#avr Logs
Jul 16 2017
#avr Calendar
02:33 AM antto: cehteh they are exact, just printf() doesn't print them accurately for us humans to see
02:36 AM antto: ;P~
02:36 AM antto: floats are great, if you know how to deal with them
07:12 AM Emil: You know what's annoying
07:12 AM Emil: when you are doing filtering
07:13 AM Emil: And constantly running into overflow situations
07:13 AM Emil: Floats are nice then
07:13 AM Emil: It is annoying because even if the input and output values were 16 bit
07:14 AM Emil: the interminidiate values might be larger
07:14 AM martinux is now known as martinus
07:14 AM Emil: intermidiate*
07:15 AM Emil: I wonder if gcc treats << differently from 2*
07:15 AM Emil: And infers different promotion rulew
07:16 AM Emil: How can I know that my intermidiate results are working correctly?
07:16 AM Emil: Say I'm lowpass filtering
07:17 AM Emil: with y=(15*y1)>>4+x1>>4
07:21 AM Lambda_Aurigae: do the math with specific numbers on the chip and see what happens.
07:21 AM Lambda_Aurigae: you might need to add more ()
07:22 AM Thrashbarg: I used divides with one of my filters. GCC optimised it to shifts
07:22 AM Thrashbarg: though you'll want to check the disassembly
07:22 AM Thrashbarg: sign extend operations can get tricky with C
07:24 AM Emil: Lambda_Aurigae: I have used all the ()
07:25 AM Emil: It is annoying as fuck having to concern myself with overflow situations like these
07:26 AM Lambda_Aurigae: need more bits!
07:48 AM antto: moar!
08:17 AM Emil: Lambda_Aurigae: arm it is :D
08:46 AM julius: hi
08:47 AM julius: where would you ask a car radio / bluetooth / android question on irc?
08:52 AM Lambda_Aurigae: in places that talk about such things I would assume.
09:05 AM antto: with a combination like that.. #arduino
09:05 AM * antto runs
09:05 AM antto: or the espressif channel
09:15 AM Emil: julius: here?
11:50 AM JanC_ is now known as JanC
12:18 PM Lambda_Aurigae: 87degF outside and I get to build a new veggie stand today.
01:13 PM Emil: Hawt
01:13 PM Emil: Literally ;)
01:39 PM eszett: hi!
01:40 PM eszett: I have a question, I'd like to use "tag connect" with my Atmega32u4. Does the Atmega support SWD? Or do I need a special AVR-Tagconnect?
01:45 PM eszett: I'd like to use this http://i.imgur.com/i8Pk8XP.jpg
01:45 PM eszett: But AFAIK it's for SWD interface only
01:45 PM eszett: Does my Atmega32u4 support that?
01:48 PM Emil: Eh?
01:48 PM Emil: That's just a connector?
01:49 PM Emil: It's literally just an ISP alingment too with pogo pins
01:49 PM Emil: I should diy make my own
01:49 PM Emil: eszett: but no SWD
01:53 PM Lambda_Aurigae: Jartza used tag connect on the tagsu boards he made years ago.
01:54 PM Lambda_Aurigae: actual SWD is atmel arm only I think.
01:54 PM Lambda_Aurigae: AVR chips have different various debugging options.
01:55 PM Lambda_Aurigae: SWD appears to be an atmel arm jtag subset.
01:56 PM Emil: Lambda_Aurigae: eh?
01:56 PM Emil: SWD is like on every ARM
01:56 PM Lambda_Aurigae: tag-connect itself is just a physical interface.
01:56 PM Lambda_Aurigae: Emil, ok...I don't do a lot of arm, so,,,
01:56 PM Lambda_Aurigae: I'm working in the atmel realm.
01:57 PM Lambda_Aurigae: tag-connect can be used with pretty much any programmer so long as your programming pads on the board match what's coming through the cable and pogo pins
02:00 PM eszett: alright, that was an error in reasoning. This connector has 6 pins/pads, so I can just use them for JTAG
02:01 PM Lambda_Aurigae: yes
02:01 PM Lambda_Aurigae: if your chip supports it.
02:01 PM Lambda_Aurigae: or debugwire or whatever is supported on that particular chip.
02:02 PM Lambda_Aurigae: yup..that one has jtag.
02:04 PM eszett: the Atmega32U4 ye, very well!
02:15 PM Emil: eszett: no JTAG in m32u4 iirc
02:45 PM Lambda_Aurigae: datasheet says it has it
02:59 PM robinak is now known as robink
03:52 PM Emil: Oh it does
03:52 PM Emil: Nice
04:12 PM Jartza: Lambda_Aurigae: I actually don't use tag-connect :)
04:13 PM Jartza: https://cdn-c.verkkokauppa.com/images/66/2_266908-912x821.jpeg
04:13 PM Jartza: you can see the programming pads on lower left corner
04:23 PM Emil: Jartza: oh that's preeeetty nice
04:23 PM Emil: having it sold in Verkkokauppa
04:23 PM Emil: How did you manage?
