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Pollyanna posted:Check out this blank-rear end wall. Here's a thing I made: https://i.imgur.com/KQ3rDND.mp4 Here's the source code: https://git.woozle.org/neale/wallart And here's the source code to the optional animation server I made so I can send my daughter little things when she's away in college. https://git.woozle.org/neale/wallart-server cruft fucked around with this message at 03:05 on Nov 6, 2022 |
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Nov 6, 2022 03:03
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Does anyone know of a good way to find the biggest batty cell that would fit in a given volume? The volume is fixed (existing laptop) and custom sizes aren't an option since I'd only need 2 cells. I know I can just search aliexpress but it's basically trial and error. And I tried digikey but the sizes aren't separate dimensions I could filter independently so that blows.
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Nov 6, 2022 21:20
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Oof... SM8 is not the same as SOIC-8... And only one company still manufactures a PCA9306 in SOIC-8 form factor. Thankfully it's still in stock at one distributor and only cost me $10 for extra shipping. It could have been new PCB time... The lesson is: double-check the package information listed by digikey and mouser. They're good but not perfect.
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Nov 6, 2022 22:08
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mobby_6kl posted:Does anyone know of a good way to find the biggest batty cell that would fit in a given volume? The volume is fixed (existing laptop) and custom sizes aren't an option since I'd only need 2 cells. Take your measurements, and turn it into a part number: https://www.batterylipo.com/lipo-battery/ With the caveat that not all part numbers will actually exist. Then, search AliExpress for that part number. Actual battery capacities will be maybe ballpark, but largely made up, so just assume that bigger=better in most cases
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Nov 6, 2022 22:29
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ante posted:Take your measurements, and turn it into a part number: Thanks! Seems like there are only a couple candidates and they don't overlap much with what's available on ali. This one would've been perfect if it was like 55mm wide too for example, though it would do if it comes to it.  The capacities are... yeah. All over the place. I'm not too optimistic about them being accurate but OTOH if this one had the (claimed) density of the stock battery, it would've been 6Ah. So maybe 5Ah is in the ballpark at least, I've had decent success with drone LiPos performing as expected before. E: Could anyone ID the type of these white connecctors? I mean the type of socket... I'm quite sure at this point at least one of them near the heatsink is for a fan, which I want to install there mobby_6kl posted:I've been looking at the internals of my cheap Chinese laptop and it's pretty interesting what's left inside mobby_6kl fucked around with this message at 14:24 on Nov 9, 2022 |
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Nov 7, 2022 01:49
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Is there truly nowhere to get a Raspberry Pi Zero W or a Pi 4 for under $150? I finally have 2 project ideas but lol at spending that much money on a simple SBC
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Nov 12, 2022 17:45
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I think if you search back in the thread, Shame Boy posted a link to a site that tracks which places have Raspberries Pi in stock and at what price
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Nov 12, 2022 17:52
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Sagebrush posted:I think if you search back in the thread, Shame Boy posted a link to a site that tracks which places have Raspberries Pi in stock and at what price Oh thanks, that's a good tip. e: nope, out of stock everywhere Sir Bobert Fishbone fucked around with this message at 18:08 on Nov 12, 2022 |
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Nov 12, 2022 18:01
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Yo have to keep watching it, but it likely will never get better as everyone wants one.
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Nov 12, 2022 18:38
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A truly dire time for people with dumb ideas who finally have a little free time on their hands
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Nov 12, 2022 18:52
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I know how you feel. I had to pay double for a RPi 3A+ to use for my senior design project.
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Nov 12, 2022 19:18
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I watched it for a week and was able to buy two Zero 2 Ws for $15 each back in Januaryish. No idea what's happened in the year since, though.
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Nov 12, 2022 19:22
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I put one of these together today   Hardest part was the decorative legs. The soldering was just tedious.
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Nov 12, 2022 19:35
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I actually have an rpi4 that I think I'm ready to admit I'm not going to end up using that I could probably part with.
