#qi-hardware IRC log for Monday, 2013-08-26

DocScrutinizer05lol! 02:27
DocScrutinizer05>> [2013-08-25 19:56:06] <patchvonbraun1> bounce: But to be honest, these dongles are just fine for radio astronomy, provided you have adequate filtering in front of them, and some low-noise gain.  Which you always need anyway02:28
DocScrutinizer05>> [2013-08-25 19:56:33] <patchvonbraun1> bounce: I'm using a plethora of dongles on the SBRAC dish02:28
whitequarklol indeed02:29
DocScrutinizer05the dongle:  http://sdr.osmocom.org/trac/wiki/rtl-sdr   The dish: http://www.sbrac.org02:30
wpwrakand thus SETI (Summoning of ExtraTerrestrIals) enters an entirely new phase ...02:38
cdeDocScrutinizer05 :)07:27
paul_boddieHello! Does anyone have any opinions/experiences with the nanosleep system call on the NanoNote?16:37
paul_boddieIt doesn't seem very "nano", but I wonder if the NanoNote is fast enough to notice any intervals at that level.16:39
larscnano is GHz16:40
paul_boddieIndeed.16:41
paul_boddieEven hundreds of nano - tenths of micro - are probably asking a bit much from the poor Ben.16:41
paul_boddieI think the call itself is probably expensive enough to burn up any delay of that order.16:42
larscyes16:42
paul_boddieSo I guess I should ask what the best way is to put delays into NanoNote programs.16:43
larsci = 100; while(--i);16:43
larsc;)16:43
paul_boddieI've been doing I2C stuff, and without any delay I manage to race ahead of the slave unless I do an empty for loop. :-)16:43
larscI'd let the kernel handle I2C stuff16:44
paul_boddieI haven't really had this problem with SPI stuff before now.16:44
paul_boddieCan the kernel coordinate I2C stuff over the 8:10/MMC port?16:44
paul_boddieI saw that wpwrak had done some SPI drivers which I should perhaps be looking at for my SPI experiments. (Or maybe I misremember.)16:45
mthif you configure the pins as plain GPIO pins, you should be able to use the i2c-gpio driver with them16:45
mthconfigure -> making sure no MMC driver claims them is probably enough16:46
paul_boddieThanks, mth! I suppose the only disadvantage that I can think of is that I'm then forced into "driver space".16:46
mthyou can send I2C messages from user space16:46
mthwith only the bitbanging done in kernel16:47
mthsee the i2c-tools package16:47
paul_boddieUseful to know, thanks! If I ever get to the point of wanting to migrate some of this into a driver, it'd be a nice first step.16:48
paul_boddieI guess it is this: http://www.lm-sensors.org/wiki/I2CTools16:50
paul_boddieAnd this: http://elinux.org/Interfacing_with_I2C_Devices16:50
mthyes16:51
mthhere is an example of the configuration of the kernel side: http://projects.qi-hardware.com/index.php/p/qi-kernel/source/tree/jz-3.9/arch/mips/jz4740/board-a320.c16:53
mthsearch for "i2c"16:53
mthspecifically, for CONFIG_I2C_GPIO16:54
paul_boddieIs this a recent kernel thing?16:55
mthno, it has been there a few years at least16:57
paul_boddieMaybe I have to dig a bit more in my kernel sources.16:59
paul_boddieAh, I see it now!16:59
paul_boddieThanks for the help once again! :-)17:16
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