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I'm building a USB mouse around a PIC microcontroller and a Pixart mouse sensor. The uC will happily operate on the USB 5V power, but the mouse sensor is picky and wants between 1.8 and 2.1V. Datasheet says it will draw up to 21mA at 1.9V. What's a small, easy way to get 1.9V from 5V? An LM317 seems like overkill (in terms of physical size).
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Dec 23, 2021 23:20
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McMaster-Carr is the place if you want to be sure you're getting exactly the right part, since they've got all the dimensions and options meticulously laid out on their site. I wonder if they'll still send you their massive physical catalog if you ask; I remember using that at my first job, but their website is pretty drat good so I've never missed it except out of nostalgia.
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Jan 10, 2022 17:58
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Foxfire_ posted:SCOPE FIGHT! Trying to decide which scope to order right now. Anyone else have thoughts on the Siglent vs. Rigol DS1054Z? I'm having a hell of a time figuring out why SPI isn't working properly on my PIC, and since some of the SPI pins are also used for in-circuit programming/debugging, I think I'm gonna have to look at the signals directly.
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Jan 24, 2022 18:49
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Shame Boy posted:I have no complaints about the DS1054z, I'm sure the Siglent works fine too, though for debugging SPI you might wanna start with something like a Bus Pirate or one of these cheap-rear end logic analyzers: That analyzer looks great, I'll order one (and probably a scope too). Now I wish I'd have thought to put headers on the PCB for the other SPI pins... ah well I can solder on some leads
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Jan 24, 2022 19:08
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I thought "detent" referred to the "bump" in the middle of the potentiometer range, like on a stereo fader, rather than to an integrated switch?
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Jan 25, 2022 06:20
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Shame Boy posted:I have no complaints about the DS1054z, I'm sure the Siglent works fine too, though for debugging SPI you might wanna start with something like a Bus Pirate or one of these cheap-rear end logic analyzers: Update, this thing + Pulseview kicks rear end. I've been able to verify that the slave device is indeed sending back a value, but for some reason when I read SSPBUF on the PIC it still returns 0. Clearly I'm loving up somewhere... I wish PIC examples online were better, or that the Microchip forums weren't the most hostile place on the Internet.
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Jan 28, 2022 02:07
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When I was doing a lot of soldering as an intern, we had a hole cut in the wall behind my desk with a fan mounted on the opposite side of the hole. On my side, there was a piece of dryer hose attached, so I could pull the hose right next to wherever I was working and suck fumes away. Worked well, but I was 17 so I didn't bother with it as often as I should have.
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Feb 8, 2022 23:44
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Bondematt posted:I just have my windows open and a fan blowing at me. it"s nveer afffectedf me MUch
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Feb 9, 2022 01:29
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Anyone know a source for cables with male USB-A on one end and female Mini-PV/DuPont housings on the other? I ordered https://www.amazon.com/dp/B07ZPT2NMT previously, but the cable is really too short to be practical. I want the cables to be about 4' long. I don't mind making my own, I suppose, but trying to find a decent crimper that's not hundreds of dollars... ugh.
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Feb 10, 2022 00:02
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Lazy solution: Put up a metal railing all around the statue, just far enough away that somebody would have to grab the railing to lean in & touch the statue. The voltage differential between the statue and the railing are left to your discretion. Or, when you think about it, the leyden jar is the original capacitive touch sensor...
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Mar 2, 2022 22:48
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Speaking of Arduinos, what's the smallest option for a USB-capable microcontroller board I can program using the Arduino tools? I've got a USB HID device built around a PIC and I kind of hate the Microchip tools... if I could find something just a tiny bit smaller than the Pro Micro, it would be perfect.
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Apr 26, 2022 22:08
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Shame Boy posted:There's this thing, but it's so small it's kinda getting into the "not all that useful" territory: Perfect size but way too goddamn expensive. I suppose I could just put an ATmega32U4 on the board directly along with the handful of support components it needs, but at a quick look the drat things aren't in stock anywhere. I'll say this about the PIC, at least you can buy them right now for like $2 each.
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Apr 26, 2022 22:21
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namlosh posted:This is incredible, Stack Machine. I had one of those, rescued from my school's loading dock. Unfortunately I knocked it off a shelf and the bakelite just shattered, so watch out for that--they're more brittle than you might think!
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May 3, 2022 21:26
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A Real Happy Camper posted:In my workshop I use a raspberry pi as my shop computer, mostly because it's what I had kicking around that can actually load up plans for projects/play a video or two. I also want to use it to do program arduino stuff. Just download the appropriate ARM tarball (32-bit or 64-bit) from https://www.arduino.cc/en/software and unpack it, I don't think you even need to run the install script just run the arduino binary in the folder it unpacks.
