#garfield | Logs for 2016-08-27

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[00:00:03] <rue_shop3> no, here were lucky its free
[00:01:00] <rue_shop3> ok I used the new adapter baords to make 4 little fets
[00:01:36] <rue_shop3> they come out about the size of a to-126
[00:01:36] <katsmeow> free? you sell them to a recycle for free?
[00:02:04] <rue_shop3> we are allowed to drop them off at no cost
[00:02:55] <katsmeow> umm, places here, if you drop them off, they give you free money
[00:03:02] <rue_shop3> if I'm gonna take over the world, I'm gonna need to write more avr code
[00:03:25] <rue_shop3> yea, if you have a truckload of big ones you can get a few bucks
[00:03:49] <rue_shop3> iirc scrap steel is $10/tonne
[00:04:35] <katsmeow> markup for making new steel from scrap is 100x , you should get into that
[00:04:53] <rue_shop3> too hot for me
[00:06:11] <rue_shop3> could I give you a browsing project?
[00:06:30] <rue_shop3> I need a good two-ding boat bell wav/mp3/whatever
[00:06:46] <rue_shop3> couldn't find one
[00:08:23] <katsmeow> really, searching for bell sounds on youtube?
[00:09:08] <katsmeow> https://duckduckgo.com/?q=bell.wav&t=ffsb&ia=web
[00:12:18] <rue_shop3> no I need a link to a real file that can be downloaded
[00:12:38] <rue_shop3> most of those are sites that dont have the files they say they have or the sounds are paid or no good
[00:12:48] <katsmeow> i cannot guess which one you will find acceptable
[00:13:11] <rue_shop3> just a nice *ding ding* from a boat bell
[00:13:38] <katsmeow> then check out old boat videos?
[00:14:00] <katsmeow> i have no sound on this puter, so..............
[00:16:34] <rue_shop3> hey ok, I thought you might be able
[00:17:04] <rue_shop3> when I find one, I have to convert it to 8Khz mono and try to fit it on an avr
[00:17:28] <rue_shop3> then hook it up to a 20W amp for the 30W PA horn
[00:17:59] <rue_shop3> and make a temp stand for the beam detector at the driveway
[00:18:14] <rue_shop3> make the beam sensor, pull all the wire thru the pipes,
[00:19:48] <katsmeow> yanno, in the olden daze, they used a rubber tube across the drive, a pneumatic cylinder to strike an actual bell
[00:20:17] <rue_shop3> I have one, I want something that dosn't have to be stepped on
[00:20:18] <katsmeow> or, an air bladder to strike th bell
[00:20:41] <katsmeow> you wanna detct the mowerbot escaping?
[00:20:57] <rue_shop3> or people walking in
[00:30:58] <katsmeow> hmm, lotsa small boat videos, no bells
[01:37:10] <rue_shop3> kat, analog 8:1 40__
[01:37:16] <rue_shop3> not 53
[01:37:19] <rue_shop3> 81?
[01:37:24] <rue_shop3> or was that xor
[01:38:12] <katsmeow> "analog" it?
[01:39:20] <rue_shop3> 51?
