#garfield Logs

Aug 16 2020

01:28 AM polprog: morning
01:34 AM polprog: rue_mohr: the leds video played ok in twitter
01:34 AM polprog: in firefox
01:40 AM rue_shop1: ok
01:57 AM zhanx_workshop: ok printer is retuned and printing
01:59 AM rue_shop1: your up late too
02:02 AM zhanx_workshop: no i am reverse cycle due to the heat
02:15 AM rue_shop1: ooooh
02:15 AM rue_shop1: click
02:16 AM rue_shop1: if I make an lcd bar graph that has a 0.25v resolution for a bench power supply
02:17 AM rue_shop1: is that good enough?
02:17 AM rue_shop1: lcd, I could pair it with digits
02:17 AM rue_shop1: the current resolution would be 62.5mA
02:17 AM rue_shop1: hmm
02:18 AM rue_shop1: I dont think its any less resolution that I'd get from an analog meter
02:20 AM rue_shop1: 80 divisions over 7cm
02:20 AM rue_shop1: hmmm
03:17 AM polprog: sounds cool
03:17 AM polprog: i got some 22v10 gal
03:18 AM polprog: the guy didnt have LM75
03:18 AM polprog: but i got some LM335
03:18 AM polprog: some VCR scrap boards for the tv tuners
03:18 AM polprog: some +-1 overflow displays
03:19 AM polprog: some red leds and loads of simm ram
04:56 AM polprog: https://i.ibb.co/nc3XSFm/IMG-20200816-115143.jpg
07:05 AM polprog: rue_mohr: https://polprog.net/rozne1/ircjunk/various/555lol.jpg
07:06 AM polprog: i should try removing the reset wire, and pull up pin 6 directly, i could maybe also remove the resistor between 2 and 3
07:42 AM polprog: heh, ofc it works with reset floating ;)
08:44 AM polprog: heh, the RF modulator works :)
09:52 AM Tom_itx is now known as Tom_L
10:22 AM rue_bed2: hmm
10:24 AM rue_bed2: otorola is a pager or ?
10:24 AM polprog: yeah. a pager
10:24 AM polprog: i doubt there are active pager networks out here..
10:25 AM polprog: and i dont have any way to send pages to it either
10:25 AM polprog: it was small and cheap
10:42 AM polprog: rue_mohr: so the 555 works without the reset pin ;)
10:42 AM rue_bed2: I know
10:42 AM rue_bed2: pin 4 is a lie
10:42 AM rue_bed2: :)
10:42 AM polprog: ;)
12:03 PM ShopMoon: rue_bed2: Awake then?
01:36 PM polprog: i usually check time.gov to know that ')
01:36 PM polprog: ;)
01:40 PM aandrew: https://imgur.com/a/VRsQkxF
01:45 PM polprog: i should fix up my temp logger.. its got some noise
01:45 PM polprog: but it works good!
01:45 PM polprog: https://polprog.net/rozne1/ircjunk/t.svg
02:00 PM polprog: nice.. 3rd modulator/demodulator
02:00 PM polprog: i guess this makes it a TV mo-dem>
02:00 PM polprog: :P?
02:13 PM Tom_L: polprog, did you see that lightbulb hack?
02:14 PM polprog: which one?
02:15 PM Tom_L: https://www.youtube.com/watch?v=PUjaSYpyF6k
02:15 PM polprog: ah yeah
02:15 PM polprog: i have it aved
02:15 PM polprog: saved*
02:23 PM polprog: Tom_L: looks like some self resonant circuit.. but i cant tell which way the voltage will or should induce
06:07 PM KitchenMoon: Why would this loop forever and overflow the char?
06:08 PM KitchenMoon: int main() {
06:08 PM KitchenMoon: char x;
06:08 PM KitchenMoon:
06:08 PM KitchenMoon: for ( x=0; x < 128; x++ ) {
06:08 PM KitchenMoon:
06:08 PM KitchenMoon: putchar(x);
06:08 PM KitchenMoon: }
06:08 PM KitchenMoon:
06:08 PM KitchenMoon: return 0;
06:08 PM KitchenMoon: }
06:08 PM KitchenMoon: --
06:08 PM KitchenMoon: 5c1: 0f be 45 f7 movsbl -0x9(%ebp),%eax
06:08 PM KitchenMoon: 5c5: 83 ec 0c sub $0xc,%esp
06:08 PM KitchenMoon: 5c8: 50 push %eax
06:08 PM KitchenMoon: 5c9: e8 42 fe ff ff call 410 <putchar@plt>
06:08 PM KitchenMoon: 5ce: 83 c4 10 add $0x10,%esp
06:08 PM KitchenMoon: 5d1: 0f b6 45 f7 movzbl -0x9(%ebp),%eax
06:08 PM KitchenMoon: 5d5: 83 c0 01 add $0x1,%eax
06:08 PM KitchenMoon: 5d8: 88 45 f7 mov %al,-0x9(%ebp)
06:09 PM KitchenMoon: 5db: eb e4 jmp 5c1 <main+0x21>
06:09 PM KitchenMoon: 5dd: 66 90 xchg %ax,%ax
06:09 PM KitchenMoon: 5df: 90 nop
06:10 PM KitchenMoon: Looks like the jmp is non conditional
06:10 PM KitchenMoon: why would it compile like that?
