#robotics Logs

Feb 28 2012

00:14 rue_house can retorical questions have retorical answer?
00:14 rue_house s
00:16 katsmeow-afk yeas, if the point is to have rhetoric
00:17 rue_house huh
00:17 katsmeow-afk ask any politician anything, you'll get in return vast magniloquence
00:18 katsmeow-afk "In the absence of blue light, the flies do not respond to a magnetic field.
00:18 katsmeow-afk "
00:18 rue_house ...
00:19 rue_house it implies they do when there is
00:19 katsmeow-afk yeas, and it's after midnite, my brian switched off, so i dunno how to make cents of thayat
00:19 rue_house direction detection by sprectrum shift, interesting idea
00:20 katsmeow-afk in what way is it interesting?
00:20 katsmeow-afk "�Homing pigeons become disoriented when magnets are placed at the sides of their head. However, this disorientation occurs only on cloudy days"
00:20 rue_house I'm intested to know if blue light is effected by magnetic fields
00:20 rue_house otherwise they use the big bright thing
00:22 katsmeow-afk "However, magnetism can alter the state of polarisation of light."
00:23 rue_house I wonder if flies operate with polorized light
00:23 rue_house that might be an interesting experiment
00:24 rue_house ok I'm falling asleep
00:24 rue_house I think I transfered the pcb pattern for the overload
00:24 katsmeow-afk how will you use this data?
00:24 rue_house board
00:25 rue_house I'll tag it with keywords and tuck it away
00:25 rue_house It'll stay idle until a search is done with similar keywords
00:26 rue_house its like that peice of odd-ball sized angle iron, you tuck it away for that special project that it perfectly fits
00:27 rue_house course, when that special project comes along, its an inch too short, so you use soemthing else
00:27 tsmeow-afk
00:28 rue_house till one day you find it, too rusty to be of use for anything, and you curse yourself for not having *just used it* for *anything*
00:28 katsmeow-afk "Some users have reported missing words in the text. This seems to be caused by our dictionary "pop-ups" not being compatible with other software installed on some computers. If you notice words missing from the text, please try viewing the page from a different browser or from a different computer.
00:28 katsmeow-afk "
00:28 rue_house and put it in the 'its gonna be garbage if I dont find a use for it by the time after next I take the garbage out" pile
00:29 katsmeow-afk nonono
00:29 katsmeow-afk because after the garbage is gone, you'll haveto go buy it aain
00:30 rue_house I meant the one you happened upon and thought it perfect for soemthing special
00:30 katsmeow-afk At the quantum level, an effect known as Delbruck scattering can occur
00:30 katsmeow-afk where it is thought that an extremely powerful EM wave can break a
00:30 katsmeow-afk photon down into an electron and a positron, both of which do carry a
00:30 katsmeow-afk charge and can therefore have their paths altered by an EM field.
00:31 rue_house the one you bought is still with the other 5 you bought cause you felt you never had enough, you didn't use it for the project you were gonna and you havn't had a project since that its usefull for
00:31 katsmeow-afk i wanna know how i can modulate light with an electric signal
00:31 katsmeow-afk at ghz speeds and cheaply
00:31 rue_house :)
00:31 katsmeow-afk linearly, with at most 3% distortion
00:32 rue_house I just used a LARGE set of lcd shutters for paralllel input to my optic computer
00:32 katsmeow-afk but lcd are sllllooowwwww
00:32 rue_house large parallel
00:33 katsmeow-afk but you cannot operate them at Mhz speeds, and i said Ghz
00:49 katsmeow-afk http://www.drexel.edu/now/news-media/releases/archive/2012/February/Engineering-Research-Brings-Seven-Humanoid-Robots-to-Drexel/
00:51 katsmeow-afk http://www.drexel.edu/now/news-media/releases/archive/2012/February/Humanoid-Robot-Exhibition-Opens-Drexel-Engineers-Week/
00:53 theBear how the fuck is 4'3" adult-sized ?
00:54 tsmeow-afk sh
00:54 theBear i agree
00:54 katsmeow-afk i don't know ANY cats that tall
00:54 theBear :)
01:28 katsmeow-afk is there any material that is self-reversably changeable, in any way, on it's surface, by putting it in a vaccuum and hitting it with a modulated electron beam?
01:29 theBear what is self-reversably changeable mean ?
01:29 katsmeow-afk meaning the electron beam can change it, without permanent change
01:29 theBear but change it how ?
01:30 katsmeow-afk like in a crt the electron beam turns on a phosphor, it turns off when the beam is stopped, it doesn't stay on permanently
01:30 theBear ok, how about phosphors then ?
01:30 katsmeow-afk ini my question, i mean ANY change, physical movement on an atomic scale, molecular scale, color change, etc
01:31 theBear hmm... you talking visual, or just changing in any way ?
01:31 katsmeow-afk i don't want the material to *emit* light
01:32 katsmeow-afk i'd measure the material thru the glass, using photography and lasers
01:32 theBear well phosphors should still work, maybe a fet with an exposed junction, or just plain blasting electrons at the gate
01:32 duckinator i'm curious, what would you be doing with this? :P
01:32 theBear hmm... .MAYBE some kinda quartz/piezo thing ?
01:32 katsmeow-afk how would blasting electrons an a hunk os silicon change the phisical silicon?
01:32 katsmeow-afk heys duck!
