#garfield Logs
Aug 13 2020
#garfield Calendar
12:07 AM rue_mohr: ok
12:13 AM rue_mohr: so sliders, like mine
12:13 AM zhanx_workshop: that is the plan with pivots
12:13 AM rue_mohr: oh, the frame AND the heater on sliders?
12:13 AM rue_mohr: hmm
12:13 AM zhanx_workshop: yes
12:13 AM zhanx_workshop: this is the mini test while i wait on parts for other stuff
12:33 AM Tom_L: 0-10v
12:34 AM zhanx_workshop: for once the 3d printer is being nice
12:35 AM rue_mohr: did you see the seti mountian dish broke?
12:36 AM zhanx_workshop: https://www.theatlantic.com/science/archive/2020/08/arecibo-observatory-damage-seti/615214/
12:39 AM rue_mohr: it'll probably be a mess to try to get it the right shape again
12:39 AM zhanx_workshop: yep
09:02 AM rue_mohr: are you guys seeing this "killing of usps" ?
09:25 AM rue_mohr: morning
09:35 AM Tom_L: morning and no
09:48 AM rue_shop1: making pcb's for work today
09:48 AM rue_shop3: see how this goes
10:11 AM rue_shop1: ok apparently I forgot how to use that plotter :/
10:11 AM rue_shop1: haha
10:41 AM Tom_L: :)
10:41 AM Tom_L: took off today... fail
10:41 AM Tom_L: guy rescheduled
10:58 AM rue_shop1: this is the acid test
10:58 AM rue_shop1: can I etch boards faster than I can protoboard them
11:01 AM rue_shop1: heh, I'm plotting them faster than their etching
11:06 AM rue_shop1: first board etched
11:08 AM rue_shop1: 2nd board etched
11:12 AM rue_shop1: not sure if I was supposed to do 3 or 4
11:17 AM rue_shop1: 3rd board etched
11:18 AM rue_shop1: 4 is goal
11:19 AM rue_shop1: hope my design was right
11:22 AM rue_shop1: and thats number 4
11:23 AM rue_shop1: 1.5hrs from nothing to 4 etched... hmmmm
11:23 AM rue_shop1: not my best time
11:33 AM rue_shop1: "Why hasn't google fetched my email yet" "google has 1.5 billion email addresses to manage, it cannot do every one of them every minute. To demonstrate how big the number 1.5billion is, I shall quickly count to it"
11:35 AM rue_shop1: damn, the pen was a bit small, so the pads are small
11:52 AM Tom_L: you should have etched them all at once
11:57 AM rue_shop1: I know
12:00 PM Tom_L: do you heat the etchant?
12:00 PM rue_shop1: yup
12:00 PM rue_shop1: fishtank heater with the boost autotransformer (160V)
12:01 PM Tom_L: i used to heat the 2ltr bottle in hot water in the sink before i started
12:02 PM Tom_L: not even for that long
12:05 PM rue_shop1: hahaha
12:05 PM Tom_L: i saved that pulley page in my brouser but it won't go to it
12:05 PM rue_shop1: thought I'd checked this carefully enough
12:05 PM rue_shop1: the rectifier is a dip6 not dip8
12:05 PM Tom_L: if it edit it and copy the link from there it goes
12:07 PM Tom_L: you should get this copper before i decide to toss it out
12:08 PM rue_shop1: just not sure how
12:08 PM Tom_L: move closer?
12:10 PM rue_shop1: note sure I want to :S
12:11 PM rue_shop1: your country is messed
12:11 PM rue_shop1: not saying ours isn't, but were a ways behind ya
12:18 PM Tom_L: seems like the norm. we're used to it
12:18 PM Tom_L: at least we can get stuff shipped :D
12:18 PM Tom_L: so far...
12:48 PM rue_shop1: I didn't document two of the resistor values
12:49 PM rue_shop1: or I have a missing drawing
12:55 PM Tom_L: board salvageable?
12:56 PM Tom_L: good about smt, you can stick them just about anywhere
01:11 PM rue_shop1: yea itll be fine
01:53 PM rue_shop1: ok, 1 board done
01:53 PM rue_shop1: close enough
01:53 PM rue_shop1: in all honesty, the staff are disabling all these after the owner installs them
01:53 PM rue_shop1: so whatever
01:54 PM Tom_L: what's it for?
