#garfield Logs
Apr 26 2025
#garfield Calendar
12:15 AM rue_mohr: 10pm and I'm tired wtf
01:10 AM rue_mohr: Sample rate: 400.000000
01:10 AM rue_mohr: Buffer size: 512.000000
01:10 AM rue_mohr: Resolution: 0.781250
01:10 AM rue_mohr: Bins: 256.000000
01:10 AM rue_mohr: ok
01:11 AM rue_mohr: why do you think a 1725 rpm motor might be detected at 1500 rpm?
01:11 AM rue_mohr: odd
01:11 AM rue_mohr: the bins dont go to that freq
01:11 AM rifraf: not sure, thats why i am trying to get him to test qith a hdd or something known
01:12 AM rue_mohr: an fft, given those specs, runs from .39Hz to 199.61Hz
01:13 AM rue_mohr: I wonder if your inserting fake samples
01:14 AM rifraf: yeap, and using between 0.4 and 66 at moment
01:14 AM rifraf: harmonics, but its not really a harmonic value
01:14 AM rue_mohr: with 512samples, at 4khz, you get
01:15 AM rue_mohr: Sample rate: 4000.000000
01:15 AM rue_mohr: Buffer size: 512.000000
01:15 AM rue_mohr: Resolution: 7.812500
01:15 AM rue_mohr: Bins: 256.000000
01:15 AM rue_mohr: Bin 190 Fc= 1484.375 Fl= 1480.469 Fh= 1488.281
01:15 AM rue_mohr: Bin 191 Fc= 1492.188 Fl= 1488.281 Fh= 1496.094
01:15 AM rue_mohr: Bin 192 Fc= 1500.000 Fl= 1496.094 Fh= 1503.906
01:15 AM rue_mohr: Bin 193 Fc= 1507.812 Fl= 1503.906 Fh= 1511.719
01:15 AM rue_mohr: Bin 194 Fc= 1515.625 Fl= 1511.719 Fh= 1519.531
01:15 AM rue_mohr: Bin 195 Fc= 1523.438 Fl= 1519.531 Fh= 1527.344
01:15 AM rue_mohr: so, the resolution seems fine, 1500 is a legit bin
01:16 AM rue_mohr: Bin 219 Fc= 1710.938 Fl= 1707.031 Fh= 1714.844
01:16 AM rue_mohr: Bin 220 Fc= 1718.750 Fl= 1714.844 Fh= 1722.656
01:16 AM rue_mohr: Bin 221 Fc= 1726.562 Fl= 1722.656 Fh= 1730.469
01:16 AM rue_mohr: you should get a peak on 1 of those bins
01:16 AM rue_mohr: specifically 221 :]
01:17 AM rifraf: want some reall accelerometer data tp play with?
01:17 AM rue_mohr: if you give me a buffer, I could tell you what I see
01:18 AM rue_mohr: I should be able to write up my program to do a fft on it
01:19 AM rue_mohr: it been a while since I actually WROTE an FFT, but the programs I made are supposed to do it for me
01:20 AM rifraf: i can give you timestamped csv files with time x y z at around 400 hz
01:21 AM rue_mohr: around?
01:21 AM rifraf: i made an app that can read them and do fft with em on the phone
01:21 AM rue_mohr: well, it needs to be pretty accurate sample timing, thats important
01:22 AM rifraf: yes, sampling at max rate, so they can be at different intervals, thats why time stamped to 00:00.000 seconds
01:22 AM rue_mohr: but, at 400Hz, you cant get more than about 200Hz range
01:22 AM rue_mohr: so
01:22 AM rifraf: yes
01:22 AM rue_mohr: are you using an interpolator to fix the timing?
01:23 AM rifraf: i use an interfox to fix it
01:23 AM rue_mohr: .... and upsample to 4khz...
01:23 AM rue_mohr: "interfox" sounds like an interpolator
01:23 AM rifraf: ith low pass and high pass noise filters
01:24 AM rifraf: \don't you think the graphs are pretty darn nice?
01:24 AM rue_mohr: filters are stupid things, but what high and low cutoff freqs? (er, you can adjust cant you..)
