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Would this circuit work on 5V? Would this circuit work on 5V? I would blow Dane Cook fucked around with this message at 08:08 on Aug 27, 2022 |
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Aug 27, 2022 07:21
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| # ? May 30, 2024 07:03 |
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Just plug it into a simulator to check. I expect you need to change some of the resistor values.
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Aug 27, 2022 08:57
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 I’d have a godawful time wiring that up
Pollyanna fucked around with this message at 15:11 on Aug 27, 2022 |
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Aug 27, 2022 12:11
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Be honest with us. Are you trying to make a Cylon?
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Aug 27, 2022 12:44
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CopperHound posted:Be honest with us. Are you trying to make a Cylon? Maybe
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Aug 27, 2022 14:09
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Looks like it should. Lower the LED resistor value a little
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Aug 27, 2022 16:44
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I tried it and it's working fine on 5V.
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Aug 27, 2022 16:52
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You have to post a photo now.
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Aug 27, 2022 20:34
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Anyone know a really cheap cellphone service/module combo for a project? Either for very small amounts of data or text messages. All the cellular modules from sparkfun/adafruit/etc all are like 3G or GSM and all have big warnings about the networks going away shortly, if not already. There's a couple LTE modules that are very expensive and it's unclear what would be a cheap way to do a plan for those. I could work with custom formats/whatever, I don't need like a RNDIS directly routing packets to the internet. In this case it's just very small occasional packets to/from a remote IoT device (think solar-powered alarm setup in a remote location). Isn't there supposed to be companies partnering w/ 5G cell networks to provide like MQTT/cloud service stuff cheaply, without necessarily full internet access? Where's all that poo poo at! I did see the Blues Wireless stuff: https://www.sparkfun.com/products/17114 Which is real close to what I'm after, but it appears to have no method to send any commands/data whatsoever to the device, it's all data collection from sensors to the cloud, essentially. It would be really nice to have some provision to send messages back. Rescue Toaster fucked around with this message at 21:21 on Aug 27, 2022 |
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Aug 27, 2022 21:11
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I was using ting with a gsm module until recently. It functioned after the 3g shutdown, but I don't know if they will let you add a new gsm device to the network. Unfortunately my gadget was stolen from the location I had it installed about a year ago and I can't tell you if it would still function.
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Aug 27, 2022 21:20
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Rescue Toaster posted:Anyone know a really cheap cellphone service/module combo for a project? Either for very small amounts of data or text messages. All the cellular modules from sparkfun/adafruit/etc all are like 3G or GSM and all have big warnings about the networks going away shortly, if not already. There's a couple LTE modules that are very expensive and it's unclear what would be a cheap way to do a plan for those. I could work with custom formats/whatever, I don't need like a RNDIS directly routing packets to the internet. This will depend heavily on which country you are in, but in quite a few countries they are rolling out or have rolled out IOT specific cellular technologies like NB IOT and CAT M1. See if you can find a module for those, it should be much cheaper both for the module and for the data plan
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Aug 28, 2022 05:21
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ante posted:Looks like it should. Lower the LED resistor value a little so like a 220 ohm instead of a 330 ohm?
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Aug 28, 2022 07:23
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Oh, it looked like there was a "k" there on mobile, meaning a much higher resistor Don't worry about it, you're fine, just YOLO it
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Aug 28, 2022 07:26
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Yeah if you're happy with the brightness at 5V then you're good to go.
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Aug 28, 2022 12:25
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If you want it to be about the same brightness as 12V, 82 ohms is reasonable assuming red LEDs with a 2V forward drop. It looks like the original design is putting around 30mA through the LEDs.
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Aug 28, 2022 14:15
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Stack Machine posted:If you want it to be about the same brightness as 12V, 82 ohms is reasonable assuming red LEDs with a 2V forward drop. It looks like the original design is putting around 30mA through the LEDs. I was about to say that's way too much current for an LED but it's actually sets of two LED's in parallel so each one's only getting ~15mA which is fine I guess. I usually keep LED's in my designs at or below 10mA so they'll last forever, and modern LED's still tend to be really bright at that current.
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Aug 28, 2022 14:43
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Thanks guys
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Aug 28, 2022 15:14
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Working with perfboard is kind of awful, I’m not gonna lie. Your choices for connecting all the individual holes is smearing solder everywhere (doesn’t work if you solder correctly) or cutting and soldering a bunch of wires for jumping (annoying). I’ve found stripboard/veroboard to be a more natural evolution from breadboards, cause the tracks are a lot more familiar. Translating circuits from schematic to stripboard hurts my head, though. I’m too much of a perfectionist so I can never hit a good balance between a clean design and a compact one  any tips? The advice I’ve seen so far is mainly “choose one component as the center of the circuit” and “designate some of the tracks as power rails”.I’m also realizing that some circuits are complex enough and have common enough sub parts that I could just modularize them. Draw up some independent schematics that e.g. input +12/-12/GND and output +5/+2.5/+4.5/-12/GND, for example. Maybe I’ll make a circuit with that and add some screw terminals for power? Does that make sense? Would be a pretty simple three-resistor voltage divider. Unless there’s a better way to split +12V into +5V and +2.5V.
