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[01:48:50] <anonnumberanon> I want to make an aluminum-working shop.
[01:49:21] <anonnumberanon> Seems like it's 50% of building a nice biped robot.
[01:52:58] <rue_bed> for the most part, you can use woodwork tools on aluminum
[01:55:35] <anonnumberanon> I'd need some good sheet bending method.
[01:56:56] <anonnumberanon> to make stuff like this:
http://thumbnail.image.rakuten.co.jp/@0_mall/grass-road/cabinet/robot/03174256/imgrc0066061429.jpg
[02:09:22] <rue_bed> how long
[02:09:32] <rue_bed> 8" or less?
[02:09:47] <rue_bed> if so, just do it in a bench vise
[02:17:46] <anonnumberanon> yeah less than 8
[02:17:58] <anonnumberanon> don't know
[02:18:08] <anonnumberanon> gotta do homework on this
[02:31:35] <z64555> graphite has been used as contact pressure sensor, dunno about air pressure, however
[04:15:53] <veverak> https://github.com/Schpin/collib/blob/master/test/collision.cpp
[04:16:08] <veverak> I found ASCII picture nice in library that does some graphics
[04:16:15] <veverak> any tips for tool that can generate ascii shapes?
[04:16:21] <veverak> basi geometry... trees would be also nice
[05:23:32] <deshipu> http://asciiflow.com/
[05:23:56] <deshipu> http://ditaa.sourceforge.net/
[05:24:11] <veverak> awesome!
[05:26:30] <deshipu> also aafig
[05:31:47] * z64555 wonders how an image could be fuzzified
[05:34:36] <z64555> you could, like, do a comparison between the input and with the rule image, such as a bitmap of ascii characters
[05:36:26] <z64555> hm. yeah. that might work
[05:36:31] <Jim__> Hello. I'm a software engineer so I'm not familiar with building robots. I want to build a tiny, low-energy, non-moving robot, with a sensor able to detect large object (size of a car) in a given radius (1-10m). I'm here to find hints about where to start from
[05:38:43] <z64555> hey Jim, welcome to the channel. I'm not sure when the regulars wake up, so it might be a while to get a response from the smarter folk
[05:39:03] <z64555> smarter, as in smarter than me :P
[05:40:20] <z64555> I can tell you that you'll probably be working with sonic sensors, a camera range finder, or if you need more sophistication you'll need to look into lidar and/or image processing with a camera
[05:40:47] <Jim__> Alright :p I'm writing from Europe, didn't think of the time difference. I guess this is a mostly american chan
[05:41:39] <z64555> I'm not sure what the demographics are, but I'd wager a fairly even number from around the world
[05:43:40] <Jim__> Ok great thanks for the hints. Lidars seem to be an overkill. Sonic sensors look nice, but most example I found seem to require the sensor to be rotated. Are there sonic sensor that can scan a wide angle without being moved around?
[05:45:36] <z64555> hm, not that I am aware of. Alternatively you could use several sonic sensors operating at different frequencies pointed in different directions
[05:46:21] <Jim__> True. I didn't think of that.
[05:47:06] <z64555> oh, not different frequencies, but different pulse modulations.
[05:47:09] <z64555> sorry
[05:47:15] <Jim__> Is there difference between sonic sensors and range finders?
[05:48:07] <z64555> yes. generally when talking about range finders, they mean the optical variety. Although historically they were either sonic or optical
[05:49:16] <Jim__> Oh I see. But they do the same thing if I understand well
[05:49:50] <z64555> they also have a narrow beam width, so if you need to determine what you're detecting is a wide object then you'd have to use an array of them or resort to lidar
[05:50:33] <z64555> right, with both sonic and optical range finders, they time how long it takes for an emitted pulse to return to its sensor
[05:51:08] <z64555> they often have an internal lookup table to do a quick conversion between time and distance
[05:51:20] <z64555> some of the cheaper sensors might not
[05:53:36] <Jim__> Ok. Reactivity is not a big deal for my project
[05:55:04] * theBear reacts, as if something was a really big deal !
[05:55:19] <z64555> :)
[05:55:21] <Jim__> :o
[05:56:43] <Jim__> Ok so I think I can look into cheap sonic radars / range finders.
[05:57:12] <Jim__> Thanks for the help and explanations!
[05:59:00] <z64555> Welcome :)
[05:59:54] <z64555> It might not be enough to get your project done in one go, but at the very least it'll get you introduced to some core concepts
[06:00:34] <Jim__> Yep that's exactly what I needed
[06:01:19] <Jim__> BTW I guess those things can be hooked up on a Arduino nano?
[06:02:05] <Jim__> Sorry, my questions was actually: do I really need a arduino nano or are there cheaper options?