01:32 duckinator hey kat
01:33 theBear it wouldn't change it physically, but you didn't say visual until after i said that
01:33 katsmeow-afk oh
01:33 theBear tubes/valves can move in sympathy with signal, not exactly sure why
01:33 katsmeow-afk at tis point, until i fnd a material that will undergo some change, i don't know even how wide or strong the electon beam would be
01:34 katsmeow-afk hmm, microphonic valves
01:34 theBear yeah, that's what we used to call 'em when it got beyond a joke
01:34 katsmeow-afk same way electrostatic headphones/speakers work, i imagine?
01:35 theBear mmm, that'd make snes
01:35 katsmeow-afk no wonder i cannot spell, it's 1:25am
01:35 theBear in which case you could build an 'array' of them in theory, if that's what yer heading for
01:36 katsmeow-afk not what i am looking for tho, for one thing, the elements are too slow, and i wanna use a smaller beam than the plate of a 12AX7
01:36 theBear i meant build your own 'tube'
01:37 theBear and there are MUCH smaller tubes than ax7's around
01:37 katsmeow-afk yeas
01:37 katsmeow-afk but i've never heard of anyone taping a mic to the face of a crt to hear the electrons hitting the screen
01:38 katsmeow-afk i don't necessarily want to hear anything anyhow
01:38 theBear but you aren't using a mic ?
01:38 theBear micrphonic tubes are microphonic 'cos the metal inside is moving, not the glass
01:38 katsmeow-afk yeas, but the reason you hear a microphonic tube is the vibratons goto the glass thru the supports
01:39 theBear usually you hear it thru the output/signal, thus the term microphonic and not speakerphonic
01:39 duckinator kat, wouldn't basically any piezoelectric material respond to an electron beam by moving in some manner? or am i missing something here?
01:39 katsmeow-afk and the reason you can thump your woofers when you tape the tube with a pencil is the vibrations goto the elements thru the supports
01:39 theBear but my point is that the metal is moving
01:40 katsmeow-afk bear, yeas, but the metal will not move if i shoot a 100mhz electon beam at it
01:40 theBear moving thru electronic stimulus
01:40 theBear maybe not 100mhz, in those tubes, but smaller metal, custom tube could
01:41 katsmeow-afk duck, true, i don't know if quartz (the usual piezo stuff) is speed limited
01:41 tsmeow-afk pon
01:41 theBear you can make an electron scanning microscope with quartz/piezo
01:42 theBear can't be THAT slow
01:42 katsmeow-afk what part is made with the quartz?
01:42 theBear the piezo disc, you take one from an old watch or something
01:42 theBear score it up, x-y piezo disc
01:43 katsmeow-afk i have an electron gun in a high speed crt that's got damaged deflection plates, i am thinking i should use it for something interesting, not throw it away
01:43 katsmeow-afk bear, what's the piezo disk DO tho?
01:44 theBear katsmeow-afk, it directs the scanning action of the electron-tip-thingy
01:45 katsmeow-afk oh, then it can be dead slow
01:48 katsmeow-afk In 2009, it was shown that T-waves are produced when unpeeling adhesive tape. The observed spectrum of this terahertz radiation exhibits a peak at 2 THz and a broader peak at 18 THz. The radiation is not polarized. The mechanism of terahertz radiation is tribocharging of the adhesive tape and subsequent discharge.[4]
01:48 katsmeow-afk In 2011, Japanese electronic parts maker Rohm and a research team at Osaka University produced a chip capable of transmitting 1.5 Gbps using terahertz radiation.[5] It is unknown how much adhesive tape was used.
01:48 theBear heh
01:55 katsmeow-afk ah, praps a "Pockel cell" would work
01:59 katsmeow-afk nope, the electrons haveto flow the same axis as the light, photographing it would be impossible
02:08 katsmeow-afk hmm, 50ps responce at 6.5kv
09:16 rue_house http://www.marginallyclever.com/2012/02/linear-interpolation-vs-trapezoid-motioninterpolation/
09:16 rue_house Aggrav8ted is going to share that link with us soon
09:17 rue_house my code seperates out the synchonization of the axies from the velocity profile used for them
09:17 rue_house I can sync almost any number of axies
09:20 rue_house maybe someone can point out to agg that the calc for t4 has a typo, 'max' looks like it should be 'vmax'
09:21 rue_house and that he dosn't need to calculate it with division seeing as the accel and de-accel time will be the same
09:21 rue_house oh my
09:22 rue_house he calls this whole thing for every step
09:22 rue_house ah no
09:22 rue_house good
09:23 rue_house no he does
09:23 rue_house this calculates the speed at the current location
09:23 rue_house eeek
09:23 rue_house 'brensham'
09:24 eBear slaps
09:24 rue_house or just floating point
09:24 theBear get a hold of yourself man !
09:24 theBear order your thoughts
09:24 rue_house order my thoughts
09:24 rue_house I 'm gonna think about that today
09:24 theBear hehe
09:25 theBear you ever seen a delta-sigma a-d and d-a (in this case a delay) based on a couple of flipflops ? i think it's a pretty cool idea
09:25 rue_house "yes, I'd like 20 mins of the meaning of life followed by 40 mins of how to leave the planet."
09:25 rue_house I know delta-sigma, flipflops?
09:25 rue_house done how?
09:25 theBear yeah, umm, lemme find the schem
09:26 theBear http://elm-chan.org/works/srp/srp.png
09:26 theBear just the middle bit really
09:27 rue_house I wonder why agg didn't use a structure to pre-plan the motion profile so he wouldn't hav to do all that math every step of the way
09:27 theBear isn't he one of those crazies that never makes sense ?