06:10 PM polprog: yeah..
06:11 PM polprog: maybe it makes char signed and detects it will never be 128?
06:11 PM polprog: "The standard does not specify if plain char is signed or unsigned."
06:11 PM KitchenMoon: Have I lost my mind or has my computer :|
06:11 PM polprog: had to ggogle that :v https://stackoverflow.com/questions/2054939/is-char-signed-or-unsigned-by-default
06:11 PM polprog: but assembly never lies
06:11 PM polprog: i think thats what happening
06:11 PM KitchenMoon: oh yeah i should unsign it
06:11 PM polprog: i bet if you put unsigned char there it will do it okay :P
06:11 PM KitchenMoon: ok ill try
06:12 PM KitchenMoon: fixed XD thanks polprog
06:12 PM polprog: :D
06:12 PM KitchenMoon: these things come up somtimes , wow :P
06:12 PM KitchenMoon: it makes sence now
06:12 PM KitchenMoon: but i still cant spell
06:12 PM polprog: yeah, C takes patience sometimes :D
06:13 PM KitchenMoon: yeah, its good medicine
06:21 PM polprog: goodnight!
06:21 PM KitchenMoon: Gnight :)
06:53 PM aandrew: this is kind of nifty.
06:53 PM aandrew: got a two line display now
06:54 PM aandrew: rue_mohr: when sensing the the B-E voltage drop of a transistor (using a constant current source) if I have C-B shorted should that affect anything?
06:54 PM aandrew: basically just an LM334 set to 100uA connected to B, E to ground, and measuring B-E
06:55 PM aandrew: and yes, you're right polprog, the compiler is defaulting to signed char, seeing it'll never be able to hit 128 and optimzing it away
06:55 PM aandrew: -munsigned-char or something like that can flip the default for gcc
06:56 PM aandrew: make
06:56 PM aandrew: er
06:56 PM polprog: what kinda display?
07:08 PM aandrew: me? just a little 128x32 SSD1306 I2C oled
07:09 PM aandrew: https://imgur.com/a/VRsQkxF
08:21 PM ShopMoon: rue_bed2: YouCall??
08:21 PM ShopMoon: rue_mohr: ?
09:05 PM aandrew: ShopMoon: did you figure out your char optimization/
09:19 PM rue_mohr: .
09:19 PM rue_mohr: ShopMoon, maybe, thanks for the help, that worked out great
09:20 PM rue_mohr: in C char is singed
09:21 PM rue_mohr: thats why you should get away from char, int, etc, and use uint8_t and int16_t
09:22 PM rue_mohr: etc
09:22 PM rue_mohr: stdint.h
09:22 PM Tom_L: rue_mohr, what did we scale metric to?
09:22 PM rue_mohr: wavelength of light
09:22 PM rue_mohr: not sure which colour
09:23 PM Tom_L: .03937
10:38 PM rue_shop1: ShopMoon,
10:38 PM rue_shop1: ShopMoon, is this your stove control board?
10:41 PM ShopMoon: nope
10:41 PM ShopMoon: its likely for Russle from James
10:41 PM rue_mohr: ok
10:42 PM ShopMoon: aandrew: yes polprog pointed out I was poking a signing bit by accident :P
10:43 PM ShopMoon: rue_mohr: By the way seems your more right than I thought in what you were sayaing bout antennas
10:44 PM ShopMoon: im seeing diagrams in my book just like your doodle :D
10:44 PM ShopMoon: back to some videos :P
10:56 PM rue_shop1: ShopMoon, AL said something interesting, he said in the half wave dipole, the tap is part of it
11:35 PM ShopMoon: ok, I'll keep that in mind. There IS LIGHTNING AND THUNDER :)
11:35 PM ShopMoon: look outside :D
11:36 PM rue_shop3: yea I know
11:36 PM rue_shop3: lets hope james doesn't get hit
11:36 PM rue_shop3: he went to the mountian
11:36 PM rue_shop3: the thunder always knocks a bunch of rain out of the sky
11:36 PM jymmmm: rue_shop3: You probably already know this, but I found it ineresting... https://www.youtube.com/watch?v=ryJmtItfaXQ
11:36 PM rue_shop3: waiting for the cats to come running in
11:37 PM jymmmm: When the cows come home.... Mooooo
11:37 PM jymmmm: Mooing cats?
11:37 PM rue_shop3: sometimes in the summer I almost forget I have cats
11:51 PM jymmmm: Cause you have tiny cows that meow ;)