#robotics Logs

Nov 22 2017

12:03 AM anonnumberanon: yeah it has a pll but pll is only used to multiply the frequency of an external clock input, which there is none on this board
12:06 AM Tom_L: no internal osc?
12:06 AM anonnumberanon: there is one, ofc, that's what I'm trying to find out, i was gonna buy this board but if the frequency is really low i may not
12:06 AM rue_shop3: ok
12:06 AM rue_shop3: the daemon recognizes the cable signals
12:06 AM Tom_L: hour delay on the return
12:06 AM anonnumberanon: i love this board for the spacing of the pins
12:06 AM Tom_L: nav computer went out
12:06 AM rue_shop3: nav?
12:06 AM Tom_L: flight navigational computer
12:06 AM rue_shop3: uh?
12:06 AM Tom_L: kinda hard to go anywhere without one
12:06 AM anonnumberanon: can be plugged into a breadboard, didn't have that niceness with arduino pro mini that's what i hated about them
12:06 AM rue_shop3: you alive, your trip go wrong?
12:06 AM Tom_L: no
12:06 AM Tom_L: good trip
12:06 AM rue_shop3: your back?
12:06 AM Tom_L: just now
12:06 AM rue_shop3: I just assumed you got borred and are playing on irc from afar
12:07 AM rue_shop3: yea, freking rifraf said the sea was "refreshing" it was freaking cold
12:08 AM rue_shop3: ocean whatever
01:13 AM rue_shop3: yay, the joystick is modified
01:20 AM anonnumberanon: dumping elf, god help me
01:21 AM anonnumberanon: you got a joystick?
01:22 AM rue_mohr: modified a 1982 gravis to be a serial controller for an rov
01:28 AM Jak_o_Shadows: rue, if you ever want that to pretend to be a usb joystick (god help you, i don't know why you would), I have code for that
01:30 AM anonnumberanon: that's some nice hardware
01:30 AM anonnumberanon: good job
01:31 AM rue_mohr: Jak_o_Shadows, na, I have some usb joysticks, the goal was to make up something that already puts out the codes that my rov controller takes in
01:31 AM Jak_o_Shadows: makes sense
01:31 AM rue_mohr: for now, I can cat /dev/customrovjoystick > /dev/rovcontroller
01:32 AM rue_mohr: mmm 2 hour power outage
01:32 AM rue_mohr: oh damn, I have to reset the shop clock AGAIN
01:33 AM rue_mohr: its an led billboard, the stupid thing saves the time before the outage and starts there when powered back up
01:33 AM rue_mohr: ???!?!?!
01:33 AM Jak_o_Shadows: ahahaha
01:33 AM Jak_o_Shadows: becuase that is ideal for clocks
01:34 AM rue_mohr: I'm gladually modifying the interface program for it, right now, you run it and it syncs the clock to the computer
01:35 AM anonnumberanon: have an actual timer in it for those cases :3
01:35 AM Jak_o_Shadows: How does it connect to the computer?
01:35 AM rue_mohr: it dosn't drift much between power failures
01:35 AM rue_mohr: serial cable
01:35 AM rue_mohr: RS232 serial...
01:36 AM Jak_o_Shadows: Fairo
01:36 AM rue_mohr: oh, I'm gonna relocate that computer... hmmm
01:36 AM rue_mohr: need to think about that
01:37 AM Jak_o_Shadows: I bought a zigbee clone type thing.
01:37 AM rue_mohr: maybe I can start into the rov tommorow
01:37 AM Jak_o_Shadows: If it's waht all the cool kids are using for home automation, it'll do for me
01:37 AM rue_mohr: clone type?
01:37 AM Jak_o_Shadows: (until I run CAN through the walls orseomthing)
01:37 AM Jak_o_Shadows: well, it's not an xbee
01:37 AM rue_mohr: I thought everyone was using esp8266 cause their cheap as snot
01:37 AM Jak_o_Shadows: Yeah, I dunno.