[01:39:30] <rue_shop3> 4051
[01:39:42] <katsmeow> oh, 8051
[01:39:48] <katsmeow> err, 4051
[01:40:23] <katsmeow> steam loco history video, in 6 parts, BBC
[01:41:43] <rue_shop3> I'm just wondering if a set of 4051 -> 2 microcontroller adc channels, would be better than a slave 10 channel adc microcontroller
[01:42:01] <rue_shop3> I kinda suspect the speed difference dosn't matter
[01:42:20] <rue_shop3> I think I'm targeting 300hz sample / channel, or less
[01:42:29] <rue_shop3> anyhting over 100hz is prolly fine
[01:45:51] <katsmeow> well, if you put a opamp tween the 4051s and the avr, you may get more accurate results, just because of the lower driving impedance of the opamp
[01:46:14] <rue_shop3> the avrs are pretty high impenence
[01:46:33] <katsmeow> k
[01:49:30] <rue_shop3> up to 15ksps
[01:49:32] <rue_shop3> so
[01:49:47] <rue_shop3> thats still ~1ksps @ 16 channels
[01:49:56] <rue_shop3> and I'm ok with 300Hz
[01:50:19] <rue_shop3> sounds like I could sample 50 channels and still make time
[01:50:33] <rue_shop3> nearest power of 2 being, 32
[01:50:49] <rue_shop3> would give almost 500Hz samples
[01:51:11] <katsmeow> remember after the adc for each channel, you need to send the data out to somewhere, SERIALLY
[01:51:21] <rue_shop3> so I CAN use 2 4051 instead of an external adc chip
[01:51:30] <rue_shop3> no, its a loop controller
[01:51:40] <rue_shop3> I need to do math and output pwm info
[01:51:49] <rue_shop3> to a chip that kinda does the pwm for me
[01:52:11] <rue_shop3> well, this screws over my tiny26 cheapo adc idea
[01:52:16] <katsmeow> i'd still use the externall avr as a contoller for the 4051, you need address lines into the 4051
[01:52:16] <rue_shop3> maybe
[01:52:23] <katsmeow> you'll need 4 addy lines
[01:52:27] <rue_shop3> I ahve enough spare pins
[01:52:38] <katsmeow> pins not the issue, time is
[01:52:40] <rue_shop3> I can parallel the address lines, and use 2 analog channels on the micro
[01:52:59] <rue_shop3> 8:1(x2) -> 2:1
[01:53:03] <katsmeow> while the micro is adc'ing, isn't it unable to compute?
[01:53:19] <rue_shop3> no, you start it and get an interrupt when its finished
[01:53:37] <rue_shop3> I use the interrupt to store the value in an array and set flags to say new values are available
[01:53:56] <rue_shop3> which allows the computations to by asynchronous
[01:54:00] <rue_shop3> to be
[01:54:16] <rue_shop3> for $13 I can get 100pcs 4051
[01:54:29] <rue_shop3> http://www.aliexpress.com/item/100PCS-CD4051BE-DIP16-CD4051-DIP-new-and-original-IC-free-shipping/32544321959.html
[01:54:40] <rue_shop3> cause I want dip
[01:55:09] <rue_shop3> tho two 4051 are more board space than one tiny26
[01:56:02] <katsmeow> you are up awefully late, whassup?
[01:56:07] <rue_shop3> which is about $20 to me
[01:56:14] <rue_shop3> its friday
[01:56:36] <katsmeow> kids tuhmorruh?
[01:56:43] <rue_shop3> I dont think so
[01:56:47] <rue_shop3> nobody called
[01:56:50] <katsmeow> tuhmaruh
[01:56:58] <katsmeow> k
[01:57:27] <rue_shop3> I have 3 4051 in stock
[01:57:33] * katsmeow resumes slurping her ramen-mackrel-basil-hotsauce
[01:57:35] <rue_shop3> 100pcs would prolyl be of use
[01:58:06] <katsmeow> i have 330
[01:58:14] <rue_shop3> smt or dip
[01:58:50] <katsmeow> HC, so prolly smd
[01:58:59] <rue_shop3> yar, I want dip
[01:59:50] <katsmeow> grabbed 650 hc4053 for $12, they are smd
[02:00:28] <rue_shop3> I'll regret the dip one day, but for now its what I'm after
[02:01:18] * katsmeow would do something stupid like put the dips side by side and the avr other side of bd under them
[02:01:41] <rue_shop3> well, I figure if I want I can always roll over the pins
[02:01:52] <katsmeow> you *can* smd dips, yanno, done that 40 yrs ago, got into trouble
[02:02:20] <rue_shop3> if anything I'd regret not being able to make the circuits smaller
[02:02:29] <rue_shop3> I havn't etched a board in a long time
[02:02:47] <rue_shop3> this motor driver thing is getting me close
[02:03:14] <rue_shop3> was trying to layout a double sided baord with a half bridge on each side, resulting in a dip8 that was a full H bridge
[02:03:25] <rue_shop3> +, _, g1, g2, g3, g4, out
[02:03:31] <rue_shop3> and out...
[02:04:36] <katsmeow> CD family is old, prolly all the CD4051 are dips
[02:05:10] <rue_shop3> HEF is pricier
[02:05:26] <katsmeow> hmm?