01:54 PM rue_shop1: its a door nazi
01:54 PM rue_shop1: non-disablable door alarm for doors the owner doesn't want anyone to use
01:54 PM rue_shop1: owner isn't on site
01:54 PM Tom_L: but they'll disable em anyway
01:55 PM rue_shop1: seagul manager
01:55 PM rue_shop1: flies in, ****** on everything, flies off
01:55 PM Tom_L: heh
01:56 PM Tom_L: i bet we have more canadian geese here than you do
01:56 PM Tom_L: they crap on everything
01:56 PM rue_shop1: ok, 3 more to make
01:56 PM rue_shop1: after lunch
01:58 PM Tom_L: the site i bookmarked a bit ago is gone now
02:01 PM Tom_L: found it in spanish
02:08 PM polprog: rue_shop1: im sure i saw some computer generated temp charts in ircjunk
02:10 PM polprog: oh, GAL ics came in
03:08 PM rue_shop1: my pcb fuse patterm part is off
03:09 PM rue_shop1: polprog, oh thats my i2c network
03:35 PM Tom_L: 3 mistakes and you're out!
03:36 PM rue_shop1: heh
03:36 PM rue_shop1: its gonna work out
03:36 PM rue_shop1: but question
03:36 PM rue_shop1: http://tom-itx.no-ip.biz:81/~tom-itx/irc/logs/%23garfield/2020-04-12.html
03:36 PM rue_shop1: that was the day of the origional build
03:37 PM rue_shop1: huh
03:38 PM rue_shop1: oh
03:38 PM rue_shop1: http://tom-itx.no-ip.biz:81/~tom-itx/irc/logs/%23garfield/2020-05-12.html
03:39 PM rue_shop1: if I didn't know better I'd say it hadn't happened
04:09 PM rue_shop1: ok, boards assembled
04:11 PM Tom_L: how does it alarm the owner?
04:12 PM rue_shop1: fire horn
04:12 PM rue_shop1: without the word fire on it
04:13 PM Tom_L: does it keep goin after the door is shut?
04:13 PM rue_shop1: I either just programmed 3 chips, or I programmed one of them twice
04:13 PM rue_shop1: until an employee uses their key to silence it
04:13 PM Tom_L: lovely
04:13 PM Tom_L: put the key switch right by the horn
04:19 PM rue_shop1: its all around the door
04:19 PM rue_shop1: one of the other electricians is setting up the wiring
04:19 PM rue_shop1: doorbell transformer, boxes, etc etc
04:21 PM rue_shop1: the circuit is just a little glue around a tiny13
04:29 PM rue_shop1: they dont work without the tiny13 plugged in
04:32 PM rue_shop1: ok, now onto mechanical mounting
04:38 PM Tom_L: got a fancy bullet proof box to put it all in?
04:41 PM rue_shop1: heh
04:41 PM rue_shop1: canada
04:49 PM rue_shop3: 1) nobody just carries guns
04:49 PM rue_shop3: 2) its impolite to shoot peoples stuff
04:49 PM rue_shop3: 3) I'm too polite to make it so they cant shoot if it they wanted to
04:50 PM rue_shop3: dear god, the random list on the jukebox ran dry
05:03 PM Tom_L: put another quarter in
05:08 PM rue_shop1: so it runs about 5.5 hrs when ya hit 'random'
05:08 PM rue_shop1: hmm
05:09 PM Tom_L: ok. i need a project
05:09 PM polprog: build the transistor tester.. ill have to redesign it to use a diff amplifier
05:09 PM polprog: and an active rectifier so I can use a regular galvanometer
05:10 PM polprog: ok, the ISA cardputer came in
05:10 PM polprog: or rather i went to pick it up from the self service
05:10 PM polprog: what a mayhem on the board. someone tried to desolder the bios and Disk on Chip, about 10 traces are cut
05:11 PM polprog: i need to build a buck conveter so i can power the raspberry with some battery packs i have
05:13 PM polprog: internet say its an AMD X5, 133MHz.
