#avr Logs
May 28 2017
#avr Calendar
01:25 AM polprog: Emil: it does i think, you need to specify it. and even if it doesnt you can type in the cycle amount too
01:29 AM polprog: oh
01:29 AM polprog: it's my b-day today :P
01:40 AM Casper: oh?
01:40 AM Casper: let me give you a gift!
01:41 AM Casper: polprog: http://i.imgur.com/GdZVnhA.jpg
01:41 AM Casper: a tiny gift for ya! ... of 1/4"
01:41 AM polprog: Casper: nice flowers :)
01:42 AM Casper: http://i.imgur.com/RMmTCW3.jpg <=== what about this?
01:43 AM polprog: theese grow in my backyard
01:43 AM polprog: cool
01:45 AM Casper: which one? both?
01:45 AM polprog: i think the first one is better
01:48 AM Casper: atleast... cause less nose issue
01:48 AM polprog: haha
01:49 AM Casper: http://i.imgur.com/RcCcDYD.jpg before it cause issue
01:50 AM polprog: i heard you can make a nice salad out of those
01:50 AM Casper: and pee in bed
01:50 AM polprog: why?
01:51 AM Casper: in french, they are called "pissenlit", which translate directly to pee in bed
01:51 AM polprog: rofl
01:51 AM polprog: didnt know that :P
01:51 AM timemage: Casper, i thought they were supposed to be a cure for that. along with everything else.
01:53 AM timemage: guess not, says diuretic.
01:53 AM Casper: yeah that's the word!
01:56 AM polprog: do avrs support DMA?
01:56 AM timemage: Casper, one one point i'd done something like a school report on them with another kid. i seem to remember he made up some quote and added it. this was something of a game the a couple of the kids played at the time, to see who could make the include the most outrageous crap in a report and not be called on it.
01:56 AM Casper: polprog: no, you will find DMA on processor, not microprocessor...
01:57 AM polprog: ok
01:57 AM polprog: i thought if i first generated a serie of bytes and out them ti ram, then in the next subroutine i'd read them out and send it would be DMA..
01:57 AM polprog: apparently it's not
01:58 AM timemage: Casper, hmm, i think some of the msp430 have what they call dma.
01:58 AM polprog: hey msp430 is 16 bit
01:59 AM timemage: polprog, is that bad?
01:59 AM polprog: no
01:59 AM polprog: just sayin
02:00 AM Casper: http://i.imgur.com/L0tB32r.jpg <=== that is an interessing pic
02:00 AM timemage: polprog, you were asking about the avr. the xmega have something they refer to as dma also
02:00 AM Casper: specially zoomed in
02:00 AM polprog: it's sharp
02:00 AM polprog: Casper:
02:00 AM Casper: that's my nick!
02:01 AM polprog: timemage: i just was thinking about how would i implement font in my crude t4313 board
02:01 AM polprog: and i misunderstood the dma
02:01 AM polprog: as a whole idea
02:02 AM polprog: i though it means when the code is taking things directly from mem via adress, instead for example via an array variable
02:02 AM timemage: polprog, was your idea different from automated byte shoveling?
02:02 AM polprog: let me google that
02:03 AM timemage: polprog, heh, that's just my crude description of dma.
02:03 AM polprog: ah
02:03 AM polprog: heh, that's why i got some pdf about excavators
02:03 AM polprog: :P
02:03 AM timemage: polprog, heh
02:04 AM polprog: as were talking im clicking around in wikipedia about microcontrollers and im surpirsed zilog made something called z8, which doesnt share anything in common with z80
02:04 AM polprog: i actually have a book about z80
02:05 AM timemage: polprog, i think the z8 was their own design.
02:05 AM polprog: yeah it was
02:16 AM xentrac: is it any good?
02:16 AM polprog: what? the book?
02:16 AM xentrac: the z8
02:17 AM polprog: no idea
02:36 AM rue_bed: you guys dont know what dma is?
02:37 AM rue_bed: a dma transfers data for the microprocessor
02:37 AM timemage: rue_bed, you didn't like my description i take it. =)
02:37 AM rue_bed: aka io->memory, memory->memory, or memory->io
02:38 AM rue_bed: you set them up for a transfer and they do their thing when triggered
02:38 AM rue_bed: it can be to just write a byte to somewhere, or move a block
02:39 AM rue_bed: so, say you have a processor that would incurr 3 wait states to write to an io port,
02:39 AM rue_bed: you can put your data in memory and have the dma do the move via a timer
02:39 AM rue_bed: lots of things depend on the hardware, but thats a jist
02:40 AM rue_bed: also good if say you want to sample an adc channel without microprocessor speed limits or overhead
02:40 AM rue_bed: you can have the dma use a timer to transfer data from the adc to a block of memory
02:40 AM rue_bed: typically you would see a flag or interrupt when its done the cycle it was set up for
02:40 AM timemage: rue_bed, that's part of why i bothered to mention the msp430.
02:41 AM rue_bed: xmega is silly, just use ARM
02:41 AM timemage: rue_bed, it's silly if you're not looking to see if there's an avr with dma support.
02:44 AM xentrac: :)
06:53 AM Lambda_Aurigae: timemage, there are some new ones with semi-dma....and the xmega series has it.
06:55 AM Lambda_Aurigae: traditional atmega and attiny do not have dma.
