#avr Logs
Jul 17 2017
#avr Calendar
08:57 AM enhering: hi
09:41 AM Emil: Morning
09:41 AM Emil: Wait
09:41 AM Emil: Evening :D
09:49 AM LeoNerd: "Hi" :)
10:08 AM eszett__: Hi!
10:08 AM eszett__: Emil..
10:09 AM eszett__: You recommended me exp-tech yesterday
10:10 AM eszett__: They seem to be really convenient. I wrote them a mail asking if the have the GPIO hammer headers, and they answered no, but they ordered the parts now expect them to be there in the next 2 weeks.
10:10 AM eszett__: http://www.exp-tech.de/solderless-gpio-hammer-header-female
10:10 AM eszett__: (I'm from Germany)
10:12 AM eszett__: is it possible to cut a 2x3 block with a handsaw out of it? http://i.imgur.com/k3KApmn.jpg
10:18 AM enhering: eszett__: Yep, but you should cut two positions away from the position you want
10:18 AM enhering: Then you can use sand paper to reach the size you need
10:19 AM enhering: better to use a hi speed cutting disk, like the ones Dremel comes with
10:19 AM eszett__: like cut a 5*2 block out of it and then sand it down to 3*2?
10:19 AM enhering: The positions are separated by thin walls.
10:19 AM enhering: if you press too much from the outside the inner walls collapse
10:19 AM eszett__: ah, can't spot them from the picture
10:20 AM enhering: so you must leave one or two to brake down by accident and be sure the pins you need are not affected
10:21 AM enhering: But if you use a cutting disk the cut can be more accurate
10:21 AM eszett__: right, it should be a very small cutting disk then
10:21 AM enhering: and fast
10:21 AM enhering: and, as soon as the pin is released, remove it
10:22 AM enhering: you can use a big cutting disk too, but it must be fixed and your hands must be protected
10:22 AM enhering: always use protecting goggles
10:23 AM eszett__: ah.. all that for a simple header pin block =)
10:23 AM eszett__: Maybe I can use my solder iron to melt a 4*2 block out of it, and the sand it down to 3*2
10:25 AM cehteh: bandsaw with fine blade should be good
10:26 AM cehteh: reminds me to put a fine blade on my to-buy list :D
10:27 AM eszett__: ye
10:28 AM Emil: eszett__: I'm glad I could help : )
10:28 AM Emil: eszett__: I have no affiliation with them but we ordered from them for a course and it worked nicely : )
10:29 AM enhering: A dremel 4000 is always a good assistant.
10:29 AM eszett__: It helps that they speak my mother tongue, coz my english is just to superficial
10:29 AM eszett__: s/to/too
10:29 AM enhering: In fact any dremel with minimum set of tools is good enough
10:30 AM enhering: eszett__: You may count engish natives here with one hand, probably
10:31 AM eszett__: really
10:34 AM cehteh: i dont own a dremel, since the one i had broken
10:34 AM cehteh: dont really miss it
10:36 AM enhering: mine works nice. what happened to yours?
10:42 AM cehteh: forgotten, that was many years ago
11:20 AM enhering: cehteh: can I use one of these to tether the multicopter? http://produto.mercadolivre.com.br/MLB-829473892-fonte-chaveada-e-estabilizada-12v-60a-720w-1-linha-_JM
11:22 AM cehteh: use batteries
11:22 AM enhering: I've got only one. Limited test time
11:22 AM cehteh: buy another one :D
11:23 AM enhering: I had the impression you would write that
11:24 AM cehteh: copters have a very varying current demand may easily even overload the power supply, at these low voltages you need fatass thick cables, which weight a lot and will affect flight stability
11:24 AM enhering: makes sense
11:27 AM enhering: There is this one too: http://produto.mercadolivre.com.br/MLB-718273111-fonte-automotiva-60a-24v-_JM
11:27 AM enhering: thinner cables
11:28 AM bss36504: eszett__: You can also cut with a hot utility knife or scalpel blade. Heat with lighter/torch, cut. That saves your soldering iron tips.