09:28 rue_house they dont time it cuase they dont need to
09:28 rue_house huh
09:29 rue_house dram mux ciruit too
09:29 rue_house COOL
09:30 theBear that's what i said :) glad someone else appreciates it
09:30 rue_house put an avr on there and time the adc pulses
09:31 rue_house too bad they dont ahve the VCO I want to make in there too
09:32 rue_house for the clock
09:32 theBear clock ? like err, what kinda clock ?
09:32 rue_house the clock into the 164
09:32 rue_house for variable delay
09:33 theBear i mean you wanna make ?
09:33 rue_house I like how they do "stereo" :)
09:33 rue_house I want to make a high freq vco
09:33 rue_house I fianlly found some varicaps
09:33 theBear it's a "matrix surround decoder" .... technically that's how 'stereo' should be done
09:34 theBear as time goes on, i like the effect, much more subtle and adjustable than 'real' surround, the guys that mix those movies are asses
09:34 rue_house *sigh* I'm late for work again
09:34 theBear don't feel bad, i don't have a job again (well still, but you know, days come and go)
09:35 theBear meh, cartoon time
12:24 katsmeow-afk wait, i thought all you guys were against all drams
12:25 katsmeow-afk "too slow" , "too complicated" , "why bother if you can use statics" , etc
12:30 Steffanx So, how long do i have to wait?
12:31 katsmeow-afk not sure, i really don't know the protocol
12:31 katsmeow-afk i know "dram", not "human"
12:31 Steffanx me neither, but you said "wait"
12:31 katsmeow-afk yeas, it's a social convention
12:31 Steffanx Oooh
12:32 Steffanx SRAM is too expensive, so i prefer SDRAM :)
12:33 Steffanx or psram
12:33 Steffanx Which is ok-ish, but pretty much bga only
12:34 katsmeow-afk dram with a self-refresh pin is psram or not?
12:35 Steffanx dram with self-refresh indeed
12:37 katsmeow-afk i have 1000's of dram chips with self-refresh, and humans laughed at me for wanting to use them on avr because of the refresh requirement,, it's merely a matter of toggling ONE PIN when the avr is off not accessing memory that cycle
12:37 katsmeow-afk humans keep me in a constant state of confusion and amazement
12:38 Steffanx I wouldn't use extra S-/DRAM with avr's anyway :)
12:39 Steffanx Or maybe with the xmega family, which has it's only external memory controller :)
12:39 Steffanx *only = own
12:40 katsmeow-afk several avr have external memory access built in, especially those 8086-compatable
12:40 Steffanx Using a weird 'xmem' interface?
12:40 katsmeow-afk no
12:41 katsmeow-afk has four 8-bit ports, 3 of them used natively for external ram or memory-mapped devices or general purpose io ports
12:41 Steffanx Hmm, AVR's have that?!
12:42 tsmeow-afk found some thin air to grab a part number from : AT90S
12:43 Steffanx Oh, I can't call that one an AVR :P
12:43 katsmeow-afk having external memory acces in avr goes back at least as far as some parts are obsolete due to "age"
12:43 katsmeow-afk why not?
12:43 Steffanx "This device was obsoleted in year 2000!" .. was 'before my time'
12:44 Steffanx I didn't even know what an AVR was back in 2000
12:44 katsmeow-afk it's still supported by programmer boards and compilers
12:44 tsmeow-afk drops her agruement because she doesn't wanna argue, or find newer part num
12:45 Steffanx :P
12:45 Steffanx I guess katsmeow-afk is one of those oldies :P
12:47 katsmeow-afk i remember when the 8086 was new
12:47 katsmeow-afk the stupid arguements over which was better, the 6809 or the 6502
12:48 katsmeow-afk laughing at the 8085 and the 80186, and drooling over the latest 80x87, and anything put out by Cypress
12:49 katsmeow-afk wondering why anyone would used MC14xxxx parts in anything not battery powered, or how advertising CD40xxx parts as "high speed" was legal
12:51 Steffanx My time goes back to the 'period' people argued about which is better .. PIC or AVR :P
12:51 Steffanx Oh no, we're still IN that period
12:51 katsmeow-afk back when if you put 10 Commodore 64 in a cluster, and sold it to the ussr, you could be arrested and convicted of treason for selling high end computer equipment to the enemy
12:52 katsmeow-afk the availabilty of high end test equipment was a state secret, but you can buy it now on ebay for pennies on the dollar
13:06 katsmeow-afk i discovered that contrary to propaganda, Tektronix didn't make the world's fastest oscope, a French company did, altho it's screen draw repitition rate was limited because it was primarily destined to be a single-shot digitiser oscope
13:07 katsmeow-afk it was rated 6 Ghz in the 1980's, the Tek 7104 was 1 Ghz, and Tek sold a rebranded version of the French scope, but apparently not very actively or publically
13:07 katsmeow-afk it also cost $100,000 or more, and weighed 130lbs
13:10 Steffanx Yay
13:10 tsmeow-afk celebrates
15:28 katsmeow-afk [ChanServ PING reply]: 50 secs
17:09 noodle Any EE guys in here?
17:10 LoRez nope
17:10 LoRez did you have a real question?
17:11 noodle question about voltages
17:11 noodle needed 6v dc in,
17:11 noodle have a 7.5v thing,
17:11 noodle whats the risk of overvolting?
17:12 katsmeow-afk lol
17:12 katsmeow-afk not enough data
17:12 LoRez regulated 7.5v thingy or unregulated?