05:13 PM polprog: not bad. i expected a 486
05:14 PM rue_shop1: heh
05:14 PM rue_shop1: the amd 586 was terrible
05:15 PM rue_shop1: no math errors tho
05:21 PM polprog: this will be a bitch to fix up
05:21 PM polprog: i mean
05:21 PM polprog: rewarding
05:21 PM Tom_L: heh
05:22 PM polprog: https://polprog.net/rozne1/ircjunk/cardputer/carputer_carnage.jpg
05:22 PM polprog: https://polprog.net/rozne1/ircjunk/cardputer/cardputer_mainboard.jpg
05:22 PM polprog: https://polprog.net/rozne1/ircjunk/cardputer/carputer_ports.jpg
05:29 PM rue_shop1: I wonder if there was another problem that lead them to try to strip it down
05:30 PM rue_shop1: almost done
05:31 PM rue_shop3: *blink*
05:31 PM rue_shop3: waiting for spacers to print
05:31 PM polprog: probably wanted to sell the eproms
05:33 PM rue_shop1: I'm glad I didn't try to squeeze that into 4 hours
05:43 PM polprog: looks like it takes some award 486 bios. so ill try to find a bios image from a matching chipset..
05:45 PM rue_shop1: hmm, I have a number of awards in my eprom pile
05:49 PM polprog: i found a zip with what is a 486 bios for the chipset
05:49 PM polprog: but im not touching this today
05:50 PM polprog: i wonder if the jungle io card, that has a molex power connector, feeds that into the ISA connector
05:51 PM rue_shop1: got some sockets for it?
05:52 PM polprog: for what? ISA sockets or DIP sockets?
05:54 PM rue_shop1: the roms
05:56 PM polprog: yeah, i got them
05:56 PM polprog: whole tube of wide sockets
05:57 PM rue_shop3: ok
05:58 PM rue_shop3: I could have done it cheaper with some arduinos and a relay shield of some kind
05:58 PM rue_shop3: but I wouldn't have recieved them in time
05:59 PM polprog: what are you building? some building automation stuff?
05:59 PM rue_shop3: its a bunch of boards for door alarms at hardware stores
05:59 PM polprog: i left my temp logger running... 1 channel so far
05:59 PM rue_shop3: k
05:59 PM rue_shop3: lm75?
05:59 PM polprog: lm335
05:59 PM rue_shop3: analog
05:59 PM rue_shop3: ?
06:00 PM polprog: yeah, goes to MCP3002 10bit adc
06:00 PM polprog: spi
06:00 PM polprog: that goes to the raspberry
06:00 PM rue_shop3: huh
06:00 PM polprog: and then some python thrown together prints out the temp in deg C
06:00 PM polprog: those MCP3002 are freaking awesome. I have to buy more
06:00 PM rue_shop3: the photo looked like 2 transistors
06:00 PM polprog: they are the LM335s
06:01 PM rue_shop3: I wonder what the diff is between the lm35 and the 335
06:02 PM polprog: 0mV + 10mV/degC?
06:02 PM polprog: huh
06:02 PM polprog: yeha seems the diff is that 335, 235 and 135 do 10mV/Kelvin
06:02 PM polprog: so you can use them for negative stuff
06:02 PM rue_shop3: you know about the lm75, right?
06:02 PM polprog: interesting. ive never heard about the 35
06:03 PM rue_shop3: i2c
06:03 PM polprog: i see
06:03 PM rue_shop3: 3 bit configurable address
06:04 PM polprog: that would simplify the design even more
06:04 PM polprog: i got an aversion to i2c
06:04 PM polprog: it was always fiddly to get working
06:04 PM polprog: although the last tuner hacking night was pretty okay
06:05 PM rue_shop3: odd
06:05 PM rue_shop3: I use flurys library, rarely have issues
06:05 PM polprog: maybe i just have PTSD after the avr implementation
06:05 PM rue_shop3: I ported it to C
06:05 PM polprog: if-else chain in the ISR
06:05 PM polprog: i know. easier to bitbang than to use hardware
06:06 PM polprog: did you see the portable TV i fixed
06:10 PM rue_shop3: no
06:10 PM polprog: damn twitter
06:10 PM rue_shop3: did you see my port of flurrys software i2c?
