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Cojawfee posted:I've been comparing the two and it seems like the Siglent is nice but if you want the logic analyzer, you're paying 400 bucks on the siglent vs 200 with the Rigol. Yeah but don't forget the $350 Rigol doesn't support the logic addon at all. You have to pay about $100 extra for the model that supports adding a logic analyzer. The 4x100Mhz that supports it lists for $500. Still a cheaper path to logic analyzing than Siglent but kind of annoying. The difference is that Rigol puts the logic FPGA in the scope (or not). Siglent provides a high speed accessory port and puts everything in the accessory dongle. That also means the Siglent solution is clunkier. Oh I forgot Siglent forces you to pay $100 to unlock the logic feature on any scope...so that's pretty annoying too (the logic hardware has come down to $329 FWIW). asdf32 fucked around with this message at 15:24 on Nov 29, 2019 |
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Nov 29, 2019 15:06
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Rexxed posted:Even the Pi 4B has composite out but it's part of the TRRS audio jack, one of the conductors is composite video. They turned it off by default in the image but you can re-enable it in the config.txt and use it with the right cable: To clarify: I don't need the power of a pi4 (or a pi 3 or probably a 2 even), and I'm trying to not spend $35 per unit when I need 1-2 dozen of them
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Nov 29, 2019 16:33
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moron izzard posted:To clarify: I don't need the power of a pi4 (or a pi 3 or probably a 2 even), and I'm trying to not spend $35 per unit when I need 1-2 dozen of them https://magpi.raspberrypi.org/articles/rca-pi-zero
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Nov 29, 2019 18:06
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I know how to get composite out I don't know how to purchase more than 1 zero or zero w at a time
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Nov 29, 2019 23:24
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Arrow electronics has 29 RPI-029 (wifi) and 184 RPI-030 (no wifi) in stock but thats all I could find.
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Nov 29, 2019 23:48
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I learned to etch PCBs in high school electronics class, I can build simple circuits on my own, and I'm looking to work with custom designs. I see there are acid etching machines on eBay that I wouldn't trust to hold deionized water, nevermind ferric chloride. Have any of you ever worked with the mini CNC machines branded as PBC etchers and had a decent experience? I'm looking to build a jukebox that uses a CRT as the screen and maybe a plasma tweeter for treble, and the tolerances on some DIY and Instructables designs are alarming and I'd like to split them up entirely with opto-isolators.
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Nov 30, 2019 01:23
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What's your goal? Generally, I'd just recommend sending them off to China. It'll end up being cheaper, higher quality, faster (at first) and less stressful. If you want to do it for its own sake, that's different
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Nov 30, 2019 01:56
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GWBBQ posted:I learned to etch PCBs in high school electronics class, I can build simple circuits on my own, and I'm looking to work with custom designs. I see there are acid etching machines on eBay that I wouldn't trust to hold deionized water, nevermind ferric chloride. Have any of you ever worked with the mini CNC machines branded as PBC etchers and had a decent experience? I'm looking to build a jukebox that uses a CRT as the screen and maybe a plasma tweeter for treble, and the tolerances on some DIY and Instructables designs are alarming and I'd like to split them up entirely with opto-isolators. I’ve watched some videos of diy cnc pcb etching and it seems really awful (toms3d and tech2c on YouTube have both covered it) Not speaking from personal experience but it seems either acid etched copper clad or farm the pcbs out to an online fab are the ways to go
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Nov 30, 2019 01:57
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GWBBQ posted:I learned to etch PCBs in high school electronics class, I can build simple circuits on my own, and I'm looking to work with custom designs. I see there are acid etching machines on eBay that I wouldn't trust to hold deionized water, nevermind ferric chloride. Have any of you ever worked with the mini CNC machines branded as PBC etchers and had a decent experience? I'm looking to build a jukebox that uses a CRT as the screen and maybe a plasma tweeter for treble, and the tolerances on some DIY and Instructables designs are alarming and I'd like to split them up entirely with opto-isolators. I have a 3018 CNC and using the included bits can etch some pretty tight tracks. Takes some cleanup afterward and makes fiberglass dust like OSHA is defunct. With a set of drill bits, it does through-hole just fine. Haven't tried any surface mount layouts smaller than 0603 and haven't tried any vias, but normal surface-mount stuff cuts fine.
