#garfield Logs
May 08 2021
#garfield Calendar
12:02 AM rue_shop1: think I can get the esp32 composite to work?
12:09 AM rue_mohr: I think the root is here
12:09 AM rue_mohr: https://github.com/rossumur/esp_8_bit
12:09 AM rue_mohr: https://github.com/Roger-random/esp_8_bit
12:09 AM rue_mohr: buyt
12:09 AM rue_mohr: but
12:12 AM rue_shop1: I see the problem here
12:12 AM rue_shop1: I dont have esp32
12:12 AM rue_shop1: I have esp8266
12:13 AM rue_shop1: ok
12:37 AM rue_mohr: huh, an esp32 is $10
11:56 AM Tom_L: cutters should be on the mail truck today
12:04 PM rue_mohr: nice
12:04 PM rue_mohr: i had a tracked package go missing eh?
12:04 PM rue_mohr: they can track it to the mail box set
12:04 PM rue_mohr: must have put it in the wrong box
12:05 PM rue_mohr: and my neighbour isn't returning it....
12:06 PM rue_mohr: so polprog last night I learned about unity gain stability on an amplifier
12:06 PM rue_mohr: says I need to learn more about phase margin
12:13 PM rue_mohr: since when did klingon get removed from google translate! >:\
12:15 PM Tom_L: heh
12:15 PM Tom_L: maybe they were getting too many replies from far away
12:23 PM polprog: rue_mohr: oh neat, were learning about that this semester
12:23 PM polprog: i think so
12:23 PM rue_mohr: lvdt?
12:23 PM rue_mohr: or unity gain stability and phase margins?
12:52 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/cutters/60deg_3flute1.jpg
12:52 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/cutters/60deg_3flute2.jpg
12:56 PM rue_mohr: wow, thats high pitch!
01:03 PM Tom_L: hopefully alot smoother finish
05:32 PM rue_mohr: me and ma went into the woods and got lots more plants for the garden!
05:33 PM Tom_L: nice
05:33 PM Tom_L: like what?
05:33 PM rue_mohr: huckleberries, some cedar trees, and some foxglove
06:52 PM polprog: awesome
06:53 PM rue_mohr: sometimes it feels like I'm not getting anything done tho!
06:56 PM polprog: oh. every week for me
06:58 PM rue_mohr: back in 1993 I got a big graphics lcd, and I cant find it
06:58 PM rue_mohr: I think I could do it with the fpga
07:05 PM polprog: you could make it a proper z80 style machine with a TTX chip
07:05 PM rue_mohr: no, I'm throwing retro and official out the window
07:05 PM rue_mohr: did you get what I did with the function call system?
07:06 PM rue_mohr: I have an idea for a math/function lookup table
07:06 PM rue_mohr: paged rom, its crazy
07:07 PM rue_mohr: but I'm holding off installing new chips till the pin headers arrive from ali
07:07 PM rue_mohr: not lots of the orig vero pins left
07:08 PM rue_mohr: tho I have to rewrap a whole memory socket
07:08 PM rue_mohr: I suppose I could be doing that
07:08 PM rue_mohr: its right up againt needing to remap all the memory
07:09 PM rue_mohr: and I'm not looking forward to that
07:09 PM rue_mohr: I'v decided there is no point in doing the system as almost all ram with a bootloader to pull an image from serial rom
07:10 PM polprog: I kinda understand it but i dont know enough z80 to fully grok it
07:10 PM rue_mohr: there is an interrupt mode on the z80
07:11 PM rue_mohr: where, it reads a byte from the bus on the interrupt
07:11 PM rue_mohr: it uses the byte as the lsb of a 16 bit address for a vector lookup table, the MSB comes from a special register
07:12 PM rue_mohr: so I made a magic memory address
07:12 PM rue_mohr: when you write to it, it stores the value and triggers an interrupt
07:12 PM polprog: and returns the written value as address
07:13 PM rue_mohr: the hardware uses the byte you wrote to get an address for the interrupt
07:13 PM rue_mohr: I use it for system functions
07:13 PM polprog: :)
07:13 PM rue_mohr: so, like, putc
07:13 PM rue_mohr: you put your character in A and write the const for PUTC in the magic address
07:13 PM rue_mohr: which triggers the interrupt and calls putc
07:13 PM polprog: yeah
07:14 PM rue_mohr: its lots more efficient than calculating the adress from a table
07:14 PM polprog: it is pretty awesome
07:14 PM polprog: if you ask me
07:14 PM polprog: i tried making the GM tube tick today
07:14 PM polprog: but it doesnt
07:14 PM rue_mohr: it also eats the interrupt system :)
07:14 PM rue_mohr: GM?
07:14 PM polprog: geiger-muller
07:15 PM rue_mohr: oh
07:15 PM polprog: did i tell you im making a counter
07:15 PM polprog: among 15 other things...