01:37 AM rue_mohr: even I got an esp8266
01:38 AM Jak_o_Shadows: The cheap home automation stuff I can get ahold of is zigbee based
01:38 AM rue_mohr: I even got it to do something
01:38 AM rue_mohr: oooh
01:38 AM rue_mohr: get one and make it a bridge
01:38 AM anonnumberanon: i love those things
01:38 AM anonnumberanon: was really fun to use
01:39 AM rue_mohr: I need to sit down and make one into a translarent serial bridge for this rov
01:39 AM rue_mohr: that comes later
01:39 AM Jak_o_Shadows: the cheap home automation stuff alreayd has a home module that is a wifi -> zigbee bridge
01:39 AM anonnumberanon: was using an nrf24l01 but needed better antenna after a while
01:39 AM rue_mohr: not sure what port I want to use for sudo serial port over network
01:39 AM rue_mohr: 23?
01:40 AM Jak_o_Shadows: Nah. Shove it over 1024?
01:40 AM Jak_o_Shadows: 9600?
01:40 AM rue_mohr: hah 9600
01:40 AM Jak_o_Shadows: yeah. I like the symmetry
01:40 AM rue_mohr: hmm hey, I wonder if I should be worrying about tcp vs udp
01:40 AM Jak_o_Shadows: I was wondering about that
01:41 AM rue_mohr: :S
01:41 AM rue_mohr: I made sure the firmware cant saturate the 9600
01:41 AM Jak_o_Shadows: Do UDP.
01:41 AM Jak_o_Shadows: Your protocol should handle drops anyway
01:41 AM rue_mohr: I have a state machine in the reciever, so lost bytes should come out ok
01:44 AM Jak_o_Shadows: exactly
01:45 AM rue_mohr: when I go wireless a em stop on loss of connection heartbeat might be a good idea
01:45 AM rue_mohr: not have it go driving off into the sunset on me
01:46 AM rue_mohr: "Lost connection, maintaining speed, farewell!"
01:47 AM rue_mohr: "Where is the rov?" "North, somewhere"
01:48 AM rue_mohr: hmm, back to another problem
01:48 AM rue_mohr: I need a way of quickly simulating huge numbers of interconnected event timers
01:48 AM rue_mohr: in the order of 100G of them
01:49 AM rue_mohr: but I can start small
01:50 AM rue_mohr: gnight
01:50 AM anonnumberanon: you want an int generator?
01:50 AM anonnumberanon: night
01:55 AM rue_bed: no, intervals
01:56 AM rue_bed: so, a node fires an event, which is connected to other nodes, that delay and fire an event
01:56 AM rue_bed: programmable delays, but, I'm not sure of the resolution either
02:14 AM Jak_o_Shadows: rue_bed, there is a matlab toolbox? SimEvent? I've read a report where they used that
03:55 PM SomeT: I am researching amazon kiva robot for a school project, can anyone help me find some more academic papers in relation to this robot please?
04:13 PM SpeedEvil: There may even be none.
04:14 PM SomeT: :(
04:17 PM orlock: SomeT: industrial materials handling robots?
04:24 PM SomeT: what do you mean?
04:25 PM orlock: SomeT: There's likely not that much public academic type research, unless theres some white papers - all the interesting stuff is probbly trade secrets
04:32 PM SomeT: yeah
04:32 PM SomeT: I am tring to find schematics on it
04:32 PM SomeT: there are many different patents on it
04:33 PM SomeT: I found this
04:33 PM SomeT: https://web.archive.org/web/20150319034532/http://spectrum.ieee.org/robotics/robotics-software/slideshow-how-kivas-robotic-warehouse-works
04:33 PM SomeT: hidden away
04:34 PM orlock: SomeT: yeah, good luck with that - its likely grounds for instant termination, providing that information without an NDA
04:34 PM orlock: are you just talking about physical/mechanical design>
04:34 PM orlock: as thats likely the boring bit
04:34 PM orlock: unless you are an ME
04:35 PM SomeT: like I wanna know what sensors it uses for example
04:35 PM SomeT: or how many motors
04:35 PM SomeT: nothing to in depth
04:36 PM orlock: it senses thow much blood remains on the floor from its human victims
04:36 PM orlock: if theres not enough fresh blood left to lubricate it's axles it must go and hunt again
04:37 PM orlock: You think all of amazon's "warehouse workers" are actually filling boxes?