[02:06:15] <rue_shop3> 74HC is even more expensive
[02:06:19] <rue_shop3> $45 for 100pcs
[02:06:34] <rue_shop3> $32
[02:06:45] <rue_shop3> $20
[02:07:22] <katsmeow> 50PCS CD4051BE CD4051 DIP-16 IC GOOD QUALITY
[02:07:27] <rue_shop3> 16.38
[02:07:52] <rue_shop3> 16.12
[02:10:08] <rue_shop3> do you think 74HC will outdo CD ?
[02:10:46] <katsmeow> 100 PCS HCF4051M SOP HCF4051 CD4051 SMD DEMULTIPLEXERS
[02:11:04] <katsmeow> HC should be faster and have better static protection
[02:11:07] <rue_shop3> no kat, dip
[02:11:22] * katsmeow curtseys
[02:12:49] <rue_shop3> comparing...
[02:13:31] <katsmeow> can't you scratch some solder pads into some copperclad, using the cnc mill?
[02:14:03] <rue_shop3> 74HC : 200R
[02:14:58] <rue_shop3> CD: 270R
[02:15:08] <katsmeow> hc should be 30
[02:15:47] <katsmeow> oh, you should al;so consider the 40xx is all above ground
[02:16:36] <katsmeow> there's no negative signal to it, and if you set it on -5/gnd/+5 , your ttl control must be in the gnd/-5 range
[02:17:12] <rue_shop3> they dont really say much about switching times
[02:17:38] <rue_shop3> I'm using the 0V-5V ratings
[02:18:27] <katsmeow> oh, fets are high resistance at 5v
[02:19:16] <katsmeow> check out the 74LVX8051
[02:20:08] <katsmeow> the PI5L200W is only 6 ohms
[02:20:17] <rue_shop3> hmm not availabe in dip
[02:21:01] <katsmeow> the IDTQ531255I(?) is 5 ohm
[02:21:04] <rue_shop3> your knowledge of strange part numbers is amazing
[02:21:17] * katsmeow dips
[02:22:12] <rue_shop3> your strange parts ARE awesome, but price and dip result in a cd4051, which looks sufficient for 7khz switch sampling?
[02:22:22] <katsmeow> ok
[02:22:31] <rue_shop3> .. or does it?
[02:22:55] <rue_shop3> on delay of 435ns
[02:22:59] <katsmeow> 100khz should be easy
[02:23:20] <katsmeow> the capacitances are the birtch tho
[02:23:34] <rue_shop3> hmm
[02:23:41] <rue_shop3> I'll get them, its $20
[02:24:48] <rue_shop3> if I ever need a really good chip, can I get those numbers from you again?
[02:25:15] <katsmeow> trying to not wear out the elecrons, but ok
[02:26:36] <katsmeow> the really high speed low ohm alanog switches might be found in your dsl routers and things pile
[02:26:57] <katsmeow> amalog
[02:27:06] <katsmeow> alanog
[02:27:24] * katsmeow pondes nog made with almonds
[02:29:31] <katsmeow> yanno too, factories that use all robots and no humans cannot be called "manufacturing" because the word means "making by hand" in the original Latin
[02:29:37] <katsmeow> need a new word
[02:32:28] <rue_shop3> well, I got a bit further on this 8 servo loop controller
[02:44:14] <rue_shop3> so I get 0.3 degrees resolution
[02:44:15] <katsmeow> can you move your lbow to that resolution?
[02:44:15] <rue_shop3> my welder sunburned my left arm
[02:44:15] <rue_shop3> 0.3 degrees is 1/1200 of a rotation
[02:44:15] <rue_shop3> my arm is, lets say 12"
[02:44:15] <rue_shop3> circ of 75"..