[06:03:21] <z64555> 4USD is pretty dang cheap for a board. lol
[06:03:45] <z64555> Arduino is a good line for beginners, lots of software API's available
[06:04:06] <Jim__> Ok :D
[06:05:19] <z64555> seeedstudio.com has an interesting collection of electronics. There are also many, many many online retailers
[06:05:53] <z64555> sparkfun is a bit pricier, but they have (or at least had) great support
[06:06:09] <z64555> I haven't bought anything lately, suprisingly
[06:08:41] <Jim__> I found a 15$ sonic sensor on seeed
[06:11:15] <Jim__> I hoped to have a total cost around 5$ since the plan was to make, like, a lot of them. Am I being delusional in your opinion? :p
[06:14:25] <z64555> unfortunately yes. Unless you can find a retailer that sells them in bulk
[06:15:02] <z64555> digikey is one such retailer, but you'd have to buy sensors in the thousands to get them remotely close to what you're thinking
[06:15:47] <Jim__> Ok that's interesting
[06:16:28] <Jim__> I could build normal price prototypes, and if they work well I'll consider buying in bulk
[06:16:59] <Jim__> Ok thanks again! Very valuable informations
[06:23:07] <z64555> You're welcome :)
[06:36:38] <Jim__> One more question if you are still there: are there "magnetic" sensors? I know they use this to detect cars at traffic lights, I wonder if this exists as small sensors, and if there is a specific name for it
[06:40:14] <Jak_o_Shadows> yes.
[06:40:19] <Jak_o_Shadows> Reed sensors for magnets
[06:40:22] <Jak_o_Shadows> induction sensors for metal
[06:40:32] <Jak_o_Shadows> or hall effect sensors
[06:40:36] <Jak_o_Shadows> most are pretty range liited
[06:40:42] <z64555> very. very range limited
[06:41:02] <z64555> their sensitivity decreases parabolically
[06:41:06] <z64555> (x^2)
[06:42:15] <z64555> letsee... for traffic light sensors they have an expanded coil laid underneath the pavement
[06:42:28] <Jak_o_Shadows> Yeah. I figure they do more complicated RF stuff tehre
[06:43:06] <z64555> this is basically a standard helical coil, but they shoved it over to the side instead of stacked on top
[06:44:13] <z64555> a low voltage AC signal is supplied to the coil, and from there they somehow sense the change in inductance
[06:44:19] * z64555 forgot how that works specifically
[06:44:26] <Jim__> Yes I read that too. Seems ingenious. I can't cut out the pavement though :D
[06:45:51] <z64555> hey, just tell the DoT that you're voluntarily fixing potholes. :D
[06:47:19] <Jim__> Haha I'm sure they'll love the idea!
[06:49:35] <z64555> ah, that's how they did it. They put an ammeter in series with the coil and detect the change in current
[06:55:18] <z64555> or otherwise used a wheastone bridge
[11:13:52] <rue_bed> you only need about 2 turns
[11:14:01] <rue_bed> you could tape it down
[11:15:46] <Tom_itx> sun wake you up?
[11:15:47] <rue_bed> ok, what to do
[11:15:55] <rue_bed> no , no sun
[11:16:01] <rue_bed> (??)
[11:16:22] <Tom_itx> do it all in reverse order
[11:16:29] <Tom_itx> for a change
[11:16:50] <rue_bed> I like the idea, but I dont hvae a really big flashlight I can shine in its face
[11:17:36] <rue_bed> just to take it away after it wakes up and say "nevermind, its going to rain today"
[11:19:27] <Tom_itx> https://www.youtube.com/watch?v=jaJQ2fo4poU
[11:20:20] <Tom_itx> better yet:
https://www.youtube.com/watch?v=-vgNh3fLxJc
[11:20:41] <rue_house> I think its going to rain the whole time I'm on holiday
[11:20:53] <Tom_itx> plan a swimming trip
[11:20:54] <rue_house> ah pvc
[11:21:03] <rue_house> shouldhave used a round heatsink
[11:21:15] <Tom_itx> mebbe he didn't have one
[11:22:04] <Tom_itx> i want one of the 2nd one to shine at the neighbor when they wake me up in the middle of the night
[11:22:54] <rue_house> nice
[12:20:46] <rue_shop5> 'if you know its gonna rain, kill a spider',
[12:20:58] <rue_shop5> 'IF YOU KNOW ITS GONNA RAIN KILL A SPIDER!'
[12:21:13] <rue_shop5> 'if you know its gonna rain, and youve given up again, '
[12:21:19] <rue_shop5> 'if you know its gonna rain, kill a spider.'
[12:42:59] <z64555> I'm covered for today, then
[12:44:15] * z64555 goes to pick up the carcass to trash it, only to find that it isn't there
[12:44:25] <z64555> well crap. looks like I'm going to be haunted by a ghost spider
