#garfield Logs
Dec 31 2020
#garfield Calendar
01:25 AM rue_mohr: ok, I'm abck from work
02:08 AM rue_shop2: hahaha
02:08 AM rue_shop2: that regulator baord I bought
02:08 AM rue_shop2: I got some voltage inverter chips from china and forgot
02:08 AM rue_shop2: they just need an external cap
02:08 AM rue_shop2: hahaah
03:00 AM rue_shop2: I love this
03:00 AM rue_shop2: EVERY time I need a motor driver it turns into this huge ordeal
03:02 AM rue_shop2: I dont want to use an L298 unless I have an extra 4V of supply I can afford to lose to the load
03:05 AM rue_shop2: oh, I have an LMD18200 and L6203 I can use
03:06 AM rue_shop2: ok, those should be fine
03:06 AM rue_shop2: its good, cause my fets, with fet drivers, and bias supply are not small
05:25 AM rue_shop2: only 3am, I'm ok
05:31 AM Tom_L: no it's 5 am
05:33 AM rue_shop2: seeing if I can fit up a gearbox as a servo
05:36 AM Tom_L: for the cnc?
05:36 AM rue_shop2: no
05:36 AM rue_shop2: I want to play with some loop controllers
05:37 AM rue_shop2: I need a geared motor on a pot
05:37 AM rue_shop2: I want something better than the ones I already have made
05:37 AM Tom_L: pot or encoder?
05:37 AM rue_shop2: pot
05:38 AM rue_shop2: I cant find a good price on pots from china with long shafts
05:38 AM rue_shop2: like 2"
05:38 AM Tom_L: you should already have a bazillion pots...
05:39 AM rue_shop2: yea, I have ones with short shafts
05:39 AM Tom_L: why does that matter?
05:40 AM rue_shop2: if I have a 2" shaft, I can use the pot as the rear bearing, with its shaft being the output
05:43 AM rue_shop2: it sure is nice to have the design files for the gearbox
07:44 AM rue_mohr: oh, we have a newyears countdown tonight
01:21 PM TerminalMoon: hey rue_mohr you home?
04:05 PM rue_mohr: yes
04:05 PM rue_mohr: oh I was supposed to come over
04:05 PM rue_mohr: I worked till 11pm last night
04:05 PM rue_mohr: your not up that late anyhow
04:15 PM TerminalMoon: no :{
04:16 PM TerminalMoon: come now
04:17 PM rue_mohr: I was working on things till like 5am
04:17 PM rue_mohr: woke up about an hour ago
04:26 PM aandrew: rue_mohr: why haven't you come up with a standard h-bridge fet module that you're happy with for all of your motor needs
04:27 PM aandrew: rather than reinventing it every time, and with judicious footprint management you could put anything from TO92s to TO220s on it
04:31 PM TerminalMoon: rue_mohr has a love for chaos. though he's in denial
04:34 PM rue_mohr: aandrew, I know eh?
04:35 PM rue_mohr: the KMD18200 and L6203 are awefull on RDSon
04:35 PM rue_mohr: 300m ohms
04:35 PM rue_mohr: I have not found a circuit I like for driving motors
04:35 PM rue_mohr: lots that work, but all too big
04:35 PM rue_mohr: so far the right chip doesn't seem to be out there
04:36 PM rue_mohr: they all perform awefull or cost too much
04:36 PM rue_mohr: even the L6203 is expensive
04:36 PM rue_mohr: what are they, like $4ea on ali?