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Nov 12, 2022 23:09
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Pollyanna posted:I put one of these together today Shout out to evil mad scientist labs and their customer support. I have their X-Y plotter for signing Christmas cards the professional way and it owns.
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Nov 12, 2022 23:11
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Yeah I finally have a use for Pi's for the first time in my life and now they will never be in stock ever again. Did at least pick up some compute module 4's before those went out of stock though so that's nice.
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Nov 12, 2022 23:20
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A Proper Uppercut posted:I actually have an rpi4 that I think I'm ready to admit I'm not going to end up using that I could probably part with. Let me know if you make a decision! I have buttons, screens, and ADCs for days but I'm trying to build a little device to make it easier to digitize my 78rpm record collection. When I get a Zero W I'm going to gut and replace the internals of a lovely useless cloud-based automatic cat feeder that apparently lost its servers a while back.
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Nov 13, 2022 00:46
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If it's just a cat feeder you might be able to use an esp32 board instead.
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Nov 13, 2022 03:32
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Splode posted:If it's just a cat feeder you might be able to use an esp32 board instead. Yeah but there's a camera on it that I'm hoping to bring back to life too. Might end up starting with one of my ESP32s for basic functionality in the interim.
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Nov 13, 2022 03:41
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There's ESP32 camera boards but I tried one with RTSP streaming and while the picture is pretty good it's low FPS and has a couple of seconds of delay over wifi. Pretty cool for like $9, though.
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Nov 13, 2022 06:34
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Yeah I have an ESP with the camera module and I think it would be perfectly fine for the purpose of cat monitoring. I've used it to take hourly shots and upload them to aws though. Also, probably should've posted this yesterday when I bought it on sale but it was like 2am so... there's a USB-C thermal camera that unlike most other budget ones is 256x192 and comes with an detachable macro lens, which makes it actually useful for electronics. It was like $50 less yesterday so maybe keep an eye on it https://www.aliexpress.com/item/1005004740419275.html
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Nov 13, 2022 14:35
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I just mailed my Pi Zero W to a friend who needed one to bootstrap a PDP-7 he's got one of his college classes restoring. I was sad to see it go, even though it had been collecting dust on a shelf, and even though I know bootstrapping a PDP-7 is a far more heroic job than any stupid task I could have dreamed up for it.
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Nov 14, 2022 00:41
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Oh man, I must still have a Zero W sitting somewhere, I set it up for Pi Hole a few years ago and haven't seen it since  had to actually check my DNS settings to find its ip and then ping it, seems to be still working lol.
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Nov 14, 2022 14:46
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Dear friends Some months ago I asked some assistance to figure out the currents in this circuit  It's an open source PIC programmer available here. It's an old project but it looks simple and, after reading the source code a bit, it seems like I could eventually expand on it. However, I am not making it work. I did and rechecked the circuit in the breadboard a bunch of times and ended up shelling out for a good breadboard. I realized that it was written for the Raspberry 2 and mine (a 4B) uses a different microprocessor, so I had to change the base address for peripherals. After checking the circuit and everything several times, I am at a loss. The circuit seems to check out (currents and stuff), and I have checked the wiring a thousand times, to put everything in the correct pin. So three questions: - Where and how should I continue debugging? Where should I look? How do I overcome the problem that there are several moving parts and I dont know which one is broken? - The github repository has an updated version of the circuit, you can find it here. It has a jumper J1 across the Q7 transistor. What's the point of that? - Is there a better maintained, more modern project that does what I want it to? (Program pics with my raspberry or computer) Thank you in advance. VVV Thanks a million, you are cool. Will do. Dawncloack fucked around with this message at 11:53 on Nov 16, 2022 |
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Nov 15, 2022 12:59
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Dawncloack posted:Dear friends The best thing to do would be to get an oscilloscope on the PIC pins and see if they're getting the expected waveforms when you run the code to program it. If you don't have an oscilloscope, you could learn a lot just by adding an LED to each pin (with it's anode on the GPIO and its cathode on a 10k resistor with its other lead grounded, so it lights when the signal is high). That way you can at least determine whether anything is happening at all and whether all of the pins are changing. If you have source code for the part that runs on the Pi, you can also add delays (say, a call to sleep(1) each time you change a signal). Then it becomes possible to do things like check VPP with a multimeter and make sure it's at the appropriate value.