04:39 PM SpeedEvil: http://robohub.org/meet-the-drone-that-already-delivers-your-packages-kiva-robot-teardown/
04:39 PM SpeedEvil: couple of years old now
04:40 PM SomeT: nice one thankls
04:44 PM SpeedEvil: As a general point, the robots design is uninteresting.
04:44 PM SpeedEvil: It's the whole system architecture and planning that makes it work.
04:45 PM SpeedEvil: The robot carrying twice less or more weright, or going twice or half the speed won't actually matter
05:02 PM SomeT: what do u mean?
05:03 PM SpeedEvil: The routing and scheduling is the hard part.
05:14 PM SomeT: you lost me
05:14 PM robotustra: I see some spies in here
05:15 PM robotustra: wanna get secret specs
05:29 PM orlock: SomeT: the hardware's not the important bit - its the software
05:30 PM orlock: SomeT: you could get a cheap forklift and slap some cheap lidar/gamin sensors on it
05:37 PM SomeT: I aint no spy
05:37 PM SomeT: um thats a good comparison
05:37 PM SomeT: forklift robot
05:37 PM SomeT: I see there early patents were for this actually
05:37 PM SomeT: haha
05:47 PM z64555: there's been similar warehouse bots since the 80's, my dad helped develop one using underground cables with telephone transpoders to mark the lanes
05:47 PM z64555: hm, not actually transponder
05:48 PM z64555: Think the lines were pulsed by modems saying a single character for a specific lane
05:48 PM z64555: the bots had a telephone pickup coil to sense the lines
05:53 PM SomeT: cool cool
05:53 PM SomeT: anyway
05:53 PM SomeT: SomeT out
05:53 PM SomeT: thanks fdor help
06:13 PM durrf: lol wow
06:13 PM durrf: 80s robots were dumb
06:13 PM durrf: :P
06:13 PM durrf: and here i am using arduinos for practical jokes, what a time to live in!
06:14 PM z64555: you didn't have a lot of options for embedded systems before the 00's
06:15 PM z64555: the fanciest you could get was a super expensive system on a chip or an FPGA
06:15 PM durrf: for the commercial sector at least :P
06:20 PM z64555: even the military sector was limited in embedded electronics
06:21 PM z64555: they came up with some interesting tricks to do analog computations
07:09 PM anonnumberanon: it's when the US sent a human to space for the first time, that took some really limited resources!
07:10 PM Tom_L: most phones have more �C power than they had on the launch modules
07:11 PM Tom_L: i think they worked thru problems better then
07:12 PM anonnumberanon: what makes you think that? because companies weren't lacking research funding?
08:21 PM z64555: er, who's that direected to, anonnumberanon?
08:21 PM anonnumberanon: to Tom_L
08:22 PM anonnumberanon: because he implies (maybe i m wrong in what i thought he meant) that engineering in general is not like it used to be
08:23 PM z64555: I think he's implying that the standard deviation of engineer's skills has widened over the years
08:24 PM z64555: the presence of more powerful uC's and CPU's allows people to be lazy and get away with it
08:24 PM z64555: but at the same time, allows us to do things that would be impossible 20, 30 years ago
09:21 PM rue_mohr: oh just jam an arduino in it and sell them
09:38 PM robotustra: hmm... no pulleys
09:40 PM robotustra: I need 150 mm diameter pulley
09:41 PM Tom_L: V belt or timing pulley?
09:42 PM robotustra: timing belt
09:42 PM Tom_L: what series?
09:42 PM Tom_L: what shaft diameter?
09:42 PM robotustra: I was thinking to make 1:5 ratio
09:42 PM Tom_L: i'm looking at 3:1
09:42 PM robotustra: 14 mm for small , 63.4 mm for big
09:43 PM robotustra: let's say 30 mm OD for small pulley and ~ 150 mm OD for big pulley
09:43 PM Tom_L: use sdp-si's pulley calculator
09:44 PM robotustra: the width and pitch are optional
09:44 PM robotustra: do they do an specific order?
09:44 PM Tom_L: what shaft size?
09:44 PM robotustra: I told 14 mm
09:45 PM robotustra: and the second shaft is 2.5"
09:45 PM robotustra: == 63.5 mm
09:45 PM Tom_L: oh i missed that
09:45 PM Tom_L: 2.5" shaft???