11:30 AM eszett__: bss: that sounds like an even smarter idea. Ye I heat up the cutting blade or a cutter knife!
11:37 AM cehteh: enhering: the cales which you would use to tether it
11:38 AM cehteh: enhering: and i dont think your ESC's and motors will work at 24V
11:38 AM enhering: need to be 6s escs
11:39 AM cehteh: and other motors
11:39 AM enhering: ok
11:39 AM cehteh: so it absolutely makes no sense, new battery is cheaper
11:39 AM enhering: not here
11:40 AM cehteh: cheaper than 4 motors+ 4 esc's + power supply + cable + things you buy again because it failed
11:40 AM cehteh: you are where?
11:40 AM enhering: brazil...
11:41 AM cehteh: i bet there are people doing drone races too and shops selling parts
11:41 AM enhering: all imported
11:41 AM cehteh: well still import one or 2 small 3cell batteries might be a bit more expensive than buy locally but should work
11:43 AM enhering: https://www.hobbystyle.com.br/lipo-lithium-polymer/bateria-lipo-3s/
11:44 AM cehteh: dont use the 25C ... you prolly need 30-35C at least
11:45 AM cehteh: what are the specs about the one you have on the copter? and it is already puffed up or?
11:47 AM cehteh: https://hobbyking.com/de_de/zippy-compact-1600mah-4s-35c-lipo-pack.html
11:47 AM cehteh: oh thats already 4S :D
11:48 AM cehteh: better stay with 3S you dont want racing
11:50 AM enhering: sory. changing diapers. I'll check the links
01:28 PM FrankD: Hey, does anyone here use Robot Room's CopperConnection? My SSD died, I was looking for a link to a version before ExpressPCB bought them out.. paid $99 for it last year :\
01:34 PM Keeermit: Hi, somebody could help me, I try to set an external clock with avrdude but there are too many option, I'm so confused...
01:34 PM LeoNerd: Pick fuse values, provide them on commandline, done
01:35 PM LeoNerd: And be sure you *really* mean "external clock" and not "crystal"
01:35 PM LeoNerd: I.e. you already have a source signal that oscillates by itself
01:36 PM Keeermit: In fact, it's a piezo...
01:36 PM LeoNerd: Uhmm
01:36 PM LeoNerd: A what?
01:37 PM Keeermit: This is for this project : http://www.micro-examples.com/public/microex-navig/doc/077-picobat.html
01:37 PM Keeermit: I'm trying to make this project with an ATtiny85 instead of a PIC12F
01:37 PM LeoNerd: Weelll... first off, that's a PIC not an AVR
01:37 PM Keeermit: Yes I know ;)
01:38 PM Keeermit: The goal is to do the same thing with an ATtiny85
01:38 PM LeoNerd: Also it suggests the piezo element is replacing the resistor in an RC oscillator
01:38 PM LeoNerd: Oh .. or not. Hrm..
01:39 PM LeoNerd: Anyway, you probably want the crystal mode, not the external clock mode
01:39 PM LeoNerd: since this isn't an external clock
01:40 PM Keeermit: Ok! Maybe the crystal low-frequency mode
01:40 PM Keeermit: Because piezo will give around 20khz - 200khz
01:40 PM LeoNerd: That's probably more appropriate yes
01:40 PM LeoNerd: also the kind of power levels involved
01:41 PM Keeermit: Hm yes, maybe I'll need to test some prescaler clock option
01:42 PM Keeermit: (avoid the divide by 8...)
01:42 PM enhering: Sorry, cehteh. Had to stay with the kid
01:43 PM cehteh: heh .. i thought you changed your own diaper :D
01:43 PM enhering: Not yet... :)
01:43 PM cehteh: (jk not really)
01:44 PM enhering: Maybe in more 40 years I will
01:44 PM enhering: About 4S, I thought higher voltages meant lower currents. But that is valid only in low KV motors, right?
01:45 PM enhering: I mean, that is usefull only in low kv motors
01:45 PM enhering: and low kv motors are big and strong, meaning more danger
01:51 PM Emil: Hmm
01:51 PM Emil: Any opinions
01:51 PM Emil: Driving a relay
01:52 PM Emil: High impedance vs push-pull
01:54 PM cehteh: enhering: for the same power/lift it means lower current, yes, but running the same motor at higher voltage generates more power ..