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Aug 29, 2022 14:47
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I like stripboard a lot too. I start in the upper left with my signals coming in and I lay it out from that corner outward while planning to cut as few traces as possible. I cut the traces with a drill bit held in my hand, pressing it into the board centered on a hole and then I turn it a a couple of rotations. It scrapes the copper off in a circle centered on the hole. Here's the parallel port-I2C adapter I made:  For more complicated stuff nowadays it's probably better to lay out the board in software and have it made and mailed to you, but I like having parts and stripboard so I can whack something together fast when I feel like it.
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Aug 29, 2022 15:02
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I’m not experienced enough to design my own PCBs, so I’m sticking with board for now. Maybe later! That sounds like a good approach. I may do the same.
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Aug 29, 2022 15:16
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May I humbly suggest trying this technique?   Chip shortage? No problem. Cracker shortage? Big problem. 
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Aug 29, 2022 20:58
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Cory Parsnipson posted:May I humbly suggest trying this technique? So this is the bread board I've heard so much about
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Aug 29, 2022 22:03
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I'm too lazy to plan everything out on strip board, so I often just do perf board and make a big soldery blobby mess when I need to connect lots of things. It's not something I'd want to RF or audio circuits on but it works and I can just start doing it without too much pre planning
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Aug 30, 2022 02:09
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I just make PCBs for everything these days. Peak laziness / hubris. Spend twenty minutes tossing it on a small breakout board, leave it large and bodgeable, pay the $5 to add it on to others I already have in the cart, and it'll be here in a week. It's magic, really. The advantage is that when I'm ready to incorporate it into a real design, the layout and footprint is already done
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Aug 30, 2022 02:34
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That's a great way of doing it. It really is getting affordable now, I'm looking at putting together a DIY pedal for a mate and it'll be just $50 for 5 4 layer PCBs, with shipping. Way less if I can go for 2 layers, but it's audio so we'll see how the layout looks. What do you use for your PCB design? I have exclusively used Altium at work but I'm going to try KiCAD for the first time for this project.
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Aug 30, 2022 03:06
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I used Altium professionally for a long time, and found KiCad quite familiar and usable. It was missing a lot of quality of life features, but that list is rapidly shrinking with the latest update. In short, they're killin' it.
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Aug 30, 2022 03:09
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Splode posted:That's a great way of doing it. It really is getting affordable now, I'm looking at putting together a DIY pedal for a mate and it'll be just $50 for 5 4 layer PCBs, with shipping. Way less if I can go for 2 layers, but it's audio so we'll see how the layout looks. How big are the PCB's because I just got 5 4-layer boards from JLC for way less than that, shipping included
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Aug 30, 2022 03:12
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Shame Boy posted:How big are the PCB's because I just got 5 4-layer boards from JLC for way less than that, shipping included Tiny, I estimated 5 by 10 cm. I'll switch to JLC, thanks!
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Aug 30, 2022 05:35
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pcbshoper.com will do price comparisons among all the various may-actually-be-the-same-place-behind-a-different-storefront sketchy Chinese PCB shops + a few other small batch places at various shipping speeds. (JLC is the current winner for cheapest possible five 5x10cm 4 layer at $7 for boards and $8 for slow shipping, but it'll take 3 weeks to get to the US)
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Aug 30, 2022 06:03
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I grew up with stripboard (it seemed very common in the UK, everyone used it, when I came to the US it seemed like everyone used perfboard and I had no idea why. It seemed even worse than wirewrapping, which at least has a little tool and doesn't involve soldering onto a tiny pad). I've definitely started just ordering $3 runs of 10 PCBs from China or whatever if it's something with a bunch of wiring up to do (like recently I made a breakout board to plug the pod cables from an early '90s HP logic analyser, which were meant to plug straight into your 486 motherboard or whatever you were trying to analyse that would have the actual probe circuits built in, so I could just turn them into individual probes. 96 of them, in fact, via 12 separate PCBs). I do still occasionally use stripboard for super simple things (like a traic to operate a contactor, or just hook up a 5V regulator and springed connector to a thing I 3D printed for my ebike to get power out of the "proprietary lighting system"). I don't really "plan" it though, I just kind of imagine how it should all work out perfectly, cut it out to be just the right size, make a couple of annoying mistakes, then it mostly works. I did once try something a little more ambitious, when I was around 12 years old:  It's an attempt to build a Z80 computer, entirely on stripboard. There's buses and things in there, in the mess of wires. It had a separate I/O board meant to drive the keyboard recovered from an old trashed BBC Micro. It didn't work at all, but I borrowed an ICE from my dad's work (an old one - it was a long, narrow box filled with PCBs that ran the full length of it, with a pile of ribbon cables that ran out to a "pod". You could swap out the pod and its interface board inside the box for different CPUs, and it had an extremely delicate connector on a ribbon cable that came out of the pod that would plug into the CPU socket on your system. You then controlled it via a command line interface on an RS232 port on the back of the box). It told me multiple lines on all of my buses were tied together, after which I was filled with a kind of despair and never tried it again.