05:08 PM Jartza: Emil: they asked if they could sell it
05:08 PM Jartza: but currently there's no stock of tagsu
05:08 PM Jartza: we're planning to make another batch, but probably that'll be the last one
05:08 PM Jartza: https://www.verkkokauppa.com/fi/product/61543/gcdns/Tagsu-elektroninen-nimilappu
05:09 PM Emil: Jartza: nice
05:11 PM Jartza: so we have sold around 400 of them :)
05:18 PM Jartza: maybe some crapperie selling all kind of gadgets would be better place
05:18 PM Jartza: like ebay
05:18 PM Jartza: verkkokauppa doesn't sell abroad
05:19 PM Jartza: dunno. next batch will be somewhere around 300-500
05:19 PM Jartza: haven't decided yet
05:25 PM Emil: Jartza: don't sell on eBay
05:25 PM Emil: not worth it
05:31 PM Lambda_Aurigae: Jartza, your own version?
05:33 PM eszett: Hi
05:34 PM eszett: Yes, the company "Tag-Connnect" even sells a cable for Atmel: TC2030-ICESPI-NL, and it's 60$, which is "slightly" expensive, even for a pogo pins cable..
05:34 PM eszett: or in other words, grossly overpriced
05:34 PM eszett: I found another solution now, which is not quite as professional, but still interesting.
05:36 PM eszett: it's called "solderless headers", costs 1.5$, here http://www.kr4.us/solderless-headers-10-pin-straight.html
05:36 PM eszett: you press it into the pads of the PCB and your done
05:36 PM eszett: what do you think of it?
05:41 PM eszett: here is the product catalogue of the manufacturer https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=0ahUKEwjBr_aR6I7VAhURZFAKHYlcAQ8QFghNMAk&url=http%3A%2F%2Fwww.autosplice.com%2Fwp-content%2Fuploads%2F2017%2F02%2FCompliant-press-fit-brochure-20170214.pdf&usg=AFQjCNEQFjmxro7k_mlEth642ee7gx76Kw
05:42 PM Emil: eszett: interesting
05:43 PM julius: Emil: hi....gonna ask tomorrow, need sleep
05:48 PM eszett: Emil, so I guess I'll buy rather those solderless headers for a buck, ok its not quite as sturdy and not for long term usage. But I won't flash or probe my MCU 400 times, but probably 5-10 times
05:48 PM eszett: not quite as professional compared to the Tag-Connect, I mean
05:56 PM Snert: What is the reason for Solder Freedom?
05:56 PM Snert: simply averse to soldering?
05:56 PM Emil: Snert: quick attach and detach
05:56 PM Emil: Snert: when soldering on a header is prohitive
05:57 PM Snert: it has the holes for a header. Therefore putting on a header seems right.
05:58 PM Snert: looks like a most excellent way to produce intermittent contacts.
05:58 PM Emil: Snert: it's not for permanent attachment
05:58 PM Emil: Snert: it's for momentary attachment when pogo pins are cumbersome
05:58 PM Lambda_Aurigae: I've always been a fan of edge connectors.
05:59 PM Snert: the IDC ribbon cable connector provides that part of it. Gut oh well.
06:00 PM Snert: assembly line testing seems like a good use case for that.
06:00 PM Snert: automated testing.
06:01 PM Emil: Snert: it's exactly for testing
06:01 PM Emil: those no solder headers are for when you need to test by yourself continuously
06:01 PM Emil: pogo pins when actually automated
06:03 PM Lambda_Aurigae: hmmmm...readymade 7 pin edge connectors! sata cables!
06:03 PM Lambda_Aurigae: or do they connect the GNDs internally?
06:04 PM Lambda_Aurigae: I need to check that.
06:08 PM eszett: When you scrill down to the user comments/ratings, it seems to be quite well rated: https://shop.pimoroni.com/products/gpio-hammer-header
06:11 PM eszett: Since I live in Europe I order from Pimoroni, rather than Sparkfun.
06:26 PM Emil: eszett: check out exp-tech.de
06:36 PM eszett: Emil, ye I browsed abit at exp-tech, they don't seem to stock solderless headers
06:37 PM Emil: It was more that if you rather order in Yurup then exp-tech is pretty good
06:41 PM eszett: Yurup =)
06:42 PM eszett: I once read about a land called "murica" and googled like half an hour until I got it
06:42 PM eszett: Emil, ye
06:45 PM Emil: eszett: yeah, there's no country called America
06:45 PM Emil: There's Murica though
06:56 PM Lambda_Aurigae: the Dysjointed States of Murica.
06:56 PM Lambda_Aurigae: or Dysfunctional
08:55 PM JanC_ is now known as JanC
10:40 PM day_ is now known as daey
11:01 PM day_ is now known as daey
11:50 PM day_ is now known as daey