04:37 PM rue_mohr: ah about $1.50
04:37 PM rue_mohr: still
04:39 PM Tom_L: just don't leave anything undone in 2020
04:42 PM rue_mohr: well the cat puked on the bed this morning, so I have a little bit of 2020 to finish putting up with
04:43 PM aandrew: I put 6x MC33926 on a board and fucked up the D1/D2#; I somehow though they were EN1/EN2# and I did via-in-pad so that was a pain to deal with
04:44 PM aandrew: https://imgur.com/oiOjozs was the board, https://imgur.com/WtPMbWl is what I had to do to each one of them, plus tacking on a 30AWG to the side of the LCC pins to strap them correctly
04:49 PM rue_mohr: L293 has a saturation voltage of about 1.5V for all transistors, so, your losing 3V off your supply
04:50 PM rue_mohr: not sure why imugr doesn't work on firefox
04:50 PM Tom_L: i got a tube of 18200 somewhere
04:51 PM rue_mohr: as long as I dont leave chromium running too long I'm ok
04:51 PM rue_mohr: Tom_L, !
04:51 PM rue_mohr: a tube!
04:51 PM Tom_L: several
04:51 PM Tom_L: dunno how many
04:52 PM Tom_L: did a 3971 board for maxbot
04:52 PM rue_mohr: aandrew,
04:52 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/maxbot/image024.jpg
04:52 PM Tom_L: not much to it
04:52 PM rue_mohr: ouch
04:52 PM Tom_L: ?
04:52 PM aandrew: rue_mohr: teh goog says could be filtering (reset caches on ublock origin for example) or perhaps a firefox profile issue
04:52 PM rue_mohr: Tom_L, oh smt!
04:53 PM aandrew: man you guys and your tiny pictures
04:53 PM aandrew: that looks nice
04:53 PM Tom_L: that was long ago
04:53 PM aandrew: Tom_L: was it scanned from film? :-)
04:53 PM Tom_L: not that long
04:53 PM Tom_L: but i do have some of those too
04:53 PM aandrew: the MC33926s were okay but they werent' stellar
04:54 PM Tom_L: i forgot what i used on the sumo bot
04:54 PM Tom_L: 754410
04:55 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/sumo_files/sumo_electronics_index.php
04:56 PM aandrew: 5A, 5-28V, PWMable, slew-rate control if you want it... but pricey ($4) and kind of big
04:56 PM aandrew: oooh project page for sumo, nice
04:56 PM aandrew: I like the large solid wheel design
04:56 PM Tom_L: that was a kit
04:57 PM aandrew: hahaha
04:57 PM aandrew: you've got a link to wormfood's baudrate calculator
04:57 PM aandrew: I hung out with that dude on irc for close to two decades
04:57 PM Tom_L: yup
04:57 PM aandrew: dude moved to china and promptly disappeared
04:57 PM Tom_L: i did for quite a while
04:57 PM Tom_L: he showed up every so often after that
04:58 PM aandrew: I imagine him drowning in chinese women, he was always talking about how his chinese gf kept bringing other women home to him
04:59 PM aandrew: oh that MC33926 had a nice feature: built in shunt; it gave an analog output that was 0.25% of the motor current so you could monitor it with an ADC
05:00 PM rue_mohr: I think he got ill
05:00 PM rue_mohr: I has someone contact me about his website and I didn't click before they dissapeared
05:00 PM Tom_L: too many women!
05:01 PM aandrew: rue_mohr: yeah I think so too; I *did* have a link to his dave-in-china or something website but cannot for the life of me find it anymroe
05:01 PM rue_mohr: they sounded really desperite to get me to help with something
05:01 PM rue_mohr: like I say, we didn't connect
05:01 PM rue_mohr: I have an old copy of his calcl on my site
05:02 PM rue_mohr: http://ruemohr.org/~ircjunk/avr/baudcalc/avrbaudcalc-1.0.8.php
05:02 PM rue_mohr: I once asked for a copy "incase anything happened to him"
05:02 PM rue_mohr: he said to only post it if something did
05:03 PM rue_mohr: there are some snapshots of the output of the new version all over the place
05:04 PM rue_mohr: that circuit I posted on twitter isn't awesome, but its small
05:04 PM rue_mohr: and can be A/B mode or PWM/DIR mode
05:11 PM rue_mohr: in a world of amazing smps fets, I dont know why this problem exists
05:15 PM rue_mohr: TB6612: RDSon = 0.5 ohms
05:15 PM rue_mohr: there are FET DRIVERS that do better than that
05:18 PM rue_mohr: MX1508: RDSon = 0.4 ohms
05:29 PM polprog: happy new year folks :)
05:30 PM Tom_L: :)
05:32 PM aandrew: szczęśliwego Nowego Roku
05:33 PM aandrew: rue_mohr: it is a solved problem, you've gotta stop trying to do it discretely. :-)
06:04 PM TerminalMoon: rue_mohr: come get yoiur gift!