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Jun 3, 2022 20:58
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I'm a dinosaur so I still use a Weller station. Needs are suited.
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Jul 5, 2022 18:27
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InternetOfTwinks posted:Hey y'all, I'm looking to get into electronics to build myself some midi controller/misc input devices, potentially graduating to building my own synthesizer modules and such. Found some plans online and I think I can put some neat stuff together, exciting stuff. There is one issue however, and it's that I have Essential Tremor, ever since I was a kid. This has made my previous attempts at soldering an absolute motherfucker of an experience, even on relatively easy through hole stuff. I'm wondering if there's potentially a model of iron that would reduce the impact my tremors have on the iron, I imagine a short iron would make a huge difference but I wanted to check and make sure they weren't total garbage or something. Maybe reflow soldering is a way to go? Apparently you don't necessarily even need a reflow oven, you can just use one of those hot air desoldering irons? It seems like it would reduce the precision needed quite a bit, although you'll still need to apply the solder paste.
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Jul 5, 2022 20:03
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I've got an old portable computer here with a broken power supply. Tried recapping, no luck. Before I make even more digikey orders, I'm wondering if I might just be better off replacing it with something modern. The only caveat is that it needs to supply +15, +12, -12, and +5 volt levels. Anyone know of a smallish module that could give me what I need out of the box?
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Jul 28, 2022 20:02
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Splode posted:Yeah normally I'd recommend ST for 32 bit microcontrollers, because they're cheap and have a pretty good tool chain. But pretty much their whole range is out of stock at the moment and has been for over a year. My other favourite, the ATMEGA32U4 is also out of stock at this point. I wanted to use the ATmega32U4 for something recently but couldn't find it anywhere. Ended up using a PIC16F1454, and their USB support is a huge pain in the rear end.
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Aug 5, 2022 15:51
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Rescue Toaster posted:Drown the fucker in flux. It's the only way to be sure. This goon knows what's up. I spent two summers doing a lot of SMD soldering, including plenty of itty-bitty ICs with lots and lots of pins. I'd do several large boards in a morning, then work on other stuff in the afternoon. Here's my suggestions: #1 most important: Use flux. Lots of flux. A flux pen is a start, but if you really want to do it right, get liquid flux and a syringe. You put just the gentlest pressure on the plunger and touch the (blunt) needle against the board and the flux just kind of wicks out. If you're installing some godawful 100-pin QFP chip, you really ought to be drag soldering. They make special tips for it, but you can do it just fine with a regular soldering tip too. Put flux on the pads before you set the chip down, then put more flux across the pins when it's in place. Tack down the corners, then get a little solder on your iron or on a corner pin and drag it across the pins on that side. It'll sound like the world's tiniest zipper being zipped. Because you're moving quickly, the component won't be damaged by the heat. Because you've used lots of flux, you're not likely to get any bridging between pins. If you do get a bridge between pins, you can usually just wipe your iron tip on the sponge, apply a little bit of flux to the bridge, then swipe the tip of the iron between the two pins, starting near the body of the chip and moving away briskly. Inspect with a microscope to make sure it's clear. Try a pointy soldering tip. The rounded/wedge-shaped ones are fine for through-hole, but for SMD I prefer a sharp tip. I would run the iron at 700F. Buy the skinniest solder you can find, because it gives better control over quantities. Use a microscope if you can, or at the very least get a pair of those magnifying goggles for soldering. Jeweler's loupes are not worth the hassle. When you're done, the board will be covered in flux. If it isn't, you didn't use enough flux. Run the tap water as hot as you can (we always kept the water heater turned all the way up in the office for this reason) and scrub that bastard with an old toothbrush. When it's clean, shake the water out and put it somewhere to dry. I found the work pretty pleasant once I got used to it. I can't stand paint-by-numbers, but I think the satisfaction I got from properly populating a surface-mount board is probably the same thing normal people get from paint-by-numbers. Best thing about SMD: no flipping the board, and no trimming of loving leads!
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Aug 17, 2022 01:09
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FreeCAD has done the job well enough for my purposes.
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Oct 5, 2022 21:41
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Working on a Raspberry Pi project and I want some attractive indicator lights. Having a hard time tracking down the sort of thing I'm looking for, wondering if anyone might have suggestions:
I'm planning to stuff all this inside a wooden box, so I'm aiming for a more old fashioned look, not a cold modern blue. Ideally I want to find a cheap old (broken) tube radio I can gut and repurpose.
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Oct 10, 2023 21:03
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| # ¿ May 22, 2024 13:57 |
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Shame Boy posted:They probably mean these things: Exactly! It looks like I can just get guitar amplifier pilot lights for about $10 each, but they're 6V incandescent bulbs which is less convenient. I'm also just playing with some cheapo LED panel-mount lights from Amazon to see how bad they are.
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Oct 12, 2023 20:55
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