01:57 PM Emil: So switching between highz and vcc agains ground or ground and vcc against gnd
02:04 PM cehteh: you dont need any complicated driver, a relay coil is never floating nor will it trigger on small transitents
02:06 PM cehteh: small fet, diode, 2 resistors
02:06 PM cehteh: and maybe snubber on the switch side
02:18 PM Emil: cehteh: matey
02:18 PM Emil: I kno2
02:18 PM cehteh: why do you ask then?
02:19 PM Emil: Because push-pull is valid aswell
02:19 PM Emil: Also hot damn having a server in your room rises the temp :D
02:20 PM Tom_itx: put it in the basement
02:20 PM Tom_itx: they're always cool
02:20 PM Tom_itx: they are kinda handy in the winter though
02:21 PM Emil: As a student living in a single room apartment
02:21 PM Emil: I have no basement
02:21 PM Emil: Also these boards I ordered
02:21 PM Emil: SHIT'S SMALL
03:05 PM Jartza: small shit is small
06:01 PM Emil: Gah
06:02 PM Emil: Just realised that C has no real else if construct
06:02 PM Emil: there's only if () {} and else {}
06:05 PM Snert__ is now known as Snert
06:08 PM xentrac: no, else takes a statement, not a block, so you can put an if statement there
06:10 PM xentrac: more recent languages commonly use a separate grammatical construct so they can require the blocks to be blocks, for example to prevent gotofail
06:11 PM xentrac: this is sort of like "C has no real arrays" and "C has no real pass-by-reference" and "C has no real strings" :)
06:12 PM xentrac: also "C has no real booleans", "C has no real characters", and "C has no real memory management"
06:12 PM LeoNerd: C doesn't have much that's real
06:13 PM xentrac: and "C has no real macros"
06:13 PM xentrac: and "C has no real type checking"
06:13 PM xentrac: all true to a degree!
06:14 PM xentrac: C has a minimum of mechanism for each of these things, which works well enough much of the time to enable you to get stuff done
06:32 PM * LeoNerd ponders how to go about describing/selling a bare PCB on tindie
06:42 PM eszett: Hi!
06:42 PM eszett: allow me the odd question, but is a MCU like the Atmega actually water proof, or are there some small openings where water can enter the chip itself?
06:43 PM LeoNerd: I'd imaagine the plastic case is prettymuch liquid-tight, but the problem is that at least actual *water* will get on the legs and cause all sorts of problems
06:43 PM LeoNerd: Something like mineral oil might be OK though
06:57 PM twnqx: no, actually ICs do have water problems
06:58 PM twnqx: at least that's what MSLs are about, and why they can explode when soldered if not dried enough (well, professionally, soldered)
07:06 PM Emil: I dont think the materials are designed to handle long term submergion
07:06 PM LeoNerd: (submersion)
07:06 PM Emil: Thamks
07:06 PM Emil: I thought it was wrong :D
07:06 PM Emil: But am already in bes
07:07 PM Emil: Would be waste of resources to use water resistant materials if they are more costly
07:08 PM Emil: Because like LeoNerd already said, leads in contact with water dont work nicely together
07:34 PM cehteh: dip the finished circuit in epoxy
07:35 PM cehteh: if possible cure that then in a vaccum chamber, then all air bubbles come out
07:35 PM LeoNerd: And then white chocolate
07:35 PM cehteh: yum :)
07:35 PM LeoNerd: You can always sell anything for more if it's dipped in white chocolate
07:37 PM aczid: lol
08:23 PM LeoNerd: https://www.tindie.com/products/leonerd/atmega328pb-isolated-application-board/ More 328PB products :)
09:44 PM ub|k- is now known as ub|k
09:44 PM mindw0rk_ is now known as mindw0rk
09:45 PM zopsi_ is now known as zopsi
11:36 PM Tom_itx is now known as Tom_L
11:49 PM day_ is now known as daey