#robotics | Logs for 2016-06-29

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[09:34:15] <rue_house> so I need to frame serial data
[09:34:22] <rue_house> and I need almost no overhead
[10:05:45] <SpeedEvil> define serial
[10:05:48] <SpeedEvil> and frame
[10:05:57] <SpeedEvil> rs232 framing is quite minimal
[16:39:05] <Loshki> rue_house: thank you for your solution. We will deliver your problem shortly.
[18:42:16] <z64555> rue_shop3 it's only a thousand LEDs
[18:43:08] <Snert_> maybe they are 3mm instead of 5mm leds.
[18:43:20] <Snert_> would occupy alot less real estate.
[18:43:25] <z64555> If it took about 2 second per LED, then it would only be half an hour of toiling
[19:21:02] <rue_house> gee thanks
[19:45:15] <kcirick> I have a question about batteries... If I want to power 2 motors, each drawing 3V @ 1.5A stall current, would 3S LiPo (11.1V) be too high voltage?
[19:45:57] <Tom_itx> E=IR
[19:46:37] <Tom_itx> current limit them
[19:47:02] <kcirick> So having a battery that has higher voltage rating won't hurt the motors?
[19:47:56] <kcirick> The battery I am looking at is rated 20C (RC battery), which as I understand has continuous current output of 20A
[19:47:57] <rue_bed> pwm
[19:48:29] <rue_bed> the current is only drawn if there isload
[19:48:38] <kcirick> rue_bed: Ah, so you can use PWM to lower the average voltage?
[19:48:44] <rue_bed> yuea
[19:49:10] <Tom_itx> i run my 2v steppers off 48v ;)
[19:49:58] <kcirick> so there is no harm in getting 11.1V battery then, it seems cheaper than 7.4V, probably because it's more common
[19:52:18] <kcirick> I tried running 8 AA batteries (4 x 2) in parallel, but still wasn't enough power for a tracked rover on carpet when turning
[19:52:41] <kcirick> As I undertsand AA battries suck at outputting good current
[19:54:05] <Snert> they do well at supplying the load they were intended for
[19:54:37] <Snert> some things just want too much current though
[19:54:55] <Snert> better off with a lipo
[19:55:52] <kcirick> Snert: Yeah, I'm going to get a lipo. Is there anything I should know about chargers?
[19:56:15] <kcirick> I'm looking at this: https://www.amazon.ca/gp/product/B00SWP6TEQ/ref=ox_sc_act_title_1?smid=A1B4V5VJQK2QAS&psc=1
[19:56:38] <Snert> get a decent one is all. Not that one.
[19:56:45] <kcirick> I really don't care how long it takes to charge, just want it not to burn my house down
[19:56:48] <kcirick> oh okay
[19:57:08] <Snert> https://www.amazon.com/s/?ie=UTF8&keywords=lipo+rc+charger&tag=googhydr-20&index=aps&hvadid=36271491400&hvpos=1t1&hvexid=&hvnetw=g&hvrand=5841593753679805309&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_2ri9cybepl_b
[19:57:19] <Snert> any of the hobby sites sell good lipo chargers.
[19:57:54] <kcirick> Snert: what makes a good charger? What should I look for?
[19:58:54] <Snert> beyong googling and research.....
[19:58:58] <Snert> http://www.hobbyking.com/hobbyking/store/RC_PRODUCT_SEARCH.asp?searchType=10&strSearch=lipo+charger&location=AL&idCategory=&sortBy=Relevant&NumPerPage=20&currentPage=2
[19:59:37] <Snert> the RC helicopter world and rc car worlds is where to read about what makes a good charger.
[19:59:49] <Snert> + assorted googles.
[19:59:58] <kcirick> Snert: Ok. I guess I have some reading to do. Thanks
[20:00:09] <Snert> Me? I just spend a hunnert bucks.
[20:00:40] <Snert> a hundred dollar charger is always good enough for me when I want to charge 4 lipos at once.
[20:01:07] <Snert> I just stay away from the little wall wart chargers.
[20:01:20] <kcirick> Snert: I have other expensive hobbies :-)
[20:01:52] <Snert> Serious - check out helifreak.com
[20:02:19] <Snert> that forum has a whole section on lipos and chargers and will get you familiar with what is state of the art.
[20:03:06] <kcirick> Snert: awesome
[20:04:32] <Snert> we can answer questions here too, but what you need is to really see what everyone else is using.
[20:06:16] <kcirick> Sounds good... Always learning something here. Will be back to learn something else in the near future. Thanks all!
[21:07:56] <robotustra> hey boys and girls
[21:14:37] <robotustra> I see all my friends on the same place in here :)
[21:16:59] <robotustra> any news?
[21:18:25] <rue_bed> nope
[21:18:51] <rue_bed> oh, there is progress on the pipe roller for the cage to control the 12' mecha
[21:56:35] <robotustra> good
[21:56:59] <robotustra> I also have small progress with wheeled base
[21:57:07] <robotustra> for robot
[23:04:50] <anonnumberanon> beer time
[23:05:00] <anonnumberanon> for an hour at least
[23:05:28] <anonnumberanon> get to understanding a hobby program or watch 2nd world war documentary
[23:05:38] <anonnumberanon> ?
[23:11:47] <robotustra> ask your master