17:12 LoRez what's the device?
17:13 noodle KVM switch
17:13 noodle needs a 6v transformer
17:13 katsmeow-afk transformers do not output dc
17:16 katsmeow-afk i sugget you get a 6vdc regulated walwart for the kvm, possibly Radio Shack or Ebay, or maybe Walmart
17:16 tsmeow-afk rubs her sore paws, after typing in long strings of digits to FedEx, USPS, and UPS for lost packages trackng num
17:21 tsmeow-afk shuts up, sits back, and lets noodle keep asking around till he gets the answer he w
17:21 katsmeow-afk oh, he left
17:22 katsmeow-afk i do not understand the quit message
17:39 katsmeow-afk Tom, dear Tom, sir? if you pay over $2.66 on your GTLP8T306MTC , i can save you money on those also
17:41 katsmeow-afk that includes s&h
17:43 Tom_itx my what?
17:44 katsmeow-afk GTL translator chips
17:44 Tom_itx GTL2003PW
17:44 Tom_itx .52
17:45 katsmeow-afk 8bit?
17:45 Tom_itx uh huh
17:45 katsmeow-afk good deal
17:47 katsmeow-afk heh, your PCM12SMTR is listed same page for .85 each
17:47 Tom_itx .68
17:48 katsmeow-afk i wonder why everyone has the GTLP8T306MTC priced 5x more than the GTL2003PW ,, or do i care?
17:52 Tom_itx let's just not tell them
17:59 tsmeow-afk pon
17:59 KongfuPanda hello robotics people !
18:34 katsmeow-afk Newark has 1N944B for $7.30 each, #1 ebay seller has them for $30 each, and #2 ebay seller has them for $83 each
18:49 katsmeow-afk wow, 64kx4 45ns cmos static ram LH52252AD-45 is a watt per chip!
18:50 katsmeow-afk 20 megabytes of those would dissipate 640 watts!!
19:01 Triffid_Hunter katsmeow-afk: yeah sram is far less efficient than dram, but it's soo much easier to interface!
19:05 katsmeow-afk how about flash ram, here's some that 2x as big as the entire computer that access it's sound files and outputs sterio sound !! : http://elm-chan.org/works/sd8p/8pin.jpeg
19:06 katsmeow-afk course, it is 4gbytes of flash
19:08 katsmeow-afk hmm, the package that UPS claims they left on my porch yesterday ,, they now claim they left at the front door today
19:08 katsmeow-afk going to go look
19:23 katsmeow-afk nope, they were up at the road, outside th egate, wher the dogs could pee on them
19:39 katsmeow-afk what nerve, puts in a flyer begging for 5 stars, but gyped me 25% of the chips from the order
19:39 Tom_itx tell em
19:40 katsmeow-afk did
19:40 Tom_itx kat,what did i do wrong?
19:41 Triffid_Hunter katsmeow-afk: tell 'em they can have 75% of 5 stars since you only got 75% of your order
19:41 Tom_itx installed php and moved my webpages over but i try to open the main page and it tries to save it as a file instead
19:43 katsmeow-afk installed where moved where?
19:43 katsmeow-afk open with what?
19:44 Tom_itx ff
19:44 Tom_itx another server machine rue is helping me set up
19:44 Tom_itx but i was doing the web stuff myself
19:44 katsmeow-afk ahh, tell ff to open everything as html
19:44 Tom_itx i set up the directories right
19:44 Tom_itx the original works fine
19:44 Tom_itx i don't have something installed or something
19:44 katsmeow-afk or, to be safer, look at the associations in ff, add php if you need to
19:45 Tom_itx i'm not worried about the machine, this is a test only
19:45 katsmeow-afk the original where?
19:45 Tom_itx my pages you view
19:45 katsmeow-afk url
19:45 Tom_itx urnot
19:45 Tom_itx oh
19:46 tsmeow-afk opens ff in prep for an
19:46 Tom_itx http://tom-itx.dyndns.org:81/~webpage/
19:46 Tom_itx the other one is local
19:46 katsmeow-afk ok, that one works
19:46 Tom_itx i know
19:46 tsmeow-afk checks somet
19:47 Tom_itx i need to enable something or install something i think
19:47 katsmeow-afk nix?
19:48 Tom_itx huh?
19:48 katsmeow-afk the local server is winders or nix?
19:48 Tom_itx linux 6.0.4
19:49 Tom_itx it's local until rue can help me make it now
19:49 katsmeow-afk if nix, it's prolly a permission thing and the server is sending a.php and ff treats it like a binary file
19:49 Tom_itx not
19:49 Tom_itx i think i got them right but i'll check
19:49 Tom_itx what should it be?
19:49 Tom_itx i don't remember what i set them to
19:49 Tom_itx 663 maybe??
19:49 Tom_itx i forget
19:49 katsmeow-afk the php bin files and includes need to be executeable from apache
19:49 katsmeow-afk 774, i think
19:50 Tom_itx ahh
19:50 Tom_itx ok
19:50 Tom_itx lemme fire things up here and i'll look
19:50 Tom_itx i'm not entirely sure i have things installed quite right yet
19:50 Tom_itx we were working on a couple things at once
19:50 katsmeow-afk http://www.tuxfiles.org/linuxhelp/filepermissions.html
19:51 katsmeow-afk 755
19:51 katsmeow-afk yo may not want the world to have read and execute permissions
19:51 Tom_itx naw
19:51 katsmeow-afk just local apache
19:52 katsmeow-afk i dunno nix, i just run my webpages on a nix shared hosting
19:52 katsmeow-afk and php works fine up there
19:53 Tom_itx brb
20:06 katsmeow-afk two items not as described so far
20:13 Tom_itx ?