01:24 AM rue_mohr: yea, but your freq should be dead on
01:24 AM rue_mohr: well, pretty close
01:24 AM rifraf: yes is hard when not much vibration and slow rpm spinning
01:24 AM rifraf: you should try
01:25 AM rue_mohr: you should also be able to filter out the peak freqs from the fft and reonstruct a sample to just do zero crossing with
01:25 AM rifraf: oh thats right you are stuck in 1994
01:25 AM rue_mohr: :] I'll ahve you know its 1984
01:25 AM rue_mohr: wait,... whats the song?
01:25 AM rifraf: maybe you can test if i put on an 8088 uc
01:26 AM rue_mohr: it could do it, no problem
01:26 AM rifraf: stuff these popular android things
01:26 AM rue_mohr: well, your supersampling and interpolating would be a slowdown
01:26 AM rifraf: yes on a phone much faster than the mega32
01:27 AM rue_mohr: esp if is a poly approximation and not just linear
01:27 AM rifraf: but i am doing basically the same i did with python
01:27 AM rue_mohr: doesn't take a phone to to fft
01:27 AM rifraf: i know
01:28 AM rue_mohr: https://www.youtube.com/watch?v=td7jzhWz-B0
01:28 AM rue_mohr: I should have included the audio :/
01:29 AM rifraf: it has audio
01:29 AM rue_mohr: the audio in the fft...
01:29 AM rifraf: anyway, cool, but not as cool as a phone app
01:30 AM rue_mohr: yep, throw away all the tech, a new phone just came out!
01:31 AM rifraf: hurry, you can get the old ones cheap, just get one
01:31 AM rue_mohr: hah, says rue who is using a ch32 as a serial adc
01:32 AM rue_mohr: oh damn, my buddy was by today, and I had SO many things to update him with I forgot to ask about the smartphones he's been throwing out and running over with cars (he hates smartphones)
01:32 AM rue_mohr: and smashing by using them as hammera
01:32 AM rifraf: :/
01:32 AM rue_mohr: and smashing by using them as hammers
01:33 AM rue_mohr: and table leg shims
01:33 AM rue_mohr: I think he puts his fist thru a monitor about every 9 months
01:33 AM rifraf: make him some spinning tops to calm him down
01:34 AM rue_shop4: he hung a led light fixture he hated by driving screws thru the middle of it into the cieling
01:34 AM rue_shop4: all I have to do is talk about soemthing like power converters and he instantly falls asleep
01:36 AM rue_shop4: he is currently 100% of my non-work social interaction
01:36 AM rue_shop4: I see him once about every week or two
01:39 AM rifraf: you know a normal 2 phase motor is about 1500rpm on 50hz, and about 1800 on 60hz
01:39 AM rifraf: maybe tom is on 50hz and does not know it
01:41 AM rue_shop4: heh, he's using a VFD, it outputs whatever its been programmed to
01:42 AM rue_shop4: and I think its from china
01:42 AM rue_shop4: so it might be set to 50Hz
01:42 AM rue_shop4: or is it his lathe
01:43 AM rifraf: his old lathe
01:46 AM rue_shop4: oh
01:47 AM rue_shop4: ok, the remote has the power supply on it, now where did I put my tx module
01:49 AM rue_shop4: ok, making a remote control link took me 3 weeks, does it work?....