07:15 PM rue_mohr: there was a comment back there I didn't understand the context of
07:15 PM rue_mohr: but that explains the high voltage supply
07:15 PM polprog: yes, it runs at 400v
07:15 PM rue_mohr: darkrose, any house savings left?
07:16 PM rue_mohr: polprog, I got one of those, the cap was backwards and it blew up when I turned it on
07:16 PM polprog: i want to go to the market tomorrow so i need to get up at 7...
07:16 PM rue_mohr: 8-| china
07:16 PM polprog: haha
07:16 PM polprog: imma grab something to drink and sleep
07:16 PM rue_mohr: gnight
07:16 PM polprog: wings gave me some tips for the jfet circuits
07:16 PM rue_mohr: hey doa 2 transistor vco :)
07:16 PM polprog: ill test them maybe tomorrow, i hope
07:17 PM polprog: catch you on the flip side till then :)
07:17 PM rue_mohr: gngiht
07:17 PM rue_mohr: heh, I'm trying to stay awake
07:19 PM aandrew: polprog: got some bananas?
07:27 PM darkrose: rue_mohr: nope, spent it all on chocolate
07:29 PM aandrew: darkrose: not the best investment but one I can certainly get behind
07:32 PM darkrose: :D
07:36 PM rue_shop1: :( oh
07:38 PM rue_shop2: my buddy spent his on pop
07:38 PM rue_shop2: he walked into the grocery store and bought the whole pallette, right after the guy had finished putting it out for a sale
07:38 PM rue_shop2: they were annoyed
07:39 PM rue_shop2: he made a fort at home from cases of pop
07:39 PM rue_shop2: in the living room
07:41 PM darkrose: heh
07:41 PM aandrew: rue_shop2: seems a poor decision, more becuse he probably could have got it cheaper by dealing with the distributor directly for a pallet
07:43 PM darkrose: current plan is to buy a block of land, pinch some shed space off the friend I'm staying with, and build some steam loco's to raise some more funds to owner-build a small place
07:50 PM rue_shop2: ok
07:58 PM aandrew: darkrose: is there much market for steam locomotives? I expect it's mostly historical preservation / recreation type stuff?
08:02 PM darkrose: yeah, model live steam in the garden is pretty popular
08:21 PM rue_shop2: I stripped two motors out of the next of the disabilty carts
08:22 PM rue_shop2: their frozen :/
08:22 PM rue_shop2: I may try pulsing them with some high current
08:22 PM rue_shop2: I dont think I can try to turn them harder than they can
08:22 PM aandrew: what kind of motors are they?
08:22 PM rue_shop2: DC
08:22 PM aandrew: regular PM brushed dc motors?
08:22 PM rue_shop2: right angle drive motors from a disability chair
08:23 PM rue_shop2: yup PM
08:23 PM aandrew: you've probably already thought of it, but can the gearhead be removed from the motor itself?
08:24 PM rue_shop2: if I can get away with not dissassembling it, I'm happy
08:27 PM aandrew: I was just thinking maybe its the gears and not the motors that are siezed
08:27 PM * darkrose has a couple of those motors lurking about in a drawer
08:28 PM rue_shop2: planning to use them on the cnc
08:28 PM rue_shop2: the gears have lash
08:28 PM rue_shop2: but
08:28 PM rue_shop2: if I use two motors, with one being a constant force against the other it'll take out the lash
08:30 PM aandrew: completely random question
08:30 PM aandrew: if you had to make timing belt pulleys (such as https://www.linearmotiontips.com/how-to-specify-pulleys-for-synchronous-belt-drives/) -- how would you approach that from a cylinder of aluminum?
08:31 PM rue_shop2: one or more?
08:31 PM aandrew: well one for now, this is just hypothetical
08:32 PM aandrew: I mean it seems you'd use both a mill and a lathe to accomplish it, probably with an indexing wheel
08:32 PM rue_shop2: I'd put a shaped cutter sideways in the lathe and use the carriage feed to scrape in the slots
08:32 PM aandrew: ok so pretty much exactly the same way you'd build a pinion gear
08:33 PM rue_shop2: I suppose
08:33 PM rue_shop2: never thought about that, have you seen my box of gears?