20:13 Tom_itx oh
20:13 Tom_itx your order?
20:13 katsmeow-afk yeas
20:17 katsmeow-afk i wonder if he added the unknown chip's number x the qty, and averaged it, to get a "part number" to advertise
20:24 Tom_itx :/
20:29 dunz0r This is an interesting presentation http://youtu.be/8CXReb7f0Eo
20:29 dunz0r Gave me some really good ideas for the "long-term build" robot
20:34 katsmeow i hate this place
20:34 katsmeow the place irl
20:34 Tom_itx how do i chmod this directory and everything below it?
20:37 Triffid_Hunter Tom_itx: chmod -R
20:37 Triffid_Hunter Tom_itx: careful of execute bits though, you can't cd into a directory that's -x
20:37 Tom_itx 775 ok?
20:37 Tom_itx err 755
20:38 Triffid_Hunter Tom_itx: yeah 755 is fine for dirs, don't necessarily want it on files though
20:38 Triffid_Hunter Tom_itx: to separate, use chmod -R u+rw,go+r path/ so it doesn't touch execute
20:38 Triffid_Hunter Tom_itx: alternatively, use find path/ -type f -execdir chmod 644 '{}' \;; find path/ -type d -execdir chmod 755 '{}' \;
20:39 katsmeow is that linux-speak for "format c:" ?
20:39 Triffid_Hunter Tom_itx: actually scratch that, apparently chmod will accept a+X (instead of lower-case x) to automagically choose the appropriate bit
20:39 Triffid_Hunter katsmeow: no this is permissions. mkfs.<filesystem> is the equivalent of format :P
20:40 katsmeow <whew>
20:43 Triffid_Hunter find path -type f finds all the files. -execdir command '{}' \; runs the command on the found files, replacing '{}' with the filename. find path -type d finds all the directories
21:07 katsmeow isn't it cute that when anyone can buy plugin modules at 900Mhz+ for projects, that humans once considered anything over the am broadcast band (topped out at 1.6Mhz) as "shortwave radio" ?
21:10 katsmeow more humans now own/operate bluetooth and wifi at 2.4Ghz now than all of everyone ever alive used CB radio at 27Mhz
21:33 katsmeow One gram of plant material (e.g., stems and leaves), which is largely carbohydrate, yields about 4.25 kcal of energy when burned (or respired).
21:40 rue_house katsmeow, "format c:" = "mkfs.ext3 /dev/hda1"
21:41 katsmeow "i don't do dat"
21:43 katsmeow i have a mostly clay hilltop, some 70ft above the water table (periodic wet-weatehr stream at the bottom of hill), no money for fertiliser, tractors, tillers, or lots of energy to pump the mostly non-existant water (in dry weatehr),, so what can i grow there?
21:49 katsmeow "MnVAP sells biomass fuel pellets in ... in 2000 lb. tote bags" <<== gotta use both hands with those tote bags
21:51 katsmeow "One bag of pellet fuel equals 2.3 gallons of oil or 3.5 gallons of LP gas." they mean alfalfa grass pellets
21:51 katsmeow i dunno if they mean those 2000lb bags
21:51 rue_house hahhaha
21:51 rue_house 2000lb tote bag eh?
21:52 katsmeow http://www.mnvap.com/biomass_fuel.htm
21:52 rue_house "excuse me, there seems to be a problem with this shopping cart, I put in one of the 2000lb tote bags of fuel pellets, and it just collapsed..."
21:54 katsmeow their webpage talks of electricity at 7 cents/kwh, and i don't think i ever saw power that cheap
21:56 theBear hehe, 2000lb tote bag... "excuse me, there seems to be a problem with my shoulder, I put one of these 2000lb tote bags on it, and it just collapsed !"
21:59 rue_house :)
21:59 rue_house theBear, mmm I wanted to play with that awesome schematic you found
22:00 rue_house it dosn't show the +12, -12, -5V supplies needed for the 41256
22:01 katsmeow "the research findings indicate that alfalfa may play a substancial role in stabilising energy use on farms as the energy efficency and nitrogen fixation potential of the species becomes better known", he says. "there are about 750 species of hummingbird found in the western hemisphere." <<== burning hummingbirds now?! because they are self-fanning or something??
22:01 rue_house heh
22:02 rue_house http://elm-chan.org/works/srp/srp.png
22:02 rue_house kat, how does that adc work now...
22:02 katsmeow we useto call alfalfa pellets "rabbit food" , not "fuel"
22:02 katsmeow it's a pwm sar convertor
22:02 theBear 41256 needs -12 ?
22:02 rue_house I think it needs the full gammit
22:03 katsmeow you can use any ram chip
22:03 rue_house seperate input and output
22:03 theBear what a crazy old chip :)
22:03 rue_house theBear, you didn't think the muxed address bus was the only challange!
