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Tin Gang posted:mathetical proofs are not equivalent to laws of physics!!!
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Feb 1, 2015 19:35
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| # ? May 15, 2024 12:23 |
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1+1=0 in GF(2)
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Feb 1, 2015 19:50
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Barnyard Protein posted:1+1=0 in GF(2) more generally, x+x = 0 in GF(2^n) for any x, n
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Feb 2, 2015 02:50
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I made an LED blink on a breadboard via jumpers from the Edison Arduino board. and the LED didn't get hot or explode! I actually used a resistor, and the right resistor too! next I want to measure just how fast I can toggle that I/O from Lisp and C. I just didn't want to set up the logic analyzer before dinner. it was getting to be cheesesteak o'clock, you see.
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Feb 2, 2015 06:50
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is that all sarcastic or why do you own a logic analyzer if making an led turn on is a big deal
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Feb 2, 2015 07:02
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it's somewhat sarcastic as my teenage adventures in hardware were less than successful and half a lifetime ago now though I want it to not be a big deal. I want to make things that plug into other things, and I want to make things what do things. and well  blink baby blink! and in C instead of Clozure Common Lisp:  both are using libmraa via sysfs rather than memory-mapped I/O eschaton fucked around with this message at 07:39 on Feb 2, 2015 |
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Feb 2, 2015 07:31
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its so loving weird going from computers that have gigabytes and gigabytes of RAM and terabytes of hard drive space to cursing that your program is 128 bytes shy of fitting in your little 16bit micro controller somehow it fits with -O4 which is using a kilobyte less space than -O3. either ti is magic or its just randomly cut out parts of my code 
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Feb 2, 2015 23:48
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whats the compiler? gcc doesnt even have an O4
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Feb 3, 2015 01:30
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its ti's msp430 compiler
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Feb 3, 2015 15:15
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they use mspgcc now don't they
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Feb 3, 2015 15:17
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its included in CCS 6; my options for compilers are TI v4.4.2, TI v4.3.3 and GNU v4.9.1
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Feb 3, 2015 15:23
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idk read a help or man page i guess? or have it emit the assembly and/or disassemble it and see what's different!
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Feb 3, 2015 16:02
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'look at the asm' is always the right answer. in cases where it doesn't seem to be the right answer, you're asking the wrong question.
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Feb 3, 2015 16:04
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Blotto Skorzany posted:'look at the asm' is always the right answer. in cases where it doesn't seem to be the right answer, you're asking the wrong question. yeah, i know, i was more tearing my hair out at being just over on flash
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Feb 3, 2015 16:28
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should i get this y/n http://www.amazon.com/Rigol-DS1052E-Digital-Channels-sampling/dp/B003MYND5A
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Feb 3, 2015 16:34
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Chill Callahan posted:should i get this y/n http://www.amazon.com/Rigol-DS1052E-Digital-Channels-sampling/dp/B003MYND5A fancy fancy, look at me here looking for my first multimeter. moving past simple arduinos and need a good multimeter for more in depth microcontroller projects. how does the fluke 115 (http://amzn.com/B000OCFFMW) fair?
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Feb 3, 2015 23:32
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Chill Callahan posted:should i get this y/n http://www.amazon.com/Rigol-DS1052E-Digital-Channels-sampling/dp/B003MYND5A p sure rigol was recommended to me back when i was asking around for cheap, decent scopes then i bought this instead 
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Feb 3, 2015 23:40
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Yeah at the same time I really want a Tek 2465 but also dealing with repairs on something that old is a pain.
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Feb 4, 2015 00:22
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Chill Callahan posted:should i get this y/n http://www.amazon.com/Rigol-DS1052E-Digital-Channels-sampling/dp/B003MYND5A that is a good low-end modern dso, yes. it will do your needful xilni posted:fancy fancy, look at me here looking for my first multimeter. moving past simple arduinos and need a good multimeter for more in depth microcontroller projects. the fluke 115 is good (it is a fluke after all) but the thing you'll miss is a milli-/micro- amp range. you wont find both a small and a large current range on a fluke until you get to the 177/179 at like $250-$275. mA range measurements are probably going to be your most common current measurement as a hobbyist, and also the range missing from the brand name's low end meters (looking at you Agilent U1232A/Fluke11X). I'd look on the used market, fluke/agilent meters are very very stable and used will be pretty much as good as new
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Feb 4, 2015 00:42
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Arcsech posted:the fluke 115 is good (it is a fluke after all) but the thing you'll miss is a milli-/micro- amp range. you wont find both a small and a large current range on a fluke until you get to the 177/179 at like $250-$275. mA range measurements are probably going to be your most common current measurement as a hobbyist, and also the range missing from the brand name's low end meters (looking at you Agilent U1232A/Fluke11X). I'd look on the used market, fluke/agilent meters are very very stable and used will be pretty much as good as new that seems to be the most recurrent concern with the fluke 11x series and why i've held off so far. when your typical led draws 20mA max i can see i'd need mA. off to check the used market
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Feb 4, 2015 05:33
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 guys there's something wrong with my bits
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Feb 4, 2015 19:50
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Chill Callahan posted:Yeah at the same time I really want a Tek 2465 but also dealing with repairs on something that old is a pain. mine has been sitting around, broken, for about a year "idk anything about tubes and poo poo but i could use a project!" i said, happily handing twenty dollars to Mr. Craiglist i have a problem
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Feb 4, 2015 19:56
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someone recycled this thing, is it any good
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Feb 6, 2015 19:12
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depends on your definition of "good"
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Feb 6, 2015 19:13
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http://www.barrytech.com/tektronix/vintage/tek564.html
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Feb 6, 2015 19:15
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atomicthumbs posted:someone recycled this thing, is it any good does it work?
