#robotics | Logs for 2017-01-12

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[13:02:54] <i-make-robots> hey all. quick question! I have an STL 3d model of a head. Instead of being solid all the way through, there's a pocket in the head where the brain should be. How would you remove the pocket?
[13:05:01] <z64555> STL, hm?
[13:05:04] <z64555> lemme check
[13:06:05] <z64555> oh
[13:06:18] <z64555> i-make-robots: just remove the vertices of the inner cavity
[13:08:05] <z64555> If your CAD program supports selection of edges by loops and rings, it would be a piece of cake
[13:09:19] <z64555> Unless there's something more to the model than what is immediately apparent?
[13:12:54] <z64555> I'd imagine that the inner volume has its normals facing inward, so as to distinguish it as a "negative" volume
[13:31:56] <i-make-robots> z64555 - yes, it's how to select them that's the challenge. I don't have a good software tool to select and delete.
[13:32:01] <i-make-robots> I'm trying meshmixer atm.
[13:32:36] <i-make-robots> it's still generating a model with +250k faces. trying to bring that down far enough to edit the model in fusion360. need to mod it for a blind person's cane.
[13:50:50] <z64555> What's wrong with blender?
[13:51:16] <z64555> there's plenty of modeling programs out there
[13:53:00] <z64555> hm
[13:53:11] <z64555> Fusion360's an AutoDesk product
[13:55:33] <z64555> sigh
[13:55:38] <z64555> AutoDesk dissapoints me
[13:56:50] <Tom_itx> hah
[15:13:04] <i-make-robots> nothing espcially wrong with blender. just... i don't grok it yet.
[15:14:36] <z64555> Yeah, it's UI is a mess, even after the 4th re-do
[15:15:00] <z64555> just use a bunch of key combos to get the submenus you want
[22:38:08] <rue_house> 15W40, another part number that impossable to search for on the internet
[22:39:47] <orlock> hah yes
[22:43:10] <rue_house> my eyes were crossed, its 15w401
[22:43:19] <rue_house> still, really obscure
[22:45:03] <orlock> rue_house: my "new" telescope mount - i got second hand 6 months ago
[22:45:27] <orlock> i cracked open the handset controller to check out the PCB, and assumed that i'd be able to google the PCB model number
[22:45:32] <orlock> not one result - even a wrong one
[22:45:47] <rue_house> hmm
[22:45:55] <rue_house> didn't you say it was a popular one?
[22:45:59] <orlock> suprising, as it's used on a while pile of different mounts, and it shuold be trivial to replace with an AVR to give these mounts serial control
[22:46:02] <orlock> yeah!
[22:46:06] <rue_house> maybe your the oly bridge between telescopes and electronics
[22:46:45] <orlock> These mounts (QE5/HEQ5/HEQ5 pro/EQ6/NEQ6) basically have two choices of controller
[22:47:00] <orlock> the "simple" style which is "dumb" with a bunch of buttons - thats what i have
[22:47:06] <orlock> then there's the "smart" style
[22:47:12] <orlock> which is a $1000 upgrade
[22:47:35] <orlock> that ads a "PC" capable serial interface, and has a built in object data,ase, smart slewing to positions, etc etc
[22:47:46] <orlock> none of which i care about
[22:48:05] <orlock> i just want to be able control speed/direction from the PC
[22:48:16] <rue_house> is the dumb one just serial keyboard?
[22:48:28] <orlock> Apparently nobody else has bothered trying to do it - or if they have, they didnt document it
[22:49:44] <orlock> I think it's literally just a box of buttons
[22:49:46] <rue_house> I was just gonna pick up a microswitch and eat it, I wonder if I'm hungry
[22:50:02] <orlock> broken out to an RJ12
[22:50:18] <orlock> that's next on the list after i finish re-erranging my workshop
[22:50:20] <rue_house> funny, I made the same thing w/ my cnc pendant
[22:50:21] <orlock> added another workbench
[22:50:28] <rue_house> but the recieved data goes to an lcd
[22:50:51] <rue_house> 12V powered, serial buttons out, lcd data in
[22:51:07] <orlock> yup
[22:51:45] <rue_house> huh, this is a 8051 varriant
[22:52:30] <rue_house> part number convention dosn't match tho
[22:53:31] <rue_house> oh no there we go
[22:54:57] <rue_house> so its flash is not available for data, its an 8051, 5.5-2.5V, 4k ram?, 1k program space, feature codes dont fit...
