#garfield Logs

Mar 18 2020

12:01 AM rue_mohr: so, the banks get bailed out with no repercussions, and all the people with credit cards are scarred for life....
12:06 AM rue_mohr: cause, the banks were not at fault for issuing all the people all the cards...
12:06 AM rue_mohr: "sure..."
09:58 AM polprog: let's get this printer cradle running back again
09:59 AM polprog: i could use it to turn the rudder on my boat thingy
10:22 AM polprog: EPSON SEIKO EM-462
10:23 AM polprog: 4 wires
10:23 AM polprog: id need two h bridges
10:23 AM polprog: i think i have an IC like that
10:23 AM polprog: lubrication done
10:23 AM polprog: motor reverse engineer'd (not original, i have to drill fitting holes
10:24 AM polprog: i just need to make some servo, limit switches and/or an indicator
10:24 AM polprog: i could just print a small stripe pattern and make the MCU count it
10:24 AM polprog: id like to make that
10:24 AM polprog: and use optical interrupt sensors. i happen to have two identical
10:44 AM Tom_L: pla may not be uv invisible
10:44 AM Tom_L: the slots may not pick up
11:16 AM polprog: what?
11:18 AM Tom_L: i could just print a small stripe pattern and make the MCU count it
11:18 AM Tom_L: pla may not be uv invisible
11:18 AM Tom_L: the slots may not pick up
11:19 AM polprog: i mean print on a paper sticker
11:19 AM polprog: im not sure if the sensors are IR or UV, i think IR
11:20 AM polprog: i may have to build a detector with an LDR.. or better a phototransistor if i have one
11:20 AM Tom_L: i found inkjet to be non uv but laser toner is
11:20 AM polprog: i have laser
11:21 AM polprog: im worried it might be too reflective
02:55 PM polprog: the sensor works great
03:00 PM Tom_L: yay
03:08 PM polprog: https://twitter.com/polprogpl/status/1240366081966997508
03:08 PM polprog: printed the grid (grid?) on sticker paper and attched it onto the cradle
03:08 PM polprog: also attached the sensor to the carriage with scotch tape, for now
03:14 PM Tom_L: find a dot matrix encoder strip
03:14 PM Tom_L: same idea only finer
03:52 PM polprog: i think i might have one
03:52 PM polprog: i know i had one from that very printer but i think i threw it away
03:52 PM polprog: 2mm is fine for now
03:52 PM polprog: this is just meant to move a lever
05:20 PM polprog: what's a good way to do 3v3-5V level shifting?
05:21 PM polprog: hmm, might actually not need taht
06:21 PM Tom_L: phillips makes a level converter
06:21 PM Tom_L: that or a resistor divider
06:21 PM rue_mohr: unidirectional or bidirectional?
06:21 PM Tom_L: the phillips chip i used was bidirectional
06:22 PM polprog: i misremembered. The stm32 is 5v compatible i think
06:22 PM Tom_L: i wouldn't bet on that
06:22 PM Tom_L: GTL2003PW
06:23 PM Tom_L: comes in all sorts of widths from 2 bit up
06:23 PM rue_mohr: some pins are, carefull
06:24 PM polprog: ok, i have this chart which seems to be right with the docs
06:24 PM Tom_L: mmm now they're saying it's not for new designs...
06:24 PM polprog: some are. some arent
06:24 PM polprog: good.
06:24 PM polprog: now to try get the daln uart_printf working
06:24 PM polprog: printf wont work unless i recompile newlib
06:24 PM polprog: idk if i ever have that
06:24 PM Tom_L: i probably still have a fair pile of them
06:26 PM rue_mohr: well, the only job scheduled for today was finished in 2 hours, so we took the day off to get supplies because 3/4 or the stores in town are closing up
06:41 PM Tom_L: drove around a bit and it's like a ghost town
06:49 PM rue_mohr: polprog, my usb floppy drives arrived
06:49 PM polprog: oh neat
06:49 PM polprog: i need to see whats with mine
06:49 PM polprog: the guy sent me an email with a link to the drivers
06:49 PM polprog: (gdb) bt
06:49 PM polprog: #0 blocking_handler () at ../../cm3/vector.c:103
06:49 PM polprog: #1 0xfffffffe in ?? ()
06:49 PM polprog: Backtrace stopped: previous frame identical to this frame (corrupt stack?)