09:45 PM robotustra: :)
09:45 PM robotustra: yes, why not
09:45 PM Tom_L: hard to find a pulley for it is why
09:46 PM robotustra: if the pulley 150 mm, it's possible to make 63 mm hole in it
09:46 PM robotustra: that's why I'm thinking to do it myself
09:47 PM robotustra: may be from plastic and from aluminum after
09:47 PM Tom_L: 3:1 would give me about 576rpm on the Z axis screw
09:47 PM Tom_L: which is fine for Z
09:48 PM Tom_L: ~48mm/sec
09:48 PM Tom_L: should give it plenty of torque
09:49 PM robotustra: your pulleys are small
09:50 PM Tom_L: 3/8" shaft
09:50 PM Tom_L: and 10mm
09:50 PM robotustra: I would like to drive spindle
09:50 PM Tom_L: ahh yeah i forgot you were doing a lathe
09:50 PM robotustra: from 1.5 kW motor
09:50 PM robotustra: yes
09:50 PM Tom_L: better make sure it's balanced good
09:51 PM robotustra: balancing it's a second step
09:51 PM robotustra: the first step is to make them
09:53 PM robotustra: what type of belts is good for 1000-4000 rpms?
09:53 PM Tom_L: not sure
09:54 PM Tom_itx: http://sdp-si.com/resources/
09:54 PM Tom_L: docs there will tell you
09:55 PM Tom_itx: http://sdp-si.com/resources/beltdesignsuggestions.php
09:55 PM Tom_itx: http://sdp-si.com/resources/beltdesignoperations.php
09:55 PM Tom_L: probably that last one
09:59 PM robotustra: it means I have to use V-belt for spindle
10:00 PM robotustra: and Power Grip GT2 belts for motors
10:04 PM Tom_L: probably so
10:05 PM Tom_L: the motor you chose probably not well suited for a spindle drive
10:05 PM Tom_L: at least not for reduction
10:06 PM robotustra: why?
10:07 PM Tom_L: limits belt choice for one
10:08 PM robotustra: the spindle on the lathe can rotate from 0 to 3600 rpms
10:08 PM robotustra: theoretically
10:08 PM robotustra: timing belts are better for slow operations
10:08 PM robotustra: like up to 100 rpms
10:09 PM robotustra: V-belts are good for fast rotation
10:09 PM robotustra: it's not a problem, I'll install tachometer on a spindle anyway
10:09 PM robotustra: I will need it to make cones
10:10 PM robotustra: and threads
10:11 PM robotustra: may be I'll make smaller reduction, 1:4
10:19 PM robotustra: Tom_L, look at this https://www.ebay.com/itm/HTD3M-48-16-Tooth-16mm-wide-Timing-Pulley-Belt-set-kit-Reducer-Ratio-3-1-for-CNC/262553182885?hash=item3d2163a2a5:m:mflr0VlPFhM3CzhltVoIx0w
10:19 PM Tom_L: yeah?
10:20 PM Tom_L: small pulley is too small imo
10:20 PM Tom_L: how many engaged teeth are there?
10:22 PM Tom_L: for me, you can't find a HTD with a 3/8 shaft
10:22 PM Tom_L: in the sizes i was looking for
11:02 PM rue_mohr: supposedly, if I hook up a usb serial to this old rov, I can make it go
11:33 PM anonnumberanon: i need to order a fuse for that blown milliamp function on my multimeter
11:50 PM z64555: They don't have any of them in the automotive section at the hardware store?
11:50 PM z64555: or walmart/heb/etc.
11:54 PM anonnumberanon: i didn't think of looking
11:54 PM anonnumberanon: maybe Homedepot
11:57 PM anonnumberanon: let's see
11:57 PM anonnumberanon: gotta remember what brand it is i dont have it handy
11:58 PM anonnumberanon: ah, uni-t ut61e
11:59 PM anonnumberanon: "If you want a meter with cheap fuses, get a UT61E. They use BS1362 fuses. Ten a penny, and more than adequate for electronics work"
11:59 PM anonnumberanon: my day just got better :)