[22:56:15] <rue_house> on this board... https://www.aliexpress.com/item/5V-12V-DC-Brushless-Driver-Board-Controller-For-Hard-Drive-Motor-3-4-Wire-New/32700019464.html
[22:56:47] <rue_house> they used a micrcontroller to convert the pot to a control frequncy
[23:00:25] <rue_house> oooooh interesting
[23:00:54] <rue_house> to get around the 120 day limit, at the 60 dy mark, the seller would rather send me another one than extend the purchase protection...
[23:02:14] <rue_house> pfff, I have a seller that I dont think understands how to refund
[23:03:27] <Jak_o_Shadows> I just got 20 of the little servos in the post
[23:03:34] <rue_house> :)
[23:03:42] <rue_house> do more than 15 work?
[23:04:22] <Jak_o_Shadows> I have no clue
[23:04:25] <Jak_o_Shadows> Gotta find my servo tester
[23:04:36] <Jak_o_Shadows> (which in itself is tempermental)
[23:04:51] <rue_house> do you have a tiny13 you can program?
[23:05:11] <rue_house> if so, I have a voltage->servo pwm firmware
[23:05:42] * rue_house waits for a yes, so he can add another project to the github
[23:06:12] * rue_house tires to work out what to have for supper, these microswitches are a bit too crunchy
[23:07:39] * Wetmelon had my 2nd robotics class today
[23:07:42] <Wetmelon> Man this shit's boring lol
[23:07:48] <rue_house> what did they do?
[23:07:56] <rue_house> basic pyhsics?
[23:08:02] <rue_house> time a pendulum?
[23:08:09] <Wetmelon> Rotation matrices
[23:08:16] <rue_house> ah
[23:08:20] <Wetmelon> and talked about degrees of freedom
[23:08:21] <rue_house> 4x4?
[23:08:24] <Jak_o_Shadows> I have no way of programming atmel stuff
[23:08:25] <Wetmelon> 3x3 for now
[23:08:36] <Jak_o_Shadows> I like the idea of introducing 3x3 first.
[23:08:39] <rue_house> Jak_o_Shadows, bull, you have not a computer with a space pata port?
[23:08:40] <Jak_o_Shadows> It's the hard part
[23:09:22] <rue_house> the extra 1 makes 3d operations much friendlier, but I'm not of good oppinion cause I hate matrixies
[23:09:32] <Wetmelon> He actually did a 2x2 first via sin/cos laws and all that proof bullshit, then immediately extended it to 3x3
[23:09:34] <rue_house> Jak_o_Shadows, pata?
[23:09:40] <Wetmelon> parallel ata?
[23:09:44] <rue_house> yea
[23:09:55] <Jak_o_Shadows> Not currently running. The spare computer that is going to the shed has one, and a parellel port, and a serial port, but it isn't running
[23:09:57] <rue_house> or a parallel printer port is even better
[23:10:05] <Wetmelon> Is it AVR?
[23:10:11] <rue_house> Jak_o_Shadows, your machine has no pata ports in it?
[23:10:21] <Jak_o_Shadows> Nope. It's a very odd motherboard.
[23:10:26] <rue_house> ugh
[23:10:32] <Wetmelon> You can buy $10 usb/iscp avr programmers
[23:10:36] <rue_house> how about using the 5x usb hub method?
[23:10:48] <Jak_o_Shadows> Either way, I have stm32's right next to me, and I could make one of them drive a servo easy enough.
[23:10:50] <rue_house> you can also buy the $2 ones, I tried and they work fine
[23:11:06] <rue_house> oh but you'd have to write all that software
[23:11:15] <rue_house> thats 2 weeks of work
[23:11:17] <rue_house> :)
[23:11:24] <rue_house> (discontinious)
[23:11:37] <rue_house> I have 7 of them next to me
[23:11:41] <rue_house> how you programming yours?
