#avr Logs

Sep 04 2019

12:02 AM day__ is now known as day
12:52 AM rue_bed: djph, chineese rotary switch?
01:08 AM cehteh: djph: debounce ftw, esp rotary encoders
01:45 AM Maya-sama is now known as Miyu
02:49 AM polprog: painting some plastic scrap to get the drill.of it
02:49 AM polprog: looks like shit after the first layer but im at the third one now and it starts looking okay
02:50 AM polprog: rue_bed: any spray tips?
02:54 AM Smidge204: Try filler primer followed by a light sanding
06:05 AM polprog: looks like 5 thin layers did the job well
06:05 AM polprog: i could try putting on 1 layer of matte white beforehand (its black plastic) but the coverage is pretty good
06:48 AM djph: cehteh: nah, its a counter in a loop ...
06:49 AM djph: polprog: did you prime it?
06:49 AM polprog: nope
06:49 AM polprog: i wiped it with ipa
06:49 AM djph: polprog: what kind of plastic?
06:49 AM polprog: i dont think they sell primer for this kinda plastic
06:49 AM polprog: paint*
06:50 AM djph: what kind?
06:50 AM djph: petg, pla, abs ... something exotic?
06:50 AM polprog: plastic is ABS, paint is rc car colors for polycarbonate (not abs, ikr)
06:51 AM djph: acrylic paint then?
06:52 AM polprog: https://i.ibb.co/sVZWZ3y/IMG-20190904-134613.jpg
06:52 AM polprog: no idea. doesnt say
06:52 AM polprog: looks kinda acrylic
06:52 AM polprog: (i have acrylic marker and the behavior of the paint is similar)
06:52 AM djph: cleans with water?
06:53 AM polprog: yes, while still wet
06:53 AM djph: ok, thats acrylic then.
06:53 AM polprog: (got some of it on the tiles, had to mop up)
06:53 AM polprog: cool, thanks for letting me know
06:53 AM djph: get yourself any spraypaint primer that cleans with mineral spirits
06:54 AM polprog: i think it doesnt say on the can
06:54 AM polprog: any good brand?
06:54 AM djph: I'm a fan of the "self etching" automotive stuff for metals
06:54 AM djph: krylon, rustoleum, etc.
06:55 AM polprog: hmm there is motip primer available cheap
06:55 AM polprog: it should work on metal as well if its acrylic right?
06:55 AM polprog: with primer
06:56 AM djph: basically the stuff is thinned with one of the fun chemicals (mek, xylene, etc) that attacks ABS
06:56 AM polprog: interesting
06:57 AM djph: so it melts the surface just enough for the primer to stick, then the primer gives "tooth" gor the other paint to stick to.
06:57 AM polprog: okay
06:57 AM polprog: thanks, gtg
06:57 AM polprog: ill get some primer then
06:58 AM djph: take care
08:48 AM MrFahrenheit: https://cdn.discordapp.com/attachments/410511637196570631/618799305918251009/IMG_20190904_152517.jpg
08:49 AM MrFahrenheit: now I gotta drill all those holes, ugh, through hole sucks so much
08:54 AM Fuchikoma: DIY solder resist?
09:01 AM MrFahrenheit: yeah
09:04 AM Fuchikoma: I have some of that stuff in a syringe tube but havne't gotten around to trying it out yet. Seems like you got a good result though
09:05 AM Fuchikoma: I'm wondering if there's a film version instead of a liquid you have to spread on
09:05 AM MrFahrenheit: it would be better with a film, yes, it's annoying to spread it, and even more annoying to wash it
09:06 AM Fuchikoma: That's encouraging
09:07 AM MrFahrenheit: I think there is a film version though, you apply it with a laminator
09:07 AM MrFahrenheit: or I might be thinking of photoresist
09:08 AM Fuchikoma: yeah
09:08 AM Fuchikoma: I use a film etch resist so a film solder mask would be really noce to go with it
09:15 AM MrFahrenheit: it does seem to exist, dynamask
09:15 AM MrFahrenheit: bit pricey though
09:35 AM vmt: would rather get boards made than buy that, if you need solder mask
09:38 AM Fuchikoma: I generally don't bother with resist on home etched boards but it seemed like a neat thing to try
09:38 AM Fuchikoma: For like $6 or whatever a tube of UV cure gel cost why not give it a go
09:45 AM polprog: MrFahrenheit: what a cute board
09:45 AM polprog: whats that for?
09:46 AM polprog: looks like some HV stuff
11:16 AM djph: qx
11:16 AM djph: ...
11:17 AM MrFahrenheit: it's a triac based dimmer intended to be driven by a microcontroller on the other side of the isolation
11:17 AM Fuchikoma: Leading or trailing edge? :P
11:21 AM cehteh: datasheet?
11:21 AM MrFahrenheit: leading edge, can't do trailing with a triac
11:21 AM MrFahrenheit: and it's gonna be a resistive load so it's the same, really
11:21 AM Fuchikoma: k
11:23 AM Fuchikoma: Just thought if you were going through the trouble of adding a uC might as well get extra fancy, but I suppose you already made the PCB anyway
11:24 AM MrFahrenheit: well I was gonna go with mosfets which lets you decide in software if you wanna do leading or trailing edge, but then I found that all my hv mosfets suck so I went with a triac
11:25 AM cehteh: how about a SSR?
11:25 AM MrFahrenheit: well this is pretty much an ssr
11:25 AM Fuchikoma: That's literally just a triac with *maybe* build in zero-cross.
11:26 AM Fuchikoma: And if it has built in zero cross that defeats the dimming part
11:26 AM MrFahrenheit: yeah
11:26 AM cehteh: and optoisolation and whatever else is necessary, differneces arent big, but you get some confort less parts
11:26 AM MrFahrenheit: although cycle skipping still works if your load is slow
11:26 AM cehteh: some SSR's have zero cross some dont
11:26 AM cehteh: buildin snubbers sometimes as well
11:27 AM cehteh: if possible i'd go for SSR first, just to make it easier
11:28 AM Fuchikoma: Again, you'd need to make sure it's one WITHOUT zero-cross
11:28 AM cehteh: depends on the load
11:29 AM cehteh: sometimes thats desireable, aka i used zero cross ones for my oven
11:29 AM Fuchikoma: He's making a dimmer
11:29 AM Fuchikoma: So it's kind of relevant that he be able to switch on mid-cycle
11:29 AM cehteh: when he wants to dim light and dont want flicker
11:30 AM Fuchikoma: If the SSR waits for the next zero-cross that defeats the dimming function for basically anything between 50% and 100% power levels.
11:31 AM cehteh: for my oven i have a 10 sec cycle divided into 20ms parts, no sync to phase, 50hz here so zero cross roughly does the job, the rest is some not noticeable aliasing
11:32 AM cehteh: blinking a lamp at 0.16Hz may be a bit odd :D
03:33 PM MrFahrenheit: works https://i.imgur.com/rOgGco3.jpg
03:34 PM MrFahrenheit: though I'll probably do another board, I don't like a few tiny things
03:51 PM Smidge204: That certainly looks the business
03:52 PM Smidge204: Nice build
03:57 PM MrFahrenheit: thanks
04:42 PM nohit: MrFahrenheit: nice