22:03 katsmeow it's oeprated as fifo, yeas
22:03 theBear kats makes a good point tho, and well, i'd only be likely to use what i can find around the house
22:03 theBear pfft, -12 isn't a challenge
22:03 rue_house no tat the current it needs
22:04 rue_house ah
22:04 katsmeow as a fifo, read out the data before you write it, you can use one-data-port chips fine
22:04 rue_house so, the clock makes the lm311 operate as an oscillator
22:05 katsmeow the osc freq determines the rate the memory is run thru, which is the delay time
22:05 theBear kinda an oscillator and kinda a delta-sigma-machine
22:05 theBear that's the part of the trick i like, damn i wish i'd thought of/found this trick 10 years ago
22:05 rue_house something still dosn't add up in my head tho
22:05 katsmeow it's really low resolution, you can do much better now, i becha
22:06 rue_house is it tho, whats its time delta from min to max voltage
22:06 theBear katsmeow, just the concept of 'common' chips to do delta-sigma ... grab a fast flipflop and a 'real' ram/digital side....
22:06 rue_house hmmm
22:06 katsmeow it's so low res, just looking at it in memory, it has a lowpass before the adc and a low pass after the dac
22:06 rue_house wel you could stick a counter on there too
22:06 rue_house yes, to 8Khz
22:07 katsmeow on that schematic, there's two counters
22:07 theBear it's designed for 'rear speakers' .... it's not supposed to be full range or anything like that, i just like the concept
22:07 theBear without writing down tables, it looks like the two counters are alternating between read and write cycles, therefore the fifo effect
22:07 rue_house katsmeow, row and column
22:07 tsmeow arrrgggg
22:08 theBear ahh rue, genius
22:08 katsmeow rue, 32k: 8 bits low and 7 bits high
22:08 theBear it's only wired for 7 +7 tho
22:08 katsmeow note bit 15 is grounded, iirc
22:08 rue_house no its 8
22:08 theBear oh no, 8 sorrry
22:08 rue_house 0-7 = 8
22:08 rue_house the 9th address line is grounded
22:08 katsmeow 8 low, 7 high
22:08 theBear silly "zero is a number"
22:09 theBear but if that's 7 high, what stops it counting the 8th high ?
22:09 theBear oh, 64k
22:09 rue_house the ram chip will just ignore and roll over
22:09 rue_house which is odd, its a 256k chip
22:09 theBear but you need a smooth rollover
22:09 theBear what ?
22:09 theBear oh jeez
22:09 katsmeow it's used as 32k tho
22:09 theBear i see
22:09 rue_house yea, 0x80 = 0x00
22:09 theBear and labelled at 64k <grin>
22:09 katsmeow there's only 15 active addy lines
22:10 rue_house and its a256k chip
22:10 rue_house 41 (256k)
22:10 theBear hehe
22:10 katsmeow <shrug>
22:10 e_house sh
22:10 rue_house who has a 41256 datasheet?
22:10 e_house looks at
22:10 theBear makes me tempted to try a 'lo-fi' 'real' digital delay
22:10 eBear looks at alldatasheet
22:11 rue_house eeeeeeeeeeeeeeek locate 41256 came up empty
22:11 katsmeow anyhoo, use a modern avr which has proper adc on it, stuff the data into ram using one of the 16bit counters set to roll over, using a circuit that steals 1/2 the write cycle to read before write
22:12 theBear here's one
22:12 theBear http://www.alldatasheet.com/datasheet-pdf/pdf/113615/OKI/MSM41256A.html
22:12 rue_house A8....
22:13 rue_house is used to select which bit of the internal nibble your working with...
22:13 katsmeow i dunno why you wanna do it the way someone did it 20 yrs ao when he was a newbie
22:13 rue_house :/
22:13 theBear i don't wanna do that, but we spent half a hour dissasembling the circuit, may as well finish it
22:14 rue_house you have 4ms max delay, or your data is gone
22:14 theBear and i don't think this guy was a noobie that long ago <grin>
22:14 theBear rue_house, he switches clock speeds, not pretty, but it works
22:14 omilu
22:14 theBear you can't "miss" the data, unless you mean with the avr
22:14 rue_house omilu, could you say nothing louder?
22:14 rue_house theBear, no, after 4ms, the cell has decayed
22:15 katsmeow hence, use static rams
22:15 theBear oh,.... maybe he was just lucky /
22:15 theBear or maybe he used a much slower version, i think that was a 10ms chip
22:16 katsmeow he wasn't lucky, since he cycled constantly thru all lower 8 address lines, all the cells got refreshed constantly
22:16 rue_house I dont think I understood the refresh cycle right
22:16 rue_house ah, thats what I thought I didn't understand right
22:16 theBear interesting.. i didn't knowthat was enough to refresh
22:16 omilu we run 2 watt radios in semi fixed deployments on 7.5v alkaline batteries
22:16 theBear hehe good for you
22:16 omilu we use 4 batteries 2 in series then 2 in parrallel
22:17 rue_house omilu, I have a red S10 truck
22:17 katsmeow all the olde puters like the vic20 , C64, zx80, etc, used constant video reads on the low 8bits of address to refresh the drams
22:17 omilu for 15V output
22:17 omilu the thing dies when the batteries reach a voltage of 10.5V
22:17 rue_house omilu, my truck uses 6 2V cells wired in series
22:18 omilu but each battery still has a ton of juice
22:18 rue_house omilu, what kind of battery are they?
22:18 tsmeow wonders if omilu is trying to teach us, bragging, or has a question in
22:19 omilu so than we restack the batteries instead of 2 in series 2 in parrallel
22:19 omilu we got to 4 in series
22:19 rue_house omilu, please resond with lithium-ion, nicad, NiMh, alkaline, or other
22:19 omilu alkaline
22:19 rue_house ah, one time
22:19 katsmeow he is using alkline
22:19 rue_house an alkaline is dead at 1V
22:19 rue_house technically
22:19 theBear hmm... alkaline don't really like 2/3 voltage do they ?
