#garfield Logs

Sep 24 2023

12:27 AM aandrew: awww that's so cute
12:38 AM aandrew: built it or aliexpress'd it?
01:41 AM rue_mohr: just made it today
01:41 AM rue_mohr: on of the japaneese twitter people did one first
01:41 AM rue_mohr: I kinda copied it
01:03 PM polprog: whats up rue?
01:08 PM rue_mohr: hmm what was up...
01:08 PM rue_mohr: drat, I dont know what I was going to talk about
01:09 PM polprog: heh
01:09 PM rue_mohr: I need ideas to finish filling a new sticker
01:09 PM polprog: sorry im not active recently
01:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/Untitled.png
01:09 PM polprog: work eats me
01:09 PM rue_mohr: yea yea, I know your doing coool things and just not talking about it
01:09 PM polprog: im trying to get linux running on this SBC
01:10 PM polprog: https://polprog.net/rozne1/ircjunk/mini210/mini210.html
01:11 PM rue_mohr: what are the challanges?
01:13 PM polprog: Chinese documentation, and the only known working bootloader for this particular board is some chinese black box that can only boot android and linux 2.6
01:13 PM Tom_L: boot 2.6 and upgrade
01:13 PM Tom_L: :)
01:13 PM polprog: But the chip is supported in u-boot, i have JTAG access (very broken), and the schematics
01:13 PM polprog: So i am basically trying to get u-boot working on it
01:14 PM polprog: Tom_L: i really really with there was a kernel module that would just let you replace Linux in memory with a different kernel
01:14 PM polprog: something like LOADLIN for DOS is
01:14 PM Tom_L: i'm building a kernel for the rpi atm
01:14 PM polprog: i am learning a great deal with this board
01:14 PM polprog: and i have like 5 others in the queue
01:15 PM polprog: rue_mohr: as for the stickers - i like the smiley from the hackers movie, i put it on a lot of things
01:15 PM polprog: on the last amiga party I just plopped a 5.25" disk on teh scanner and made a sheet of scaled down photocopies of it
01:15 PM polprog: as stickers
01:16 PM polprog: and I also made a few 1:1 scaled copies :D
01:16 PM polprog: that meter plate looks a bit like a ouija board
01:17 PM rue_mohr: so get a bootdisk with 2.6 on it that boots a newer version
01:17 PM rue_mohr: chainload
01:18 PM polprog: it's arm
01:18 PM rue_mohr: whatever
01:18 PM polprog: there is no boot disks. It loads the kernel directly
01:18 PM rue_mohr: "disc"
01:18 PM polprog: the thing is, I dont like the chinese bootloader
01:18 PM polprog: I want u-boot
01:18 PM rue_mohr: k
01:18 PM polprog: And i want to learn stuff along the way
01:19 PM polprog: I have the vendors kernel as well, once i get u-boot working i will work on getting that to boot
01:21 PM polprog: its something to keep me busy during evenings
01:22 PM polprog: what are you making now rue? im not often on twitter recently
01:24 PM rue_mohr: ok, last poke-in on this sticker
01:25 PM rue_mohr: should it be anti-cloud or anti-AI?
01:25 PM polprog: anti-AI
01:25 PM rue_mohr: not doing lots of descent stuff
01:25 PM polprog: something like
01:25 PM rue_mohr: ok
01:25 PM polprog: "Linear Algebra powered!"
01:27 PM rue_mohr: doing an AI in a circle with a strike
01:27 PM polprog: thats good too
01:27 PM rue_mohr: but you cant draw a circle in inkscape aparently..
01:27 PM polprog: huh
01:28 PM polprog: you should be able to do an oval and hold control to lock teh aspect ratio
01:32 PM rue_mohr: it puts a dividing line in like a pie
01:32 PM rue_mohr: its ok, I just draw things up in dxf and import them
01:33 PM rue_mohr: copy/paste edit
01:33 PM polprog: oh that
01:33 PM polprog: you dont need to use that semicircle feature
01:33 PM polprog: ive been making circles allright in inkscape
01:33 PM rue_mohr: its created!
01:34 PM rue_mohr: I'll show you what I hve
01:34 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/Untitled.png
01:35 PM polprog: haha
01:35 PM polprog: good!
01:35 PM rue_mohr: I dont think I can fit anything more in those remaining gaps
01:35 PM polprog: printing in color?
01:35 PM polprog: I like to fit the print date there
01:35 PM rue_mohr: I'll change it all up, it'll be holographic
01:35 PM polprog: ooooh
01:35 PM polprog: neato
01:35 PM rue_mohr: did you see the other...
01:36 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1290482.jpg
01:36 PM rue_mohr: did you see that?
01:36 PM rue_mohr: want one?
01:36 PM rue_mohr: I just had to have them printed to get the scale refrence
01:36 PM polprog: hahah thats a good one
01:36 PM polprog: you are right we should make a sticker swap
01:37 PM rue_mohr: in that frame, I can do a new scale for a 85C1 meter
01:37 PM rue_mohr: which is why I made it that size
01:37 PM rue_mohr: now that I have the template I can make everything to scale
01:39 PM polprog: clever
01:41 PM rue_mohr: I kind had to, they didn't understand me needing to keep everything in scale
01:42 PM rue_mohr: they put borders on my first design, and didn't understand my question about weather the borders were inside or outside the design
01:45 PM polprog: where are you ordering?