01:49 AM rue_shop4: oh missing some wires
01:49 AM rue_shop4: oh no
01:49 AM rue_shop4: no just wries
02:01 AM rue_shop4: hahah wow
02:01 AM rue_shop4: the 2.4Ghz receiver on the robot causes its 5V regualtor to get really hot
02:01 AM rue_shop4: but, no date
02:01 AM rue_shop4: data
02:02 AM rue_shop4: I REALLY REALLY HATE wireless
02:11 AM rue_shop4: huh, after weeks of trying to come up with a battery powered supply for the remote, the wireless modules that I had tested and working stopped working
02:12 AM rue_shop4: thats frustrating
02:12 AM rue_shop4: now I get to start all over again
02:13 AM rue_shop4: no time for making tops rifraf
02:13 AM rue_shop4: but if you stay on the tops thing for a few years, I will get time
02:16 AM rue_shop4: midnight
02:16 AM rue_shop4: ok, two tested serial modules, working
02:20 AM rue_shop4: you see rif, this thing I'm doing, should be easy
02:20 AM rue_shop4: it should be quick
02:20 AM rue_shop4: and its not wroking for me worth *****
02:20 AM rue_shop4: and, I'm trying to find out why this happens to me
02:20 AM rue_shop4: I have a lot of things I want to be doing
02:20 AM rue_shop4: some of them are pointless
02:20 AM rue_shop4: but nothing is working for me
02:21 AM rue_shop4: and I have nobody to talk to about it
02:21 AM rue_shop4: like really sit and point with
02:21 AM rue_shop4: the 1 person I do have I see once every week or two and he falls asleep
02:21 AM rue_shop4: even tho he's interetsed
02:28 AM rue_shop4: their both talking fine now
02:28 AM rue_shop4: wtf
02:28 AM rue_shop4: this is why I need to be a robot
02:28 AM rue_shop4: I'm the only person there to talk to
02:29 AM rue_shop4: 25 years of being on irc, and like 8 of social media
02:29 AM rue_shop4: I still got nobody during 99% of the day to talk to but me
02:32 AM rue_shop4: hahaha
02:32 AM rue_shop4: damnit
02:32 AM rue_shop4: my issue is *TINY* distractions
02:32 AM rue_shop4: I TRIED to not let the cat bother me and still made a mistake
02:33 AM rue_shop4: next time I'm locking the cat in the house right away
02:33 AM rue_shop4: ok
02:33 AM rue_shop4: ok
05:13 AM rifraf: 7200 rpm drive now measures 7202, and 5900 rpm drive 5903, i can live with that, much better resolution now
08:48 AM Tom_L: rifraf, did you upload another build?
08:49 AM rifraf: i will before i crash out, is stable, but setting page a mess, am redoing it
08:49 AM Tom_L: ok i'll grab it when you say it's there
08:51 AM rifraf: is there now, same topspin.apk
08:53 AM Tom_L: want a motor test before you go?
08:53 AM rifraf: sure
08:53 AM Tom_L: gimme 5
08:54 AM Tom_L: settings are a mess
08:55 AM rifraf: stay out of there
08:56 AM rifraf: making a top designer, will change as yu change stuff, colours etc, show you cog
09:00 AM Tom_L: http://tom-itx.no-ip.biz:443/~webpage/rifraf/lathe_rpm3.jpg
09:00 AM Tom_L: it hit 17xx once but jumped around quite a bit
09:00 AM Tom_L: let it run a bit longer this round
09:00 AM Tom_L: the spike is where i lifted the phone off the motor
09:01 AM rifraf: looks a bit closer
09:01 AM Tom_L: yep
09:01 AM rifraf: try some spins
09:01 AM Tom_L: gotta mow before it rains
09:01 AM Tom_L: no time
09:01 AM rifraf: k
11:34 AM aandrew: https://www.instagram.com/reel/DHk8oYVNJbK/
11:34 AM aandrew: ok that's actually pretty cool
11:34 AM aandrew: coffee machine sized CNC
11:35 AM aandrew: https://www.youtube.com/watch?v=2WvTH_7BRO0 is a better video but the first is the auto tool changer
11:36 AM aandrew: actually https://www.youtube.com/watch?v=NU6N3Q2v3d8
11:36 AM aandrew: bet that thing is $$$$
11:56 AM aandrew: https://www.youtube.com/watch?v=bRY8N5l5l3c interesting video on how to NOT make a 5 axis cnc. dude's not an engineer, more kind of self taught, wonder what you guys think of some of his rules of thumb
12:05 PM aandrew: https://www.youtube.com/watch?v=bRY8N5l5l3c&lc=Ugw1-RFXNhH0C-r9csd4AaABAg great comment
12:12 PM rue_mohr: I wonder where my machine is at
12:13 PM rue_mohr: I'm heavy, but I'm using a 50:1 to a vacuum cleaner motor, which has a pretty light armature
12:15 PM rue_mohr: thanks aandrew
12:15 PM rue_mohr: I'm finding ali sort of useless for components
12:16 PM rue_mohr: I'm starting to turn to lcsc, but I'v not fired in an order yet
01:30 PM aandrew: I've ordered from LCSC a couple of times -- very professional, shipped fast, everything packaged appropriately
01:30 PM aandrew: I don't much like their product search but it's manageable
01:30 PM aandrew: and yes ali for *components* is a crapshoot, never know what you're going to get
01:31 PM aandrew: I did get my apple authentication ICs though, I have to build a little breakout for them and play
01:31 PM aandrew: I really want to get wireless carplay working with my own hardware and replace the double-din radio in my car
01:33 PM aandrew: the problem is that my car has the "pro" audio (I bought it intentionally) and the amp is 100% propretary so you can't just swap out the factory radio with an aftermarket one. I have to spend some time futzing with the controls and mapping CAN messages. so far I've been 100% unsuccessful in finding any documentation online about it
01:33 PM aandrew: I don't even care about EQ/etc but volume control is done over CAN
01:33 PM aandrew: I could swap out the amp but that feels like giving up
01:34 PM aandrew: ideally I'd take the RNS510 radio and gut it entirely, using the faceplate and rear panel only
02:11 PM aandrew_ is now known as aandrew
02:35 PM rue_mohr: no, product search is a falldown
02:36 PM aandrew: wtf
02:36 PM aandrew: https://youtu.be/-RaHk6ckrEI?t=600
02:36 PM aandrew: you can thread with a mill?!