08:33 PM aandrew: no, it's probably 5x the size of mine :-)
08:34 PM aandrew: do you organize your gears by module or just in a big pile
08:34 PM rue_shop2: large tub thats overflowing with 5 small tubs as backup
08:34 PM rue_shop2: I seperated out the ones with angled teeth
08:34 PM rue_shop2: there are some bags with matched pitch
08:34 PM rue_shop2: but otherwise dogpile
08:34 PM aandrew: *nods*
08:35 PM aandrew: ali shipping is so ... random
08:35 PM rue_shop2: yup
08:35 PM rue_shop2: get this
08:35 PM rue_shop2: tracked package
08:35 PM rue_shop2: I didn't get it
08:35 PM rue_shop2: tracking says it got right up to my box set
08:35 PM rue_shop2: they must have put it in the wrong one
08:35 PM aandrew: arbitrary store, qty 1 of something weighing 10g: free shipping. qty 2 = $3, qty 3 = $9. can't go back to qty1 and get free, ahve to close the page and go there again
08:36 PM rue_shop2: I just reload it
08:36 PM aandrew: rue_shop2: yeah that happened to me and the arbitration process didn't sovle anything
08:36 PM rue_shop2: no it was DEFINITLY the local post office
08:36 PM rue_shop2: they even tracked it and know it was at the box
08:36 PM aandrew: and if you contact the store about the shipping price, they just say "sorry it's aour carrier" and you can't argue with them.
08:37 PM rue_shop2: you can aggragate tho
08:37 PM rue_shop2: there are aggragator businesses
08:37 PM aandrew: rue_shop2: and your reputation should allow you to easily retrieve that package from the wrong recipient
08:37 PM aandrew: I can't imagine there are too many people in your area who get the kind of stuff you do :-)
08:37 PM aandrew: rue_shop2: yeah you mentioned that last night, I won't go there
08:37 PM rue_shop2: composite to hdmi converter
08:38 PM rue_shop2: for playing with z80 video
08:45 PM aandrew: I got 4x of these: https://www.aliexpress.com/item/1005002093968109.html
08:46 PM rue_shop2: yea, the lcd I'd like to use takes hdmi
08:46 PM rue_shop2: and I need to work out how to generate a signal from the z80
08:46 PM rue_shop2: but an intermediate gpu seems like a good idea
08:46 PM rue_shop2: "draw line from 10,10 to 50,860
08:46 PM rue_shop2: "
08:47 PM Tom_L: been disecting my tool description file all evening
08:48 PM rue_shop1: ?
08:48 PM aandrew: rue_shop2: yes a high level display board makes a lot of sense
08:48 PM Tom_L: so i can edit the file with an editor instead of thru the program
08:48 PM rue_shop1: ah
08:48 PM Tom_L: had to figure out what all the vars did
08:54 PM rue_shop1: ;)
08:54 PM rue_shop1: ok, dc servos is what I should focus on
08:55 PM Tom_L: there are at least 3 sections of vars that all interact on this thing but it's getting clearer
08:55 PM rue_shop1: I have a hard time coming to terms mentall with how slow mechanics move to microcontrollers
08:56 PM Tom_L: not if you saw the machines my kid runs
08:56 PM Tom_L: would scare the living shit outta ya
08:56 PM rue_shop1: to the microcontrollers, its still all slow as hell
08:56 PM rue_shop1: but ya
08:57 PM Tom_L: cutting 200+ ipm or more
08:58 PM Tom_L: but your point is well taken
08:58 PM rue_shop1: I wanted to understand steppers better
08:58 PM rue_shop1: so I set up a jig
08:58 PM Tom_L: mine step at 40k steps per inch
08:59 PM rue_shop1: and was looking at the delay between turning on a coil and the armature starting to move
08:59 PM Tom_L: i remember that
08:59 PM rue_shop1: but I lost my numbers
08:59 PM rue_shop1: its still set up
09:06 PM rue_shop1: it takes over 1ms for the shaft to start moving after a step
09:31 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/steppertime.png
09:39 PM rue_shop1: ah I have a better test
09:43 PM rue_shop1: 350us
10:19 PM rue_shop1: wow, the reprap driver takes 46ms to settle
10:20 PM rue_shop1: it takes 300us to start
10:33 PM rue_shop1: er I did something wrong
10:33 PM rue_shop1: 42ms to settle on the step
10:34 PM rue_shop1: 232us to start moving
10:47 PM rue_shop1: hey
10:47 PM rue_shop1: thats odd
10:47 PM rue_shop1: microstep isn't microstepping
10:47 PM rue_shop1: at all
10:49 PM Tom_L: ok. 40 tools in the tool table now and lcnc's tool table updated to match
10:49 PM rue_shop1: ah, I didn't have the stepper driver tuned and it wasn't even close
10:49 PM Tom_L: and i learned how to manually edit the tool table
10:49 PM Tom_L: pita
10:50 PM rue_shop1: heh
10:50 PM Tom_L: it's got several sections i'm not even using
10:50 PM Tom_L: like material type etc
10:54 PM rue_mohr: wrong channel
10:54 PM rue_mohr: I thought those tables were the success to your feed rates
10:54 PM Tom_L: ?
10:54 PM Tom_L: well i'm using them on the cutters so yes/
10:54 PM Tom_L: ?
11:26 PM rue_mohr: hmm
11:32 PM rue_mohr: so, at 16Mhz, theres time for about 3712 instructions to start the motor turning