06:10 PM rue_shop3: oh wait
06:10 PM rue_shop3: twitter, yea
06:10 PM polprog: i know it exists, and i may have seen it
06:11 PM rue_shop3: the nice square black one
06:11 PM rue_shop3: sometimes I forget from who I saw what :)
06:11 PM polprog: yeah, square with silver bezel
06:14 PM rue_shop3: so,
06:15 PM rue_shop3: that was frustrating today, I seem to have lost the sheet with the details on how I built the other door alarms
06:15 PM rue_shop3: I had a voltage dropout detector that I didn't have the info for the resistors on
06:17 PM rue_shop3: hmm
06:18 PM rue_shop3: if I use 20 turn pots on the power supply, then for 18V 5A each turn on the voltage is about 1V, and each turn on the current is 250mA
06:20 PM rue_shop3: I was looking at a pic of a reflective galvanometer today
06:20 PM rue_shop3: and I was thinking that it would be nice to do a really wide analog movement
06:25 PM polprog: what do you mean?
06:30 PM rue_shop3: something like a 20cm wide analog meter
06:30 PM rue_shop3: maybe based on a reflected laser beam
06:31 PM rue_shop3: about 1cm high
06:34 PM polprog: ahh
06:34 PM polprog: neat
06:34 PM polprog: hmm, so this jungle card is not feeding the power back into the isa bus
06:34 PM polprog: not good
06:35 PM polprog: id likw to use it to power the bus...
06:35 PM polprog: i guess ill have to jump it
06:35 PM polprog: since it will be the only power input
06:35 PM polprog: isa seems to also use -5 and -12.. hmm
06:36 PM polprog: maybe ill have to make a power card then
06:39 PM rue_mohr: yes and no
06:39 PM rue_mohr: the vga card might use it, likley nothing else
06:39 PM rue_mohr: and you might be able to find a vga card that doesn't need it
06:39 PM polprog: the com port drivers on the jungle card use -12 for sure
06:39 PM polprog: but i could leave that out
06:40 PM rue_mohr: might use +12 also
06:40 PM polprog: the cpu card has got 5V drivers with charge pumps
06:40 PM polprog: yeah but im thinkig about -5 and -12
06:40 PM polprog: that dont come over the 4 pin molex
06:40 PM rue_mohr: hmm
06:40 PM rue_mohr: character lcd
06:40 PM rue_mohr: hmmm
06:40 PM aandrew: well
06:41 PM rue_mohr: if I use a 40 character wide lcd
06:41 PM aandrew: I made a PCB for that airflow sensor, rue_mohr. boards came to day and I built it
06:41 PM rue_mohr: no, there are gaps
06:41 PM polprog: thats what i call the jungle card: https://polprog.net/rozne1/ircjunk/cardputer/IMG_8224.JPG
06:41 PM aandrew: used SOT563 parts for the sense transistors
06:41 PM aandrew: immediately smoked the one that is supposed to be 50C above ambient :-)
06:41 PM rue_mohr: oops
06:41 PM rue_mohr: 50c!
06:42 PM aandrew: thankfully I designed it in such a way that I can easily experiment with the transistors and with the original TO92 ones it works well
06:42 PM polprog: hey, i may get away with jumping +5 and +12 to the backplane via the jungle card :) trident seems to only use +5V
06:42 PM aandrew: so I think what I want to do with it is to scale it waaaaaay the fuck down and use a better comparator to maintain a much smaller VBE voltage differential (maybe 10mV instead of 100mV), and scale all the current down and see if I can't make it work with teeny tiny transistors
06:43 PM rue_mohr: 50c...
06:43 PM aandrew: I ordered two designs from JLCPCB, only the one was supposed to be 0.8mm thick, the other was supposed to be the usual 1.6
06:43 PM aandrew: they are both 0.8mm thick
06:43 PM rue_mohr: hmm
06:43 PM aandrew: rue_mohr: yeah, 100mV differential, -2mV/C
06:43 PM rue_mohr: I keep hearing about issues with them
06:44 PM aandrew: well their silkscreen is kind of shit, but the boards turned out perfect (just 2L designs this time)
06:44 PM aandrew: but with 5/5 trace/space and 8mil drills
06:44 PM aandrew: I consider that a decent test of the budget mfg
06:45 PM aandrew: I try to stick to 4/4 and 8mil on my "pro level" boards
06:45 PM rue_mohr: https://www.aliexpress.com/item/4000415652174.html
06:45 PM aandrew: so if they can hit 5/5 and 8mil that's pretty decent
06:45 PM rue_mohr: I'm trying to get ideas for a power supply interface
06:45 PM rue_mohr: https://www.aliexpress.com/item/4000938638452.html
06:46 PM rue_mohr: I really like analog meters, they show dynamic things better
06:47 PM aandrew: 10 of each 2L design cost me like US$35 shipped
06:47 PM rue_mohr: I just did 4 pcb's today
06:47 PM aandrew: that's 2L, leaded HASL, soldermask both sides, silkscreen both sides
06:47 PM aandrew: and I got it delivered in 7 days
06:47 PM rue_mohr: etched, drilled, assembled, tested, 7.5 hrs
06:48 PM rue_mohr: + a bit of loafing, I lost some design values I needed
06:48 PM aandrew: rue_mohr: nice. I've lost my appetite for making PCBs at home, maybe if I get a $4k mill that can do 5/5 and registration is good for 2 sides
06:50 PM rue_mohr: so
06:50 PM rue_mohr: what resolution for a meter on a power supply is reasonable
06:51 PM polprog: goodnight
06:51 PM rue_mohr: if I used an lcd, would 0.25mm pixels be ok?