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Nov 30, 2019 03:04
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GWBBQ posted:I learned to etch PCBs in high school electronics class, I can build simple circuits on my own, and I'm looking to work with custom designs. I see there are acid etching machines on eBay that I wouldn't trust to hold deionized water, nevermind ferric chloride. Have any of you ever worked with the mini CNC machines branded as PBC etchers and had a decent experience? I'm looking to build a jukebox that uses a CRT as the screen and maybe a plasma tweeter for treble, and the tolerances on some DIY and Instructables designs are alarming and I'd like to split them up entirely with opto-isolators. We have a T-Tech Quick Circuit 9000 CNC system at work, really the only advantages to it over sending out the boards to some OSH Park type service is that (1) you can get the boards made faster, like hours instead of weeks, and (2) you can use the CNC aspect in other ways such as making cosmetic front panels or purely mechanical structures. The downsides are that they're fairly finicky and labor intensive - you will have to sit there with it and baby it along while it makes the part not just hit 'go' and come back in two hours, you have a max of two layers that don't always have great alignment between them, there are no conducting vias, tolerances are just generally shittier, there are no solder mask/silk screen layers, no gold plating, and there is a lot of noise and fiberglass dust generated during the CNC process. Also the bits wear out pretty quickly and are expensive. So yeah, I'd just send boards out unless you really need same-day turnaround or just like playing with CNC systems (which is understandable, they're pretty fun to play with especially if work is paying for it).
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Nov 30, 2019 03:38
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GWBBQ posted:I learned to etch PCBs in high school electronics class, I can build simple circuits on my own, and I'm looking to work with custom designs. I see there are acid etching machines on eBay that I wouldn't trust to hold deionized water, nevermind ferric chloride. Have any of you ever worked with the mini CNC machines branded as PBC etchers and had a decent experience? I'm looking to build a jukebox that uses a CRT as the screen and maybe a plasma tweeter for treble, and the tolerances on some DIY and Instructables designs are alarming and I'd like to split them up entirely with opto-isolators. I can't imagine buying one, unless I expect to get into a situation where the shipping time for a fab is unacceptable.
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Nov 30, 2019 03:49
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What's the pcb cost comparison site?
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Nov 30, 2019 03:59
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pcbshopper dot com
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Nov 30, 2019 06:32
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So I mentioned it in a previous post, but I've finished* repairing the old radar gun detector I picked up from ebay. I intend to use it at work to help troubleshoot RF circuits (as it is capable of picking up WiFi, Bluetooth and LoRa signals). It's a cool little gadget, it sounds a little bit like a geiger counter, but it detects RF rather than radiation. I've thrown together an imgur album if you want to see what's in the guts of this thing. https://imgur.com/a/N5ia5xY All I did was replace some electrolytic caps. I would have liked to replace all of them, but I didn't have small enough caps on hand and I knew they wouldn't fit in the tighter spots. I will probably come back to it with some better parts (might even go with ceramics) in the future, but I just want to get it going (and get it off my workbench) for now. If I'm ever really bored I might reverse engineer the circuit and build a modern version using a PCB and surface mount parts. I expect it'll be about a quarter of the original size.
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Nov 30, 2019 08:45
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PDP-1 posted:you can get the boards made faster, like hours instead of weeks A bunch of services now can get you boards done and in your hands within 5 days for not-bad-at-all prices, so this is a lot less compelling nowadays. I still etch my own boards sometimes if I just need a little circuit or want to try out a design or something though, it's kinda fun (if messy and a pain in the rear end)
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Nov 30, 2019 17:53
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I'm looking to pick up a new pair of flush cutters since I keep breaking my cheap ones, is there a goon-recommended brand for higher quality ones? Also, any recommendations for automatic wire strippers? (the ones that have little jaws that grab each end)
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Dec 1, 2019 02:07
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Knipex, Swanstrom, Lindstrom, Wera, Wiha... Beware the prices. High end cutters can be $100+. I run mostly Hakko CHP cheapies, and I've never broken one. I've worn a couple out, but never broken one. What are you doing to break them? Just FYI, expensive ones won't handle abuse any better. I watched a coworker absolutely destroy $250 worth of Swanstrom cutters (2 pairs) by cutting steel stranded wire.
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Dec 1, 2019 02:41
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Also, with the auto wire strippers, I have issues with some kinds of solid core wire. It will cut the jacket, dig into the wire, and then the push the jacket back on the wire instead of removing the jacket on the part you're trying to strip.
