamp2.jpg
06:43 PM Tom_L: hah
06:43 PM rue_mohr: mmm
06:44 PM rue_mohr: those were an inspiration weren't they?
06:44 PM rue_mohr: amazing how far it came so fast
06:44 PM Tom_L: hardly used it
06:44 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/sign.jpg
06:45 PM Tom_L: that was some time back
06:46 PM rue_mohr: heh
06:49 PM Tom_L: T10 uses TPI
06:49 PM rue_mohr: tpi, ok
06:50 PM Tom_L: FLIP
06:50 PM rue_mohr: not avrdude?
06:50 PM Tom_L: or that other 3rd party one
06:50 PM Tom_L: maybe
06:51 PM Tom_L: been too long
06:52 PM Tom_L: try a blinky
06:52 PM Tom_L: when it came out it was asm only, now gcc works on it
06:57 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/avr/tiny10/goodies/pwm/
06:57 PM Tom_L: that one is a siren iirc
06:57 PM Tom_L: piezo
06:57 PM rue_mohr: I'v a few things earlier in the queue for a bit
06:58 PM Tom_L: at one point i wasn't too bad at asm on that
06:59 PM rue_mohr: I was impressed enough with the code size to stay with C for the most part
07:00 PM rue_mohr: the portability is nice too
07:00 PM rue_mohr: I'v dragged in code from a few PC programs to various avr projects
07:00 PM rue_mohr: hows the work going for the kid?
07:00 PM Tom_L: both, good
07:01 PM rue_mohr: good show, there seems to be economic stalling going on, so there's no telling who is gonna fall when
07:01 PM Tom_L: https://www.youtube.com/watch?v=Gbq-Hi9wcU4
07:01 PM Tom_L: he runs a couple of those
07:01 PM Tom_L: 180' bed
07:02 PM rue_mohr: yup, you were saying they were recalibrating them
07:02 PM Tom_L: the other is doing HVAC lab testing for a heatpump program to get them to work below -20
07:02 PM rue_mohr: bed was out by a lot
07:02 PM rue_mohr: efficiency must be hurtin but ok
07:02 PM Tom_L: 2 companies have succeeded
07:03 PM Tom_L: for regions they currently won't work in
07:03 PM rue_mohr: yep
07:03 PM Tom_L: Traine and Johnson controls
07:03 PM rue_mohr: the big ones
07:03 PM Tom_L: he works for the latter
07:03 PM rue_mohr: we see a lot of it out here
07:04 PM Tom_L: in the engineering test lab
07:04 PM rue_mohr: nice
07:04 PM rue_mohr: microchip controllers I'd imagine
07:04 PM rue_mohr: 18F
07:04 PM Tom_L: for their age they're doing well
07:07 PM rue_mohr: not sure why indistry likes them so much
07:09 PM Tom_L: more efficient?
07:09 PM Tom_L: dunno
07:09 PM rue_shop3: doubt it
07:10 PM rue_shop3: I think thats still paged memory
07:10 PM rue_shop3: pretty sure you have to pay for the C compiler
07:10 PM Tom_L: no
07:10 PM Tom_L: for the T10?
07:10 PM Tom_L: i've used it
07:10 PM rue_shop3: no, the 18F
07:10 PM Tom_L: oh
07:11 PM Tom_L: midrange pic
07:11 PM Tom_L: i have one but it's old
07:11 PM rue_shop3: I class them as garbage
07:11 PM Tom_L: forget what it was called
07:11 PM Tom_L: ccs c
07:11 PM rue_shop3: see them in a lot of thigns tho
07:11 PM Tom_L: was it midrange or bigger?
07:12 PM Tom_L: i dunno
07:12 PM rue_shop3: I think mid
07:12 PM rue_shop3: I think joshua in #robotics is too young
07:12 PM rue_shop3: joke missed