#robotics Logs

Jun 17 2017

12:05 AM rue_house: wait wait wait
12:07 AM rue_house: you HAVE heard of a flame triode havn't you!?
12:07 AM Tom_itx: nop nop nop
12:07 AM * rue_house interrupts tom
12:07 AM z64555: that anything like those little candle lightbulbs?
12:13 AM z64555: hmm, at any rate, I'll need a source of tubing
12:13 AM z64555: I could always buy that, but where's the fun in that
12:14 AM * z64555 researches glass tubing extrusion
12:16 AM z64555: hm, I saw a homebrew plastic extruder once. wonder if that could be adapted for glass
12:18 AM * aberon deplores the fact there is no good function to call a target number of NOPs
12:19 AM Jak_o_Shadows: WHY has the USB HID people gone into such specifics
12:20 AM Jak_o_Shadows: p38 of this: http://www.usb.org/developers/hidpage/Hut1_12v2.pdf
12:20 AM z64555: aberon: macros
12:21 AM z64555: orrr
12:21 AM z64555: Have a section in memory that's just a list of nops
12:21 AM z64555: each nop has a label which can be jumped to
12:21 AM aberon: :0
12:21 AM z64555: not list, an array
12:21 AM z64555: So
12:22 AM z64555: Jump to whichever nop you want, then go down the line to a branch-not-equal
12:22 AM z64555: It'll loop across the nop for however many times you want
12:23 AM aberon: wait is this a clever hack that works?
12:23 AM z64555: I see no reason it shouldn't. The only downside is the cycle bloat from the branching
12:23 AM aberon: i don't understand the "jump to whichever NOP you want"
12:24 AM z64555: lemme pastebin
12:24 AM aberon: ty
12:26 AM rue_house: z64555, its a precition delay
12:29 AM z64555: https://pastebin.com/MJqmPWNK
12:29 AM z64555: my assembler's a bit rusty, but hopefly you get the idea
12:30 AM * mrdata swats at hope-flies
12:30 AM rue_house: yea, they change the label etc to get a different delay
12:30 AM rue_house: if its a processor that you can modify the program space realtime, you can rewrite the jump to get different delays
12:31 AM z64555: Probably better to use a timer module for larger delays
12:32 AM z64555: and have it trigger an ISR while you put the CPU to sleep or have it work on something else
12:32 AM z64555: but if you've got a classic project and all your timers are occupied...
12:33 AM z64555: my dad once debugged a micro using a transistor radio
12:35 AM z64555: Jak_o_Shadows: what the
12:36 AM aberon: z64555, that code looks interesting I'll try to put a test together
12:37 AM aberon: the timers were shit last time i checked i forgot why
12:37 AM z64555: Jak_o_Shadows: did you see page 42??
12:37 AM aberon: oh yeah, cause their definition/precision was not good enough
12:38 AM aberon: and here we're talking not being able to get an accurate microsecond i think it was
12:38 AM aberon: last time i was experimenting was, wait
12:39 AM aberon: 10 months ago
12:39 AM z64555: you can use the timer in conjunction with the nop loop
12:40 AM Jak_o_Shadows: magic carpet?
12:40 AM z64555: timer to do bulk delays, and the nop for finer control
12:40 AM z64555: Jak_o_Shadows: yes
12:40 AM Jak_o_Shadows: yeah.
12:40 AM Jak_o_Shadows: I just want "analog 1. analog 2. analog 3..... analgo 13"
12:40 AM aberon: z64555, yeah i like that
12:41 AM aberon: anal, go do it, it's 13 inch long
12:42 AM z64555: (not this channel, plz)
12:42 AM z64555: Jak_o_Shadows: this .pdf is the hardcoded id's of what HID it is?
12:42 AM Jak_o_Shadows: Something like that I think?
12:43 AM z64555: I fail to see the reason they need to be this specific
12:44 AM Jak_o_Shadows: Maybe it's one of those "it was meant to work like this, but no-one does it" things?
12:44 AM z64555: kinda like some parts of unicode...
12:46 AM z64555: well
12:46 AM z64555: at least they're still only using 2 bytes
12:47 AM z64555: hmm
12:48 AM z64555: Looks like the tubing extruder uses an air column in the middle to form the cavity
12:48 AM z64555: it has a rammer to force material into the chamber and then through the die
12:49 AM z64555: There' a back-pressure regulator to make sure the air pressure doesn't build up too much
12:57 AM z64555: aberon: just keep in mind, the branching takes a few cycles
01:08 AM aberon: yeah so should they
01:08 AM aberon: the challenge is to make it predictable
05:45 AM SpeedEvil is now known as Guest44341
09:33 AM BitEvil is now known as SpeedEvil
01:07 PM rue_bed: ah morning double blurry vision
01:07 PM rue_bed: hipeople
01:07 PM rue_bed: 10:30 morning
01:07 PM rue_bed: 2am night
01:08 PM rue_bed: ok,,, there is a mission
01:08 PM rue_bed: a) wake up
01:08 PM rue_bed: zzzzzzzzzz
01:09 PM rue_bed: I need an antigravity bed, this one is folding me wrong
01:17 PM z64555: ?