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Feb 6, 2015 19:17
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As a Millennial I posted:does it work? it makes cool waveforms when I play aphex twin into it and the storage function sort of lets me use it as the world's heaviest etch-a-sketch
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Feb 7, 2015 05:52
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atomicthumbs posted:someone recycled this thing, is it any good My dad had one of those, no idea where it went after he died.
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Feb 7, 2015 05:52
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 if I specced these out wrong BOY am I gonna look really stupid
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Feb 10, 2015 16:41
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those are some expensive caps what are they
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Feb 10, 2015 18:00
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Bloody posted:those are some expensive caps what are they CDE Film Capacitors can't you read???
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Feb 10, 2015 18:57
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I'm doing firmware for a lil battery powered wireless sensor it has a 1.5F supercapacitor on it for some reason  makes power cycling more of a pain than it needs to be
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Feb 10, 2015 19:13
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Mr Dog posted:I'm doing firmware for a lil battery powered wireless sensor sounds like it's actually supercapacitor powered now doesn't it
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Feb 10, 2015 19:15
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Mr Dog posted:I'm doing firmware for a lil battery powered wireless sensor put a relay in series with the supercap imo
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Feb 10, 2015 19:22
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i mean as far as i can tell it's there to smooth out the shock of the radio switching on and transmitting because the power consumption blips up from 300 uA to 10 mA for a fraction of a second, they only overspecced the necessary capacitance for that by uuh like six orders of magnitude or so nbd did i mention the BOM cost is supposedly a major consideration on this board too and anyway, instead of smoothing out the current spike it probably causes a Tohoku-scale inrush when you first plug the batteries in so it doesn't really seem like a win to me. like i'm pretty sure this thing would arc if alkaline battery chemistry were capable of it hooking this thing up to a benchtop PSU current-limited to 100 mA it takes like three seconds for the current limiter to disengage, in the meantime the voltage rises up to 3V from a starting value of something like 1.4 (i am a software guy, not a hardware guy. i know like ohm's law and vaguely how capacitors are used and that's about it)
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Feb 10, 2015 19:32
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yeah iirc 1-wire devices leech power from the bus during downtime and their energy cap is measured in nF i think
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Feb 10, 2015 19:36
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The BOM cost is really important for this project so we're giving you the cheapest and shittiest microcontroller we can find with not nearly enough ROM when $1 Cortex-M0 chips with 64KB of program ROM are a thing that exists *plans to ship 10,000 units* At least it isn't a PIC
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Feb 10, 2015 19:39
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Mr Dog posted:and anyway, instead of smoothing out the current spike it probably causes a Tohoku-scale inrush when you first plug the batteries in so it doesn't really seem like a win to me. like i'm pretty sure this thing would arc if alkaline battery chemistry were capable of it lol definitely. i'd almost be worried about popping alkalines if you power cycle it too frequently, they don't like big ol' current spikes that much especially when they've been run down a ways
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Feb 10, 2015 20:01
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Bloody posted:those are some expensive caps what are they they are caps that can handle super high frequencies/high voltages for a tesla coil. if the thing gets an hour of run time before something burns out I'm calling it a victory
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Feb 10, 2015 21:16
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| # ? May 15, 2024 12:23 |
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Mr Dog posted:i mean as far as i can tell it's there to smooth out the shock of the radio switching on and transmitting because the power consumption blips up from 300 uA to 10 mA for a fraction of a second, they only overspecced the necessary capacitance for that by uuh like six orders of magnitude or so nbd it's a wireless sensor you said -- you sure it's not there to enable the thing to store some values to EEPROM or do a graceful shutdown for some reason when power is cut?
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Feb 10, 2015 22:28
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