06:49 PM polprog: stm32 dev is going well
06:49 PM rue_mohr: drivers? er no
06:49 PM polprog: ikr
06:49 PM polprog: these were for win 7
06:49 PM polprog: ;)
06:50 PM rue_mohr: still no
06:50 PM rue_mohr: its a mfm floppy drive...
06:52 PM Tom_L: and you need one why?
06:52 PM rue_mohr: I got two
06:52 PM Tom_L: and you need two why?
06:52 PM rue_mohr: for dos machines I cant transfer things otherwise without
06:52 PM Tom_L: on my dos box i dual boot nt4
06:53 PM Tom_L: so that works out ok
06:53 PM Tom_L: gotta reboot but transferring stuff is quick
06:53 PM polprog: rue_mohr: USB MFM floppy drive?
06:53 PM polprog: i mean he sent me a link to the driversfor win 7 saying "youll need these if you run win 7"
06:54 PM polprog: the drive is just a standard USB 1.44M floppy
06:54 PM rue_mohr: flopy drive emulator
06:54 PM Tom_L: i got a whole pile of floppies that are probably no good now
06:54 PM rue_mohr: usb 2 mfm
06:54 PM Tom_L: can you boot from it?
06:54 PM rue_mohr: actaully their probably fine
06:55 PM rue_mohr: I havn't used them yet
06:55 PM rue_mohr: Need to see how to set up the image
06:55 PM polprog: ah, so a gotek
06:55 PM Tom_L: then the bios needs to be able to boot from USB
06:55 PM rue_mohr: no
06:55 PM rue_mohr: it emulates a floppy drive
06:55 PM rue_mohr: its an mfm device
06:55 PM rue_mohr: you plug a usb key into the front of it
06:56 PM rue_mohr: https://www.aliexpress.com/item/32951693684.html?spm=a2g0s.9042311.0.0.27424c4dFQN461
06:58 PM Tom_L: so you can use a thumb drive on mfm?
06:58 PM rue_mohr: yea
06:58 PM rue_mohr: the buttons select which floppy to access
06:59 PM Tom_L: i see
06:59 PM rue_mohr: I think you can put 256 floppys on your usb stick
06:59 PM Tom_L: 720 or 1.4?
06:59 PM Tom_L: or 180
06:59 PM Tom_L: :)
06:59 PM rue_mohr: 1.4
07:23 PM polprog: got something like that in my amiga
07:23 PM polprog: ok.. so today i did the encoder strip "frontend", got stm32 dev setup
07:24 PM polprog: tomorrow: L238D, find out why some GPIOs dont work on the stm32
07:24 PM polprog: maybe i should download newer version of locm3
07:24 PM polprog: i wonder what did they change again...
07:25 PM polprog: rue_mohr: did you see my encoder strip?
07:26 PM Tom_L: did you set that up as quadrature?
07:26 PM Tom_L: probably not..
07:27 PM polprog: no, i was thinking about gray code but i dont have enough detectors
07:27 PM polprog: so its just two striped graticules, 2mm pitch and 10mm pitch
07:27 PM polprog: im using the 2mm one now
07:28 PM polprog: ill see if i can cut the leftover photointerrupter to make it a second detector for the 1cmm grid
07:28 PM polprog: or make something from a led and an ldr
07:28 PM polprog: gray code would be neat...
07:34 PM polprog: i have these horizontal strip lasers, i could just need several LDRs and it would be a multipoint detector
07:34 PM polprog: nighters
09:39 PM rue_mohr: yea, I saw your thing, I'd be interested to see more detail on how you set up the detector, I cant tell if its a pre-made module or not
10:54 PM rue_mohr: right ok
11:09 PM rue_mohr: starting to feel a bit lost