02:34 PM veverak: so
02:34 PM veverak: question is
02:34 PM veverak: https://www.aliexpress.com/item/Cheap-Big-Smart-Robot-Tank-Chassis-Kit-diy-robot-chassis-track-tank-full-set-track-Yellow/32356285994.html
02:34 PM veverak: can I hack encoders into this?
02:35 PM veverak: but that looks like it's suspension is fake
02:35 PM veverak: nah
02:46 PM robopal: would you buy something that has "cheap" in its title?
02:47 PM robopal: it is a toy, dont bother
02:53 PM veverak: I would
03:03 PM robopal: come onnnnn
03:03 PM robopal: dont
03:25 PM Tom_itx: what is a .upd file?
03:35 PM z64555: veverak: the suspension is fake, but it looks like you've got enough room to drill hole for #6 or #8 screws and use some spring stock to fabricate the torsion bars
03:37 PM z64555: hm
03:38 PM z64555: would need some sort of channel drilled/fabricated for the idlers to travel up/down
03:39 PM z64555: version E looks more promising
03:40 PM z64555: suprisingly, it is also cheaper
03:45 PM z64555: I worry about lateral forces, tho
04:08 PM robopal: Tom_itx, update?
04:09 PM veverak: z64555: seems like its' easier to build custom one
05:14 PM z64555: probably so
05:39 PM Tom_itx: robopal, yeah thanks. i figured it out
06:39 PM rue_shop3: tearing down one of 4 boxes of power supplies, I alsmost have it down to the top of the box
07:05 PM rue_shop3: I dont understand
07:06 PM rue_shop3: I know that if I empty a box, and try to put everything back in it, they dont fit
07:06 PM rue_shop3: but I taken about 7 baords out of the top of this box and its still just as full as it was
09:04 PM rue_shop3: I have to rotate soldering guns, I'm on tips 7 and 8
09:15 PM Jak_o_Shadows: My last tip was horrible. So I used the bench grinder on it
09:18 PM rue_shop3: I stripped 22 power supplies, and the box is just a little lower than the top
09:18 PM rue_shop3: I need to give my ass a break
09:19 PM rue_shop3: :/ this is the smallest of 4 boxes
10:30 PM asdasdasd: hey!
10:30 PM asdasdasd: robotics student here
10:31 PM asdasdasd: anyone know if willow garage published full parts breakdown of PR2?
10:52 PM z64555: never heard of em. D:
10:54 PM z64555: doing a google search for the PR2, sould be anywhere on the spectrum as "hey I can do that" to "gonna need a bigger shop"
10:54 PM z64555: *could
10:56 PM z64555: hmm
10:57 PM z64555: This is a "gonna need a bigger shop"
10:57 PM rue_house: ?
10:57 PM rue_house: url?
10:57 PM z64555: http://wiki.ros.org/Robots/PR2
10:58 PM z64555: could probably make a much less fancy version of it with just the sensors and the arms
10:58 PM rue_house: it looks big, but is it?
10:58 PM Jak_o_Shadows: WHY. The first two bytes of the data packet are just from 0-255, but windows joystick is saying that x-axis (byte 1) goes from -stupid to stupid, and y-axis(byte 2) goes from -7 to 7
10:58 PM rue_house: asdasdasd, your f key didn't seem tow ork btw
10:59 PM z64555: rue_house: it's supposed to be able to extend to about human height or something
10:59 PM rue_house: Jak_o_Shadows, sounds like a size type mismatch
10:59 PM rue_house: hmm
10:59 PM aberon: PR2 looks
10:59 PM aberon: hot
10:59 PM * rue_house redesignes his new shop with more robot building space
10:59 PM Jak_o_Shadows: Yeah rue. But I haven't bloody changed much from the old code
11:00 PM z64555: PR2 is not a Mr. Handy
11:01 PM rue_shop3: :/ 22 boards and im no further ahead
11:02 PM rue_shop3: just like the 5 printers i stripped down off the deck
11:02 PM Jak_o_Shadows: apparently this is a job for linux
11:57 PM Jak_o_Shadows: Yup. it is an alignment issue I think