06:56 AM Lambda_Aurigae: rue_bed, with dma properly implemented you don't even need a timer...your adc channel can generate an interrupt that triggers the dma to transfer data from the adc to memory.
08:48 AM jaakkos: if COM bits in the TCCR1A register are pulled down, is it guaranteed the pins that were PWM-driven are pulled low immediately?
08:50 AM jaakkos: or is it possible that some pulse still comes after the write :I probably not possible
09:53 AM Emil: polprog: Hyvää syntymäpäivää! :)
09:53 AM Emil: polprog: also dma is when a peripheral does it for you without interrupting execution
09:55 AM Emil: and mcus can have dma just fine
09:55 AM Emil: dunno what the fuck others are about here :D
09:56 AM tpw_rules: Emil: i don't think any 8 bit AVRs have dma tho
09:56 AM tpw_rules: (i imagine that was the point)
10:07 AM Emil: tpw_rules: that's true
10:18 AM NoHitWonder^: 8-bit STM8 micros do have it though
10:19 AM specing: at 1/10 the price
10:43 AM Emil: yeah
10:46 AM specing: well AVRs are only going to get mroe epxensive now that microchip has to repay the atmel purchase
10:55 AM rue_house: I'm trying to get the stm32 thing going
11:07 AM Tom_L: having problems with it rue?
11:07 AM Tom_L: /j #stm32
11:08 AM specing: Tom_L: then rue will have two problems
11:08 AM Tom_L: are they jerks there?
11:08 AM specing: I heard they were
11:09 AM Emil: Tom_L: that channel is känser
11:10 AM Tom_L: what about edev?
11:10 AM Tom_L: that was started when the hammer came out iirc
11:12 AM Tom_L: http://elinux.org/Hammer_Board
11:13 AM Tom_L: maybe it is elinux now
11:13 AM Tom_L: #
11:15 AM Tom_L: rue_bed, get an early start and you can run your christmas lights with it: https://www.youtube.com/watch?v=revJ7Kccufg
11:19 AM Tom_L: https://www.flickr.com/photos/21836722@N02/sets/72157603459882107/with/2110566815/
01:18 PM polprog: Emil: the whole discussion was caused by me not making sure what dma is before asking :P
01:25 PM polprog: i may write a solitaire on AVRs if i get my hands on a nice graphic display
01:55 PM timemage: Lambda_Aurigae, what does the "semi-dma" refer to?
03:23 PM Lambda_Aurigae: it refers to a limited dma...from what I have read.
03:26 PM Emil: you can do dma in many ways
03:26 PM Emil: the ultimate dma is one that can access memory without caring about the system bus
03:26 PM Emil: usually dma accesses memory when the main processor is not accessing it
03:26 PM Emil: there are multiple ways to it
03:26 PM Lambda_Aurigae: yup
03:27 PM Emil: iirc xmega dma had the lazy and aggressive versions
03:27 PM Emil: So either access memory when processor is not using it or reserve the bus when sees fit
03:55 PM JanC_ is now known as JanC
04:31 PM polprog: i noticed that when compiling my asm code with avr-gcc the assembler is generating errors when i try to use registers lower than 16...
04:31 PM polprog: am i doing something wrong?
04:31 PM Emil: polprog: yeah you can't use all instructions with all the registeres
04:32 PM polprog: oh
04:32 PM polprog: i didnt know that
04:35 PM Lambda_Aurigae: read
04:35 PM Lambda_Aurigae: the
04:35 PM Lambda_Aurigae: manual
04:35 PM Lambda_Aurigae: hehe
04:35 PM polprog: hehe, the part datasheet or an appnote?
04:35 PM polprog: i thought it was avr-gcc problem at first
04:35 PM Lambda_Aurigae: actually, in this case, the instruction set
04:35 PM polprog: thanks
04:35 PM polprog: i have it
04:35 PM Emil: Lambda_Aurigae: showing restrain ;)
04:36 PM Lambda_Aurigae: I am?
04:36 PM polprog: night o/
04:36 PM Emil: yeah
04:36 PM Emil: polprog: good night
07:04 PM Tachyon` is now known as Tachaway
08:26 PM _habnabit: okay so i'm reading through http://www.nongnu.org/avr-libc/user-manual/mem_sections.html and it mentions the .initN sections but what actually puts them in that order? a linker script? i'm trying to figure out how to make sure __do_copy_data gets called, and i'm using -Wl,-u,__do_copy_data, but gcc is inscrutable and i can't figure out why it wasn't included
08:29 PM _habnabit: oh of course it's in binutils
08:29 PM _habnabit: why is it in binutils.
08:29 PM tpw_rules: cause that's where the linker is?
08:29 PM tpw_rules: i think
08:29 PM _habnabit: it is where ld is
09:26 PM rue_house: do you need to know how to call the utilites to manually compile a program?
09:27 PM theBear: dial 0 and ask the operator to connect you, then err, ask them ? :)
09:31 PM Casper: hey dasbear!
09:32 PM Lambda_Aurigae: _habnabit, binutils...utils for generating binaries for the particular architecture...in this case, avr-binutils.
09:34 PM theBear: Casper, gutenmorgen, das spectre
09:34 PM Casper: http://i.imgur.com/L0tB32r.jpg
09:35 PM theBear: ich bin aiiight, you been aiight ? <grin> i love butchering languages i barely know
09:40 PM Casper: ya I'm ok
11:39 PM day__ is now known as daey