22:19 omilu right you can run them down to basically nothing
22:20 theBear erm, these single use alkalines ?
22:20 rue_house no, the resistance of them goes WAY up at less than 1V
22:20 omilu but since our radio needs at 10 - 17vdc
22:20 katsmeow yeas, you kinda need 12 in series and a low-v-dropout switcher downconvertor to 12v
22:20 omilu anyway that was my question, we were hooking up this complex relay system
22:21 rue_house no
22:21 rue_house use a switcher like kat said
22:21 katsmeow you can get switching up/down convertors too, and keep the 2-2 configuration
22:21 rue_house omilu, what voltage do you want to take the cells down to?
22:21 katsmeow the down-convertor is most efficient
22:21 rue_house agreed
22:21 omilu when the batteries get down to 10V the relays kick in and eessentially reconfigure the batteries for us automatically
22:21 omilu retarded??
22:22 rue_house use ~24V in battieres and by the time the swticher is down to 1:1 the batteries have less than .5V left
22:22 katsmeow no, but lowtech and has failure modes
22:22 rue_house omilu, not as good as a switcher, cause of the power the relays take
22:22 omilu right, also thinking about running the 7.5 all in parrellel
22:22 rue_house buck converters can be as good at 99% efficient
22:22 omilu then using a boost converter to get the correct output voltage
22:22 rue_house no
22:23 rue_house run high battery voltage and buck down
22:23 katsmeow you lose power in boost convertors, avoid them if you can
22:23 rue_house buck converters have a higher input impedence, which your battieres will need when they are below 1V
22:23 omilu yeah but stacking them in series, essentially doubles the load on each battery
22:24 katsmeow no
22:24 rue_house think of a alkaline down to 1V as a 1V battery with a 10 ohm resistor in series
22:24 katsmeow a properly set up switcher "thinks" in watts over time, not volts and current separately
22:24 omilu in transmit the radio draws about 2 amps
22:25 omilu 4 batteries in series, each one supplying 2 amp load, alkaline capacity heavily dependant on load current
22:25 rue_house buck supplies are easy to make and can easily handle a lot of power
22:25 rue_house no
22:26 rue_house with a buck supply 10V out at 2A only needs 1A of 20V in
22:26 rue_house constant power
22:26 katsmeow properly set up, rue's 24v no-load battery bank will need to deliver only 1/2 the current TO the switcher as the switcher is delivering to the radio, even tho it's the same WATTS in as out,, and the batterys will thank you for it
22:26 omilu really????
22:26 katsmeow seriously
22:26 omilu i will look into it
22:26 rue_house where as a boost outputting 10V at 2A will requre 4A if its input is 5V
22:26 rue_house calculate the power
22:26 theBear honestly, they might not thank you literally, apart from that, seriously
22:26 rue_house 10V 2A = 20W
22:26 rue_house 5V 20W = 4A
22:27 rue_house 20V 20W = 1A
22:27 rue_house 40V 20W = 0.5A
22:27 omilu i han't looked to cloesely at bucks, only linears
22:27 omilu which knock the voltage down by turning into heat
22:27 theBear linear + batteries = not cool
22:27 theBear hehe, literally too :)
22:27 Triffid_Hunter omilu: yeah use a switcher, they're awesome except for noise
22:27 rue_house the REASON you want to LOWER the current on the dead batteries is because they have an internal resistor that gets larger as the battery dies
22:27 omilu thanks guys, I'm inspired
22:28 rue_house omilu,
22:28 rue_house look at a datasheet for
22:28 rue_house the
22:28 rue_house uc3842
22:28 rue_house I think
22:28 rue_house just as a switching converter example
22:28 rue_house there are a lot of much easier chips to use
22:28 Triffid_Hunter and yeah, with batteries buck rather than boost if you can, switchers exhibit negative differential resistance on the input side, they draw /more/ current as the voltage drops, to maintain the same power. that's bad news for low batteries
22:29 Triffid_Hunter buck does it too I suppose, not sure which is less stressful
22:29 rue_house the buck will be less current tho
22:29 omilu will look at the uc3842 thanks ruehouse
22:30 omilu the other plan we have for minimizing battery consumption
22:30 Triffid_Hunter rue_house: sure, but not necessarily less current _per battery_
22:30 rue_house dude, their in series
22:30 omilu did i mention these things are $25 a piece
22:30 rue_house but yea, if youhave the same number of batteries I usppose its the same per cell
22:31 Triffid_Hunter rue_bed: bear with me for a sec.. imagine 4x 6v batteries, in series we have 24v. assume a 24w load so that's 1A in the series arrangement. in parallel, we need 4A but that's still 1A per battery
22:31 rue_house theBear, aha! the 41256 is 5V only
22:31 rue_house Triffid_Hunter, agreed
22:31 omilu is to use this spare laptop battery from tekeon
22:31 rue_house buck is still easier to make
22:31 rue_house you can really screw up the inductor and be ok
22:32 omilu its liion with built in charge circuitry, and selectable output voltage
22:32 omilu basically maximum size liion, not to be considered a hazardous material
22:32 rue_house omilu, carefull of the miniumum cell voltage
22:32 theBear selectable output voltage ?