[23:11:44] <rue_house> bootloader?
[23:11:49] <Jak_o_Shadows> pfft. I know how to make a timer toggle a pin, and the timers have a servo pwm mode
[23:11:55] <Jak_o_Shadows> nah. Openocd through a st-link
[23:12:01] <Jak_o_Shadows> (a knock-off st-link)
[23:12:09] <rue_house> I got a programmer, but there were fuses set in what I think is a bootloader they come with that made life a nightmare
[23:12:25] <rue_house> ok same as what I did
[23:12:46] <rue_house> how many stm32 projects have you done so far?
[23:12:58] <rue_house> I did a flashing led, to rough out the dev env.
[23:13:02] <Jak_o_Shadows> I've got 2 different stm32 blue pill boards, and haven't had issues programmign either.
[23:13:22] <rue_house> I got the stm32 arduino boards, which have a bootoader or soemthing on them
[23:13:29] <rue_house> but man were they cheap
[23:13:43] <Jak_o_Shadows> i did a fairly big one last year with a more powerful stm32. Interfaced to a parallel camera, saved the image to ram and stuff.
[23:14:22] <Jak_o_Shadows> With the smaller one, i've been through toggling a LED, reading analogue values and buttons, i2c master (and slave, but DON'T TRY THAT), and joystick USB HID.
[23:14:45] <Jak_o_Shadows> Yeah. the i2c hardware is borked, which is annoying, and they don't have ethernet. But most other ARM's are expensive
[23:14:50] <rue_house> oo can you post the adc code?
[23:15:43] <rue_house> there is always ENC28J60 :)
[23:17:19] <rue_house> that would be somehting worthy of a STM32, some kinda ethernet device
[23:17:33] <rue_house> oooo like my io controller thats listens to the message server
[23:17:47] <rue_house> 8-) hmmmm
[23:18:45] <rue_house> https://github.com/xaionaro/stm32-enc28j60
[23:18:46] <rue_house> hmmm
[23:18:47] <Jak_o_Shadows> Erm, it's not using direct register access. It's using a library - not the stm one either.
[23:18:59] <Jak_o_Shadows> rue, I am seriously thinking CAN for home automation
[23:19:10] <rue_house> I'm using i2c and ethernet
[23:19:21] <rue_house> I have a message server that runs on a automation machine
[23:19:40] <rue_house> you conenct to it paintext, and anything you say is echod to everyone else connected
[23:19:45] <Jak_o_Shadows> https://github.com/Jak-o-Shadows/simpanel/blob/master/code/main.c this has the ADC in it. Line 617
[23:19:59] <rue_house> when you connect, your given a unique client id
[23:20:16] <Jak_o_Shadows> How are you finding i2c? Isn't there a run length limit? How are you doing the physical bits of things?
[23:21:20] <rue_house> hmm no init_adc() and read_adc()
[23:21:46] <rue_house> hah, I have an i2c bus running ~100 feet end to end in the house, thats star wired in the not-middle
[23:21:48] <rue_house> and it works
[23:21:59] <rue_house> with no terminators
[23:23:04] <Jak_o_Shadows> I suppose I'm doing the init_adc() way up above on line 388ish
[23:23:08] <Jak_o_Shadows> Nice.
[23:23:39] <rue_house> where is the library from?
[23:23:48] <rue_house> that was a point of some fun for me
[23:24:08] <rue_house> there seem to be a bunch of libraries, I found 3 'main' looking ones
[23:25:05] <Jak_o_Shadows> This is unicore-mx (https://github.com/insane-adding-machines/unicore-mx), but libopencm3 (https://github.com/libopencm3/libopencm3) would work, and is a more direct reading of the reference manual
[23:25:19] <Jak_o_Shadows> They are in opposition to stmcube, and the stm32 std. periph library
[23:34:28] <Wetmelon> Jak_o_Shadows: CAN is nice, CANOpen might be nicer for home automation
[23:35:15] <Jak_o_Shadows> Yeah, Wetmelon, I hadn't gotten around to protocol design