#garfield Logs

Jan 31 2021

02:03 PM spline: https://twitter.com/litcapital/status/1355878277706080260
04:29 PM rue_mohr: so I got it
04:30 PM rue_mohr: I have the stm32 using its DMA to transfer a 256 byte table repeatedly to an 8 bit port
04:30 PM rue_mohr: with each update triggered by a timer
04:30 PM Tom_L: nice, what's this for?
04:30 PM rue_mohr: a hearing profiler for ma
04:31 PM rue_mohr: and other things
04:31 PM rue_mohr: the ability to push pattern tables to output ports will be hancy
04:31 PM rue_mohr: handy
04:31 PM rue_mohr: I'm about to fall asleep
04:31 PM rue_mohr: which is annoying
04:31 PM Tom_L: yeah you got day and night mixed up
04:32 PM rue_mohr: I think what I want to do more than working on any project is to just be focused on only one project
04:33 PM Tom_L: you might get something done that way
04:36 PM rue_mohr: I need to clear space in the shop so I can strip down printers to make room for all the other stuff that followed me home
04:38 PM rue_mohr: for the stm32 thing I need to hook up an 8 bit dac
04:38 PM rue_mohr: next
04:39 PM Tom_L: z must have gone overseas
04:40 PM rue_mohr: I wonder
04:40 PM Tom_L: military screwed him up
04:40 PM rue_mohr: yup
06:32 PM rue_mohr: ok 8 bit DAC
06:32 PM rue_mohr: parallel
06:32 PM rue_mohr: I'll need to buffer it with a 74541
06:32 PM rue_mohr: I have some R-2R somewhere already made
06:41 PM rue_mohr: polprog, your still alive, right?
06:42 PM Tom_L: where are these new ppl coming from?
06:42 PM Tom_L: twitter?
06:42 PM rue_mohr: well, ye.
06:43 PM rue_mohr: darkrose, do you still have a lathe and printer?
06:43 PM rue_mohr: only 2 of them can exist at once?...
06:44 PM Tom_L: it's da law!
06:44 PM rue_mohr: hmm, so I think I can just plug an R-2R sip into the output side of a 74ls541
06:44 PM rue_mohr: one pin has to ground, and I think thats right
06:45 PM rue_mohr: I have to get stuff out of my truck >:|
06:45 PM rue_mohr: https://fr.tek.com/-/media/sites/default/files/2018-03/image-2-tutorial-r2r-dac.jpg
06:45 PM Tom_L: dunno about you but it's cold outside here!
06:45 PM rue_mohr: yes, one end is grounded, perfect
06:46 PM rue_mohr: were at about 4 or 5?
06:46 PM rue_mohr: oh warmer now
06:46 PM rue_mohr: 6.5c
06:46 PM rue_mohr: its going to snow in feb
06:47 PM rue_mohr: not sure how this will go down
06:47 PM Tom_L: 30ish here
06:47 PM rue_mohr: I suspect a cold front will blow in and it'll go down fast
08:48 PM rue_mohr: Tom_L,
08:48 PM rue_mohr: https://twitter.com/RueNahcMohr/status/1356068895199621122
08:50 PM Tom_L: no sound
08:50 PM Tom_L: your mill?
08:50 PM rue_mohr: yea
08:50 PM rue_mohr: its a bit gravely
08:50 PM Tom_L: sprayer parts
08:50 PM rue_mohr: yep
08:50 PM rue_mohr: thats the jig you devised :)
08:50 PM Tom_L: iirc i made some of that part
08:50 PM rue_mohr: yup
08:51 PM rue_mohr: I think he used them
08:51 PM Tom_L: oh, the plastic model you printed
08:51 PM rue_mohr: yep
08:51 PM Tom_L: nice
08:51 PM Tom_L: save time?
08:51 PM rue_mohr: yes
08:51 PM rue_mohr: I had to show the co-worker how to use it a few times
08:52 PM Tom_L: i dunno if i still have those for mine
08:52 PM Tom_L: that may have been on the sherline vise...
08:52 PM Tom_L: i never use it now
08:54 PM Tom_L: https://www.youtube.com/watch?v=lNJXA3Qv2i4
10:09 PM darkrose: rue_mohr: yeah, Taig lathe is boxed up, as is my 3d printer
10:10 PM Tom_L: hard to use in a box
10:10 PM rue_mohr: needs a home, along with its owner
10:11 PM * darkrose nods
10:15 PM aandrew: my 8yo has been trying to take over my office
10:16 PM aandrew: he erased my whiteboard which had my ridiculous password for one of y contracts (thankfully I have a pic of it) and he's used my cork board to pin up "among us" activities
10:16 PM aandrew: and all my small screwdriver bits have been scattered to the wind
10:18 PM Tom_L: when my youngest was younger i got him a handfull of hand tools because he liked to do things with mine
10:18 PM aandrew: oh yeah been through that. now he's wanting more :-)
10:18 PM Tom_L: as the weeks passed things started falling apart like door hinges etc
10:18 PM aandrew: the older one is all about making things, the 8yo is all about destroying things
10:18 PM aandrew: hahahaha
10:19 PM Tom_L: so we also learned how to re'assemble things too
10:20 PM aandrew: never had the door hinges go, but I came upon a wireless mouse which was not originally wireless, all of my flux remover is gone, and I've had to threaten them with violent bodily harm if they touch my black tape
10:25 PM rue_shop1: that machine wasn't technically made for milling metal, iirc
10:26 PM Tom_L: what sort of feedrate do you get with it?
10:29 PM rue_shop1: low
10:29 PM rue_shop1: top speed is something like 3ipm
10:29 PM rue_shop1: I'm gradually replacing the motors with ones I can use with new drivers
10:29 PM Tom_L: i ran the sherline pretty slow
10:30 PM rue_shop1: and I found all the source, I can change the signalling now
10:31 PM Tom_L: the one with the buffer issue?
10:34 PM rue_shop1: ?
10:34 PM rue_shop1: I found the source to the orig cnc machine
10:34 PM rue_shop1: its all dos code
10:35 PM rue_shop1: it uses 2 parallel ports
10:35 PM Tom_L: :)
10:35 PM rue_shop1: runs the 4 motor channels individually
10:35 PM Tom_L: dos is hard to beat
10:35 PM aandrew: it's too bad so much dos software was written to write directly to the lpt hardware
10:35 PM aandrew: I mean I remember exactly how great it was to just talk to the hardware directly
10:35 PM aandrew: but it sure does suck now
10:35 PM rue_shop1: I'm gonna change it up to grbl, but I have a heap of legacy software to "support"
10:37 PM rue_shop1: ok ok ok, big test on my stm32 DMA wave table...
10:37 PM rue_shop1: OMG it works!
10:37 PM rue_shop1: sweeeeet
10:38 PM rue_shop1: and that stm32 clock is unstable as all hell!
10:38 PM aandrew: actually I have a really neat URL relating to that
10:38 PM aandrew: when I was doing IEEE1588 with STM32
10:40 PM rue_shop1: wholy!!!
10:40 PM rue_shop1: its all over the map!
10:40 PM Tom_L: why so unstable?
10:41 PM rue_shop1: oh oh wait, it'll be cause its control by the ADC
10:41 PM rue_shop1: hah
10:42 PM aandrew: bah I can't find it
10:53 PM rue_shop1: this is awesome!
11:06 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180587.jpg
11:06 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180589.jpg
11:37 PM aandrew: well, that is a bit of an ego boost. I can spit out about 400 lines of C and it compiles witohout even a warning. Whether it's correct or not is another matter
11:40 PM rue_mohr: :)