22:32 rue_house li-ions can explode if undercharged ""
22:33 rue_house or overcharged
22:33 omilu yeah you set a dip switch for the output anywher from 5 to 19V
22:33 omilu anyway the plan is a flexible solar panel, plugged directly into this tekkeon
22:33 Triffid_Hunter omilu: lm2596 comes to mind as a decent buck switcher
22:34 rue_house yes!
22:34 rue_house I couldn't think of the part numbers for those
22:34 omilu which goes to a double polt single throw? relay
22:34 rue_house thanks
22:34 Triffid_Hunter yw
22:34 omilu roger lm2596 will check it out thanks triffid
22:34 rue_house hey, I didn't say tl494 :)
22:34 rue_house or KA7500 :)
22:35 omilu the laptop batterie ain't got enough capacity and will die often, then the micro switches the relay so the radio is running off the alkalines
22:35 rue_house according to the datasheet lm317 can do switching too :)
22:35 rue_house omilu, the relays have coils that just eat power
22:36 omilu when the liion gets enough charge the micro switches the relay back so the radio is running off the liion most of the time and only use the alkalines as a last resort
22:36 rue_house you can have them either eat power when your batteries are not dead, or when they are
22:36 omilu the relays are latchers, so you just got pulse current through them then they latch
22:36 rue_house ah
22:37 rue_house amazed you found a latcher that can do 2A
22:37 omilu anybody got better ideas for saving batteries, mucho expensive
22:37 theBear get a smaller radio ?
22:37 rue_house fix the circuit they operate
22:38 rue_house 2A at 10V, I'm sure its not a 20W radio
22:38 omilu 2Watt radio
22:38 omilu actually repeater
22:38 rue_house so where is the other 8W going?
22:38 Triffid_Hunter rue_house: (re lm317) yeah I know, I've come across that datasheet myself, don't think it's terribly good at it though!
22:38 rue_house Triffid_Hunter, iirc I tried it a few times, dosn't work worth a damn
22:39 theBear hmm.... i smell like dead ants this week
22:39 rue_house what does a dead ant smell like?
22:39 theBear i dunno, never squashed a ant ?
22:39 Triffid_Hunter rue_house: formic acid, they use it as an alarm scent
22:39 rue_house not a smelly one
22:39 theBear there ya go, formic acid
22:39 rue_house bit late if they are already squished
22:40 rue_house formic is what they use on bricks isn't it?
22:40 Triffid_Hunter rue_house: may have to squash a few of them if you want to know what it smells like.. very acrid, sorta like HCl without the hair-curling sensation and a bit more organic
22:40 Tom_itx collecting supper?
22:40 theBear nah, that's umm, i wanna say hydrocloric
22:41 Triffid_Hunter sorta like what you'd expect it to smell like if you mixed heaps of mushrooms with HCl
22:43 omilu anybody ever try growing mushrooms
22:43 omilu suprisingly easy
22:45 Triffid_Hunter omilu: no, planning to though.. lots of psilocybin cubensis in this area :D
22:47 theBear mmm... i been thinking like triffid on this subject
22:47 rue_house hmm I wanto build that adc
22:47 rue_house but its output is relative
22:48 theBear rue_house, for experimenting, i suppose a dual flipflop and a couple opamps would be enough
22:48 rue_house I have lm311 and 7474
22:48 rue_house matter a fact, I had to empty a tube of 7474 OUT of the drawr to fit more in
22:48 theBear hehe
22:49 rue_house :) maybe I should do it with a 555 tho, just to be cheaky
22:49 rue_house oh , no you need a D flipflop, not RS
22:49 rue_house tiny13 :)
22:50 rue_house er, tiny10 I mean
22:50 rue_house IT HAS TO BE USEFULL FOR SOEMTHING!
22:51 rue_house why a 12V supply on the comparitor I wonder
22:52 theBear 'cos it's audio levels and 12 or 15v just makes sense
22:52 theBear yer only doing 1 bit, you don't care about headroom :)
22:52 rue_house but the return path is only good to 5V so its range is still only 0-5
22:53 theBear yeah, probly the other half of it was in 'analog' land
22:54 rue_house I also find it odd that the input level is scaled to 5V and not ground
22:54 theBear single supply ? i haven't looked at the schem for 20 mins btw
22:55 rue_house they mix the inputs, lowpass 8Khz, and then their scale for that output goes from the lowpass to +5
22:55 rue_house no thats screwed up, it should be to a 2.5V ref
22:56 rue_house no cause its AC coupled
22:59 rue_house http://www.hitequest.com/Kiss/DeltaSigma.htm
22:59 rue_house tahts what missing
22:59 rue_house they dont reset at a static rate
23:12 theBear erm, that link don't seem to work
23:24 rue_shop these power outages are being annoying
23:27 rue_shop !time
23:27 tobbor My watch says its 21:20 Tue Feb 28 2012
23:29 rue_shop !seen cow jumping over moon
23:29 tobbor I have never seen cow jumping over moon
23:32 Tom_itx !seen it rain cats and dogs
23:32 tobbor I have never seen it rain cats and dogs
23:34 rue_shop should I do god again, just for entertainment?
23:34 rue_shop so I made a DSL detector for phone lines
23:45 rue_shop wow
23:45 rue_shop printed out the overload board onto glass
23:46 rue_shop I cant see a single improvement
23:50 rue_shop ok, beditm
23:50 rue_shop e
23:50 rue_shop itme / time
23:56 rue_house so if you add a diode in parallel with the 39k resistor, it would give you an absolute reading
23:57 rue_house er no
23:57 rue_house in series... no
23:57 rue_house hmm