06:09 PM rue_shop1: ok, I have ONE thing I want to do today, give me a hour or so
06:09 PM rue_shop1: aandrew, no, its not tho
06:09 PM rue_shop1: 0.3 ohms? 3V drop?
06:09 PM rue_shop1: no
06:09 PM rue_shop1: no no no
06:12 PM TerminalMoon: ok
06:29 PM rue_shop1: looking good so far
06:30 PM rue_shop1: when is the flipping shortest day of the year?
06:35 PM TerminalMoon: its come and gone!
06:35 PM TerminalMoon: twas the 22nd
06:36 PM rue_shop1: that good cause this is frustrating
06:36 PM rue_shop1: who the hell reversed the pinout of the 74ls02 when I wasn't looking?
06:41 PM rue_shop1: nice! ok, one more test!
06:49 PM rue_shop1: cool ok, down in a bit
06:49 PM rue_shop1: TerminalMoon,
06:50 PM rue_shop1: https://cubscoutideas.com/wp-content/uploads/2020/09/cub-scout-robot-hand-complete.jpg
06:50 PM rue_shop1: want to make a robotic hand with me?
06:50 PM rue_shop1: :)
06:51 PM TerminalMoon: well ascii only for me, but mavy
08:24 PM TerminalMoon: rue_shop1: How do i get my hands on a drill press?
08:25 PM TerminalMoon: a beefCake one
08:27 PM Tom_L: how beefcake?
08:27 PM TerminalMoon: 2hp would be sweet
08:28 PM Tom_L: got craigslist up there?
08:29 PM TerminalMoon: oh yeah
08:29 PM TerminalMoon: yes
08:30 PM rue_shop2: heh, you got rid of the last one :)
08:30 PM TerminalMoon: it was balls
08:30 PM rue_shop2: heh, I bet you didn't use it once
08:31 PM TerminalMoon: ok you got me
08:31 PM TerminalMoon: true
08:31 PM rue_shop2: prolly for the better, you still have all your fingers
08:31 PM TerminalMoon: :)
08:42 PM rue_shop2: heh
08:42 PM rue_shop2: sitting here in denial that a motor has to have a acceleration rate that no drive electronics can improve
08:46 PM polprog: aandrew: dziękuję :)
08:48 PM polprog: So im pretty confident if i feed that creative 5.25 bay some spdif and power ill get music on the headphone out
08:49 PM polprog: and then if i feed a sample clock i can use the dacs that deal with aux in 1, 2
08:58 PM rue_shop1: MX1508 is only up to 9.6V
09:15 PM Tom_L: rue_shop1, will see the new year in and probably the sunrise
09:15 PM rue_mohr: not gonna be here for countdown?
09:15 PM Tom_L: maybe but probably not yours
09:15 PM Tom_L: that's 2am
09:18 PM polprog: ill be seeing the sunrise for sure
09:19 PM polprog: 4:07, i stayed up all night long
09:19 PM Tom_L: silly kid
09:19 PM Tom_L: guess you can do that while you're young
09:27 PM rue_shop2: I was up till 6am yes.... today
09:29 PM polprog: dont really have a choice :)
10:15 PM rue_shop2: I'm sure I should have some L9110 around