02:36 PM rue_mohr: I'm trying to find comparartors with internal references and they dont have a 'features' column I can pick out by
02:36 PM rue_mohr: aandrew, yea, tom does it
02:36 PM aandrew: yeah best soution for that I've found is to use digikey/mouser and then try to find something similar on lcsc
02:37 PM aandrew: not ideal but better than nothing
02:37 PM rue_mohr: well, there is a new dimension
02:37 PM rue_mohr: chineese chips
02:37 PM rue_mohr: so, I'm looking for power converters, cheap
02:37 PM rue_mohr: and there are a HUGE number of chineese chips
02:38 PM rue_mohr: that dont turn up at all in digikey, but if your lucky they acually posted a pdf somewehre
02:38 PM rue_mohr: in my lcsc cart right now
02:38 PM rue_mohr: TP74LVC2G14S6
02:38 PM rue_mohr: S15V06S
02:38 PM rue_mohr: SN6501DBVR
02:38 PM rue_mohr: TLV77133PDBVR
02:38 PM rue_mohr: MMDT3906
02:39 PM rue_mohr: COS3201TR
02:39 PM rue_mohr: GS8706-TR
02:39 PM rue_mohr: totally not backup up my cart on irc right now
02:39 PM aandrew: that dude has some really dialled in 3d printers, wow
02:39 PM rue_mohr: yea, I have to rework all my 3d printers and I just dont have the energy
02:39 PM aandrew: yeah digikey/mouser then over to LCSC completely misses the chinese mfgs
02:40 PM rue_mohr: so, those are all parts to make various power converters later
02:40 PM rue_mohr: the 6501 is what I really want, but ouch $$$
02:40 PM rue_mohr: 50c ea
02:40 PM rue_mohr: I cant find a china equiv
02:41 PM rue_mohr: my right shoulder has been messed up for a few days and its getting annoying
02:42 PM rue_mohr: not sure whats up, its like it need a crack, but wont
02:42 PM rue_mohr: super awesome sunny day
02:42 PM rue_mohr: it seems that if a Comparator comes in a 6+ pin package, its got a ref in it
02:46 PM aandrew: it was literally pouring rain here like I haven't seen before but it's stopped now, still overcast
02:47 PM aandrew: been cool all week, not like california at all
03:01 PM rue_mohr: I'm still frustrated I could not get a 1.5V boost converter to output 3.3V at 80mA
03:02 PM rue_mohr: granted some of the batteries are a bit dead, but not down to 1V or anything
03:02 PM aandrew: Rue_mohr: https://x.com/ruenahcmohr/status/1916003748348104785?s=46&t=5LPGvbdUzMRL0qV1ATLLSA
03:03 PM aandrew: Isn’t that an off the shelf buck regulator module?