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Nov 15, 2022 15:29
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Sagebrush posted:I think if you search back in the thread, Shame Boy posted a link to a site that tracks which places have Raspberries Pi in stock and at what price Thanks again for this, just snagged a Zero 2 W!
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Nov 17, 2022 18:02
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I have no memory of posting that and can't find it in my own post history, mind linking it again
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Nov 17, 2022 18:38
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Shame Boy posted:I have no memory of posting that and can't find it in my own post history, mind linking it again Lol https://rpilocator.com/
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Nov 17, 2022 18:54
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Thanks, bookmarking it this time
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Nov 17, 2022 18:57
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Is there an electronics repair thread? I have a ~20yo home stereo reciever that has started making a 60Hz buzzing noise. I am confident that it's not a ground loop: it is physically vibrating the chassis.
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Nov 18, 2022 02:20
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Skinnymansbeerbelly posted:Is there an electronics repair thread? I have a ~20yo home stereo reciever that has started making a 60Hz buzzing noise. I am confident that it's not a ground loop: it is physically vibrating the chassis. Not sure if there's a dedicated thread but plenty of people post in here about it so it's fine if you wanna. That sorta sounds like a transformer inside might have come a little loose, they vibrate a tiny bit normally due to a phenomenon called magnetostrsiction, and if the screws holding em' down back out a bit they can start rattling.
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Nov 18, 2022 03:36
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You made that word up.
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Nov 18, 2022 04:00
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Cojawfee posted:You made that word up. You're right! The actual word is magnetostriction and I added an extra S for some reason.
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Nov 18, 2022 04:02
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fun fact that is what causes coil whine... the magnetic field shakes toroids on the pcb as the circuit cycles at its frequency as they charge and uncharge. there is also cap whine in LCD screens...
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Nov 18, 2022 04:05
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It is also the same effect that makes the high-pitched whistle of a camera flash charging up, the whine of an old TV, and the buzzing and clunking noises in MRI machines, among many more sounds.
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Nov 18, 2022 04:10
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I have a little electronic chess game with a weird issue. The first time you flick the switch to turn it on after not having used it for a while it will take some time to turn on (leds lighting up, speaker beeping). If you turn it off and back on again right away it will then start up right away. It's like there's something that needs time to charge up in there. I replaced the only electrolytic cap on the board but it's still happening. Any ideas? It's not a battery thing because it does it with the mains adapter too.
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Nov 18, 2022 04:30
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I would blow Dane Cook posted:I have a little electronic chess game with a weird issue. The first time you flick the switch to turn it on after not having used it for a while it will take some time to turn on (leds lighting up, speaker beeping). If you turn it off and back on again right away it will then start up right away. It's like there's something that needs time to charge up in there. I replaced the only electrolytic cap on the board but it's still happening. Any ideas? Did it used to not do this?
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Nov 18, 2022 06:52
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Splode posted:Did it used to not do this? I only just got it. It's like from 1981 though.
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Nov 18, 2022 07:21
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It may be totally normal for it to do that. What you've described does sound like a capacitor charging up, and retaining a charge for a short time after being powered off. Perhaps it is a power supply filtering cap. Maybe the device is so old that its mains adapter is only half-bridge rectified, or isn't at all? If the slow charging is the normal behavior, of course replacing it won't do anything. Hard to say without seeing the circuit obviously. How many farads is this capacitor?
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Nov 18, 2022 08:08
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I don't think the capacitor is the issue, there's probably something limiting the current into the device that results in the capacitor taking a bit longer to charge. Given it is from the 80s, it may just be that way.
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Nov 18, 2022 10:42
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