[02:44:15] <rue_shop3> 63 thou over 12"
[02:44:15] <katsmeow> right
[02:44:16] <rue_shop3> BUT, the servo might be +- 10 units
[02:44:16] <katsmeow> great resolution, but you better have the motion (inertia/momentum, mechanical slop) algos to deal with it
[02:44:16] <rue_shop3> so, within half an inch
[02:44:16] <rue_shop3> +-
[02:44:16] <katsmeow> well, +/- 1/2 inch is sloppy if you wann get a teacup off the shelf
[02:44:16] <rue_shop3> then again, the pneumatic servo was able to get to +- 2 units
[02:44:16] <katsmeow> and don't want the robot to have palsy , hunting for the right angle, while carrying your soda
[02:44:56] <katsmeow> tiny joke about all the muscle control diseases is all the softdrinks being flat by the time yu drink them
[02:45:40] <rue_shop3> :)
[02:47:38] <rue_shop3> I cant stay awake,
[02:47:43] <rue_shop3> but I'v not had supper yet
[02:47:44] <katsmeow> ok
[02:47:45] <rue_shop3> arg
[02:47:52] <katsmeow> i just finished breakfast
[02:50:26] <rue_shop3> the idea is to do over the wire force feedback,
[02:50:46] <rue_shop3> I wonder how I should phrase the current polarity
[02:51:09] <rue_shop3> maybe I'll dial it back to 9 bits and use the driving polarity as the clue... tho...
[02:51:40] <rue_shop3> and I need to work out current regulation on the opposite end
[02:51:50] <rue_shop3> but I'd like the ends to be generic
[02:51:51] <rue_shop3> hmm
[02:52:10] <rue_shop3> one will be positon control with current feedback and the other will be current control with position feedback
[03:03:37] * katsmeow goes afk to do things irl
[07:17:35] <katsmeow-afk> !!!!!!!!*********_____RUE YOU HAVE EMAIL ____*********!!!!!!
[11:24:02] <rue_shop3> I did I did
[11:24:16] <rue_shop3> kat and me both apparently like locomotives
[11:24:35] <rue_shop3> so
[11:25:05] <rue_shop3> to get 16 channels on a microcontroller, it takes less space to use another microcontroller than to use an analog mux
[11:25:41] <rue_shop3> AND because its doing its own sampling, you get a higher sample thruput
[11:26:14] <rue_shop3> I suppose the mux is worth it if you only want to add 7 channels
[11:26:23] <rue_shop3> hmm
[11:27:05] <rue_shop3> I wonder if a tiny13 costs more or less than a 15ksps 2 channel, 10 bit adc
[13:45:42] <katsmeow-afk> rue, they are Brit engines
[21:03:14] * Tom_itx pokes a finger in rue_shop2's right ear and watches it come out rue_shop3's left ear
[21:03:28] * Tom_itx hmmmm....
[21:35:14] <rue_shop3> well I got some welding done on the boiler and the pipe bender
[21:35:58] <rue_shop3> I told myself I'd hvae the pipe bender working this summer, fall is kinda here so I need to stay busy on it
[21:57:05] <rue_shop3> 00000000000000000000000000000000000000000000..
[22:01:30] <rue_shop3> ps
[22:28:54] * katsmeow sings a chorus of meows
[22:31:38] <katsmeow> rue, The Flying Scotsman is a classic case of confusing the issue, there were 3 versions of that engine
[22:33:06] <katsmeow> the original was best for it's day, except it had narrower steam pipes
[22:33:31] <katsmeow> the year after, faster and more powerful engines came out
[22:34:38] <katsmeow> during the multi-$million rebuild, the superheater was changed, the stack draft was doubled, the pipe area was doubled, and the driving piston dia was increased
[22:35:04] <katsmeow> and after a few yrs runing on the main rails at 75mph, it needed another rebuild
[22:44:36] <katsmeow> the first rebuild was somewhat undone during the 2nd rebuild, so it ran slower again
[23:05:00] <rue_shop3> hmm
[23:05:12] <rue_shop3> a candle that burns twice as bright
[23:22:33] <katsmeow> i am so about to faceplant, i need to go lay down for my own physical safety
[23:23:00] <rue_shop3> did you know blisters generate gas
[23:23:07] <rue_shop3> (air or the like)
[23:23:20] <rue_shop3> I been trying to cover a torn off blister with glues
[23:36:02] <Tom_itx> rip the skin off and tough it out
[23:40:49] <rue_shop3> it did, I'm tryin to put a dust cover on