02:07 PM rue_shop2: stickermule
02:08 PM rue_shop2: you didn't see the onslaught of ads everywhere?
02:23 PM aandrew: got a kitchen table and ottoman, feels good to eat sitting somewhere respectable again
02:23 PM aandrew: couch is backordered for another week or two unfortunately
02:23 PM aandrew: but this is a major step up
02:25 PM rue_mohr: backordered!?
02:25 PM rue_mohr: particular couch then?
02:25 PM aandrew: yeah the couch is
02:26 PM aandrew: as for stickers, I am going to get a bunch of these made up and put them in the bathrooms at TAE as a way of introducing myself to the company: https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fg75adsgm03m41.jpg
02:27 PM rue_mohr: hahah
08:50 PM rue_mohr: ok, well I got a pulley "done" for the big cnc
08:50 PM rue_mohr: I have to make another...
08:50 PM rue_mohr: I wonder if I should look again at the prices of 100:1 synchro belt reducers...
08:51 PM Tom_L: machining went ok this time?
08:52 PM rue_mohr: Polprog how do we make the slideshow control a floating thing bound to a window edge?
08:52 PM rue_mohr: Tom_L, well
08:52 PM rue_mohr: one bearing pocket I made too big, and the other was just small enough to pinch the bearing a bit and make it run a bit thick
08:52 PM rue_mohr: it seems to have balanced ok tho
08:53 PM rue_mohr: lets see, if I'm about 5:1 on each
08:53 PM rue_mohr: 10000, 2000, 400
08:53 PM rue_mohr: so, its 2000rpm peak
08:53 PM rue_mohr: oh there is a step missing
08:54 PM rue_mohr: (motor) 10000, 2000, 400, 80 (chain drive)
08:54 PM rue_mohr: 3 stages of ~5:1
08:54 PM rue_mohr: this pulley was the 400 then
08:54 PM rue_mohr: so yea, its ok
08:55 PM rue_mohr: and 80rpm about be about 1m/s
08:56 PM rue_mohr: suppose that motor pulley should be steel
09:48 PM aandrew: wow, now that was an afternoon. went down to a tiny car show (pints and pistons) in san clemete, ended up staying for like 5h chatting. met another EE with the same mentality we have, son got a ride in a 60s jag type e and sat in the ee's ford gt40
09:48 PM aandrew: going to the world's biggest weekly car show next weekend in the same town: https://www.southoccarsandcoffee.com/
09:50 PM rue_mohr: :)
09:51 PM aandrew: dude does precision machining, high end analog design, I think he said he's 67 end of the year
09:51 PM aandrew: matthew's absolutley hooked now. He was really into this before but now there's no turning back
09:51 PM rue_mohr: :]
10:55 PM aandrew: rue_mohr: you've probably got some insight here... how do I make a regular old (9g) servo as quiet as possible? It's the gears making the noise for the most part. do metal gears reduce noise?
11:04 PM rue_mohr: hah
11:04 PM rue_mohr: good question...
11:05 PM rue_mohr: I wonder what grease would do
11:05 PM rue_mohr: can you just use a stepper instead?
11:05 PM rue_mohr: how much torque do you need?
11:14 PM aandrew: I could probably use a small stepper
11:18 PM rue_mohr: much quieter
11:18 PM rue_mohr: so..
11:18 PM rue_mohr: I did that tiny13 hoby-pwm->stepper controller
11:19 PM rue_mohr: mmmm?
11:21 PM aandrew: hm?
11:23 PM rue_mohr: it takes 0.5ms -> 2.5 ms pulses and uses them to control the position of a stepper motor
11:23 PM aandrew: ahh interesting
11:23 PM rue_mohr: you ... didn't see that twitter post either....
11:23 PM aandrew: I'm remembering something about that ... very faintly
11:23 PM aandrew: I am almost never on twitter these days
11:23 PM aandrew: that platform's mostly dead
11:23 PM rue_mohr: you should just follow me and check in every few days
11:24 PM rue_mohr: stand by...
11:24 PM rue_mohr: searching...
11:25 PM aandrew: http://www.cs.cmu.edu/~wkw/humour/carproblems.txt
11:25 PM rue_mohr: you did see the interactive ttl chip, RIGHT?
11:25 PM rue_mohr: the svg
11:25 PM rue_mohr: ?
11:28 PM rue_mohr: you didn't did you
11:28 PM rue_mohr: http://ruemohr.org/~ircjunk/programming/74xx138-IA.svg
11:28 PM rue_mohr: click the input pins, they change state and the outputs change
11:29 PM rue_mohr: (dont hit the black labels, they dont interact)
11:29 PM rue_mohr: found it, posting on youtube..
11:31 PM aandrew: I saw some of the eraly work on it yes
11:32 PM aandrew: that is pretty slick
11:33 PM rue_mohr: gawd it takes forever to post a vid on youtube
11:33 PM rue_mohr: https://youtu.be/hz8tAq69oEs
11:34 PM rue_mohr: it does acceleration & velocity control and position buffering and all that jazz so it shouldn't be able to lose pulses
11:35 PM rue_mohr: that wasn't the best video, but whatever
11:36 PM rue_mohr: aandrew, now that I did all that your gone aren't ya?
11:45 PM aandrew: nice video
11:45 PM aandrew: do you run into issues with creep or are you zeroing somehow
11:45 PM rue_mohr: no it tracks everything