06:51 PM rue_mohr: could I see more than that on an analog meter anyhow?
06:51 PM aandrew: https://imgur.com/a/GrC9o9I are the two designs
06:51 PM rue_mohr: neat
06:52 PM aandrew: $800 for a triple 30A supply?
06:52 PM aandrew: amazon has similar models much cheaper
06:54 PM rue_mohr: I'm looking at the design
06:56 PM rue_mohr: I'm quite attracted to analog meters
06:57 PM rue_mohr: but it looks like as long as its not a digit-based meter, I'm ok with digital
06:57 PM aandrew: I like analog meters when I'm trying to see what a circuit's doing. I like digital values when I want to know a specific value
06:57 PM rue_mohr: yea
06:57 PM aandrew: that's why I like Fluke meters so much, they're both
06:57 PM rue_mohr: I'd like a graphic lcd analog meter
06:57 PM rue_mohr: but with two wheels
06:58 PM rue_mohr: an outter one for course range and an inner one for accuracy
06:58 PM rue_mohr: but I dont think I can pull off the graphics
06:59 PM rue_mohr: but I'd like an analog meter thats like 1cm high and like 20cm wide
07:00 PM aandrew: interesting
07:01 PM aandrew: why couldn't you do the graphics?
07:01 PM rue_mohr: not aware of a screen that fits that
07:01 PM aandrew: stm32 has free gfx lib, throw a SPI TFT at it and spend the next three weeks tweaking the look
07:01 PM rue_mohr: the dual dial idea, sure, if I thought I could pull off the graphics
07:01 PM rue_mohr: , an stm32 might
07:02 PM rue_mohr: 2d rotations?
07:02 PM aandrew: yep
07:02 PM rue_mohr: I dont know if I solved the floating point issue
07:04 PM rue_mohr: I'd use regular analog meters and just build the supply, but I dont ahve any for voltage
07:04 PM rue_mohr: ordered, I'm pondering while stalling
07:06 PM rue_mohr: hey
07:06 PM rue_mohr: maybe I COULD use a laserjet assembly
07:06 PM rue_mohr: change the laser, and pulse it
07:07 PM rue_mohr: mechanical speeds are nothing to digital speeds
07:07 PM rue_mohr: so the pulse would not be a challange
07:15 PM aandrew: hm?
07:15 PM aandrew: draw the display with a laserjet assembly?
07:16 PM rue_shop1: I just need to pulse the laser at the right time
07:16 PM rue_mohr: onto the back of some (paper?)
07:18 PM aandrew: well laserjets are IR, but maybe you could excite come photochemically doped paper
07:19 PM rue_shop1: na, I'd just change the laser
09:29 PM zhanx_workshop: wow the whopping -5 psi almost with this compressor
10:26 PM rue_mohr: k
10:27 PM rue_mohr: so I took a laser sweep assembly from a printer
10:27 PM rue_mohr: swapped it for a red led laser
10:28 PM rue_mohr: and made it project against the back of some paper
10:28 PM rue_mohr: with some timing to render a little line
10:37 PM Tom_L: cool
11:14 PM zhanx_workshop: rue_mohr, i took apart a dead microwave, to cut and re use the case as a heater for the vacuum former
11:29 PM rue_mohr: ok
11:38 PM zhanx_workshop: microvave was 19x10 box will be 9.5" cube