03:04 PM rue_mohr: I tried a few things and gave up
03:04 PM rue_mohr: yes
03:04 PM Tom_L: aandrew, yes you can threadmill
03:04 PM aandrew: Gotcha
03:04 PM Tom_L: i've done it
03:04 PM rue_mohr: so "battery powered 3.3V supply, 80mA capable"
03:05 PM rue_mohr: so, you just use li-ion as a 'goto' cause you expect a rechargable
03:05 PM rue_mohr: but, thats buckboost, and nothing worked
03:05 PM rue_mohr: so I went to 1.5V alkaline cell, (just boost, so easy right?) no, more failure
03:06 PM rue_mohr: so, screw it, 9V with linear regulator
03:06 PM rue_mohr: again, failure
03:06 PM rue_mohr: so, screw it, 9V with dc-dc buck module
03:06 PM rue_mohr: and that worked
03:06 PM rue_mohr: it took me about 2 weeks in all
03:06 PM rue_mohr: the question is, why did it take me so long
03:07 PM Tom_L: aandrew, http://tom-itx.no-ip.biz:443/~webpage/cnc/thread_mills/Thread_mill3.jpg
03:07 PM rue_mohr: I think I tried too hard on each method
03:07 PM Tom_L: single point are more versatile but multipoint are faster in that you only need a couple helix turns
03:07 PM rue_mohr: but I'm also noticing that I can get easily distracted and mess up a test/method
03:08 PM rue_mohr: I did have some other solutions that worked
03:08 PM Tom_L: https://onlinecarbide.com/thread-mills/un/d
03:09 PM Tom_L: same as mine only multi point
03:09 PM Tom_L: still cut a helix just fewer turns
03:13 PM Tom_L: tip: internal threads start at the bottom and go up where external threads start at the top and go down
03:14 PM Tom_L: he takes some pretty light cuts
03:16 PM Tom_L: cute project
03:17 PM Tom_L: wonder if his software can't interpolate an arc since he did all them in line segments
08:12 PM aandrew: Tom_L: that is cool, in hindsight it makes perfect sense but it was like holy shit for me to hear about it
08:14 PM aandrew: that'd be some pretty crazy control to spin the tool to cut the thread and also move the tool to cut a continuous thread
08:16 PM aandrew: I kind of gave up on buck-boost becuase a lithium cell drained to 3V is dead and that's also a reasonable-ish stopping point for 3V logic
08:18 PM aandrew: https://smallweb.run/
08:18 PM aandrew: not sure if you guys would be interested in that
08:20 PM aandrew: I found http://microblocks.fun yesterday as a "gateway" to getting kids into physical/embedded programming, most of the others I found either force you to use their hardware, aren't "live" (where changing the program on the computer instantly changes it on the device and you can see variables/inputs on the hardware on your screen in realtime), don't support wireless development (super important for
08:20 PM aandrew: mobile robots) or didn't support scratch as the "intro" to programming
08:23 PM aandrew: tiny dev team too but the "virtual machine" that's actually running on the embedded device is kind of neat
08:25 PM aandrew: I was on a (very) short contract with the jakdak (pxt) people but that's where I discovered I fucking hate typescript so it didn't work out very well: https://github.com/microsoft/pxt
08:33 PM aandrew: microblocks doesn't have a path to micropython but that's ok, by the time the kids start needing that they'll be more comfortable with general embedded concepts
08:35 PM Tom_L: aandrew, https://www.youtube.com/watch?v=JkAAWT7Nxd8
08:37 PM aandrew: so it's identical in concept to making threads on a lathe, except in this case the tool is both spinning and cutting deeper and deeper threads instead of the tool moving linearly and the workpiece spinning
08:38 PM Tom_L: helix path
08:38 PM Tom_L: typically a multi pass path
08:39 PM aandrew: right
08:39 PM Tom_L: it takes a 'set' of tools to make a range of threads due to the nature of the thread geometry
08:41 PM aandrew: right I understand
08:41 PM aandrew: lol
08:41 PM aandrew: "Hardware eventually fails. Software eventually works"
08:42 PM Tom_L: there are also form tools that don't actually cut the thread but form it
08:42 PM Tom_L: probably more common in external threads
08:45 PM aandrew: ... form? like squeeze/compress?
08:45 PM Tom_L: https://www.youtube.com/watch?v=Q9DlNs01N_A
08:45 PM Tom_L: yes
08:46 PM Tom_L: i've done external thread rolling
08:47 PM Tom_L: the holder in that video is a bit more complicated
08:47 PM Tom_L: the one i used was a pair of 2 rollers 180 deg apart across the material
08:50 PM Tom_L: roll threads are stronger
08:58 PM aandrew: wow that's pretty cool
08:59 PM Tom_L: those guys put out alot of good videos... sometimes a bit agressive
08:59 PM Tom_L: there are also single roll 'bump' rolls
09:00 PM Tom_L: or knurls