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Aug 30, 2022 09:10
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Anyone ever do wire wrapping?
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Aug 30, 2022 10:50
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I would blow Dane Cook posted:Anyone ever do wire wrapping? For looks/fun yes…professionally for like EMI/anti abrasion reasons not really but I know a little bit
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Aug 30, 2022 11:40
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CarForumPoster posted:For looks/fun yes…professionally for like EMI/anti abrasion reasons not really but I know a little bit got any cool photos?
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Aug 30, 2022 11:44
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I still etch my own boards sometimes because I'm a weirdo who likes fiddling around with things and also instant gratification. Never been able to get that film photoresist to apply to copper clad properly though so I gotta buy the more expensive presensitized stuff. At least it works really well.
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Aug 30, 2022 13:41
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ante posted:I just make PCBs for everything these days. Peak laziness / hubris. Spend twenty minutes tossing it on a small breakout board, leave it large and bodgeable, pay the $5 to add it on to others I already have in the cart, and it'll be here in a week. It's magic, really. Yeah if you can batch up 2-3 orders to break down the shipping it's almost insane not to use them. I mean 10cm x 10cm 2 layer boards are literally $2 from jlcpcb for qty 5. If you get in the habit of bringing out all the extra pads, leaving gaps where you can cut traces, etc... and stay away from fancy soldermask colors so you can easily see the traces, it's trivial to repair/modify usually or re-use portions of boards for other things. Once you have Kicad kind of setup the way you want, with standard trace sizes you use a lot and such, it's super fast. Remember a lovely PCB layout is still probably going to perform better than the best breadboard you could possibly setup no matter how careful you are, and after a little practice with kicad it'll be even faster. The REAL skill to learn is to add library parts and find existing pinouts that are close and you can use with minor modifications, that's where most of the time is spent I find if I'm throwing together a quick breakout board or test for some analog circuit. Also keep your past gerbers/projects bundled up and ready to go so if you're placing an order and realize you need some more X-bee to 0.1" breakouts or whatever, just throw them in there and soak up more of that shipping.
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Aug 30, 2022 14:49
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Yeah, stripboard seems good for relatively simple projects and circuits, but I find that anything that requires a lot of branching paths and complex serialization is kind of a pain. I’m still trying to translate this to stripboard: And kinda beefing it! The 5-6 and 13-14 complexes in particular are mind bending. I might save the capacitors-to-ground (what are those called again) for last since they’re relatively simple.
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Aug 30, 2022 15:05
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Shame Boy posted:I still etch my own boards sometimes because I'm a weirdo who likes fiddling around with things and also instant gratification. I tried making my own PCBs a few times in the 2000s, as I had much less money and Chinese cheapo PCBs were less of a thing (or at least, less obviously a thing I had access to). I tried the photoresist once or twice but ended up just using a laser printer on photo paper (there's also a dedicated product meant for this but plain photo paper worked better), using a clothes iron to transfer the toner. I even managed to do double sided a couple of times this way, though it took a few attempts to get the toner nicely aligned (I'd predrill a couple of alignment holes that had matching holes on the PCB image, so once it was transferred I could visually confirm. If you made a mistake you could just wash the toner off with acetone, re-clean the copper and try again). I also used ammonium persulphate as it remained nice and transparent throughout the process. It also turns a lovely blue as it absorbs the copper.
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Aug 30, 2022 18:52
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Charles Ford posted:I tried making my own PCBs a few times in the 2000s, as I had much less money and Chinese cheapo PCBs were less of a thing (or at least, less obviously a thing I had access to). I tried the photoresist once or twice but ended up just using a laser printer on photo paper (there's also a dedicated product meant for this but plain photo paper worked better), using a clothes iron to transfer the toner. I even managed to do double sided a couple of times this way, though it took a few attempts to get the toner nicely aligned (I'd predrill a couple of alignment holes that had matching holes on the PCB image, so once it was transferred I could visually confirm. If you made a mistake you could just wash the toner off with acetone, re-clean the copper and try again). Yeah I used the toner transfer method for a while but it would always leave the board kinda messy and there were always lots of flaws. And yeah I just tried ammonium persulfate for the first time on the last board I did, worked way better than I expected. Definitely using it going forward.
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Aug 30, 2022 18:58
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ante posted:I just make PCBs for everything these days. Peak laziness / hubris. Spend twenty minutes tossing it on a small breakout board, leave it large and bodgeable, pay the $5 to add it on to others I already have in the cart, and it'll be here in a week. It's magic, really. And then there's me, on month, like, 4 of putting off ordering a PCB because I'm afraid I might have goofed something up in my design. The first time is always scary, I suppose.
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Aug 30, 2022 19:45
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| # ? May 30, 2024 07:03 |
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Gotta just YOLO it
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Aug 30, 2022 19:58
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