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Dec 1, 2019 02:55
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taqueso posted:Arrow electronics has 29 RPI-029 (wifi) and 184 RPI-030 (no wifi) in stock but thats all I could find. those listings are someone reselling them for $40 and $30 respectively The closest I found was pihut allowing unlimited orders for the zero-w for $15 version with GPIO pins attached / $18 with an sd card. So goddamn annoying
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Dec 1, 2019 04:00
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moron izzard posted:those listings are someone reselling them for $40 and $30 respectively I didn't know until I went looking but it seems that the pricing and order limits are intentional due to the price being so low that there's virtually no profit margin for the Pi foundation: https://www.raspberrypi.org/forums/viewtopic.php?t=198705 quote:The profit margin on the Zero is so low that we can afford to sell it with a discount in one offs* to those people who really cannot afford the Pi3, but not in quantity to industrial buyers. They need to pay a price that makes it cost effective for us to sell. i.e. why should we give industrial users an educational discount...? https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=188011#p1184894 quote:Pi 0 and Pi 0 W are still under a one unit per customer sales limit due to high demand, and the need for production capacity to build other models.
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Dec 1, 2019 04:20
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moron izzard posted:those listings are someone reselling them for $40 and $30 respectively 200 bucks for 12 computers seems like a decent deal.
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Dec 1, 2019 04:32
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sharkytm posted:Knipex, Swanstrom, Lindstrom, Wera, Wiha... Beware the prices. High end cutters can be $100+. The ones I had were super cheap Chinese ones, I think one came with a 3D printer. The Knipex ones look decent for the price, I'll give those a go. Cojawfee posted:Also, with the auto wire strippers, I have issues with some kinds of solid core wire. It will cut the jacket, dig into the wire, and then the push the jacket back on the wire instead of removing the jacket on the part you're trying to strip. I have a plastic pair like this but cheaper and it fails like 10% of the time, but that's still 90% that I don't have to do manually! I was looking at the kinds with a jaw on both sides, think it would be an improvement?
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Dec 1, 2019 09:17
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Splode posted:So I mentioned it in a previous post, but I've finished* repairing the old radar gun detector I picked up from ebay. I intend to use it at work to help troubleshoot RF circuits (as it is capable of picking up WiFi, Bluetooth and LoRa signals). It's a cool little gadget, it sounds a little bit like a geiger counter, but it detects RF rather than radiation. That is really awesome!
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Dec 1, 2019 14:30
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VictualSquid posted:We had a pretty expensive one at my old workplace, mainly for RF circuits. But everybody avoided using it, mostly because of the terrible software. And it still broke pretty regularly. There are versions of these systems, which instead of a machine tool, use laser ablation to zap the copper off of the circuit boards. These work pretty well for patterning circuit boards for prototyping. They probably are too expensive for hobbyists though. silence_kit fucked around with this message at 14:58 on Dec 1, 2019 |
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Dec 1, 2019 14:53
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AgentCow007 posted:The ones I had were super cheap Chinese ones, I think one came with a 3D printer. The Knipex ones look decent for the price, I'll give those a go. I have a set of Knipex flush cuts that I picked up for $50. Worth literally every penny; they're the finest flush-cut pliers I've ever used. They're even actually rated for stainless steel safety wire up to .032"! Great for trimming nylon cable ties flush so they don't leave razor edges on your harnesses, too. For strippers, the Ideal Stripmaster is what the pros (and military) use. Replaceable blades for different types of wire. For reference, I am an avionics technician working on airplanes, and strip hundreds to thousands of wires a week
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Dec 1, 2019 15:57
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Anyone have any experiences with 3D printing circuit boards or is this still in its early stages where it's unobtainable by mere mortals?
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Dec 1, 2019 20:21
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Nobody's done anything workable that I've seen. Definitely work trying if you have any ideas
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Dec 1, 2019 20:34
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At this point, if you figure out something cool, you can probably patent it. I think I've seen 3-d printed 'wires' but not anything that implants the electronics bits into the plastic.
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Dec 1, 2019 21:01
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silence_kit posted:There are versions of these systems, which instead of a machine tool, use laser ablation to zap the copper off of the circuit boards. These work pretty well for patterning circuit boards for prototyping. They probably are too expensive for hobbyists though. Someone mentioned a while ago a hobbyist version of this where you paint a copper-clad board black, then use a laser to zap off the paint, then etch the board. No idea if that works well at all though. ante posted:Nobody's done anything workable that I've seen. Definitely work trying if you have any ideas The closest thing to "useful" I remember seeing was someone who 3D printed a plastic "board" with grooves in it, and then loaded solder into the 3D printer somehow and "printed" it into the grooves to make an incredibly ugly, blobby but technically functional circuit.
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Dec 1, 2019 22:16
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Home made PCB sounds fun as small project to see how things can be done, but it just seems like it's better to just get a professionally made board that will be better than anything you can do.
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Dec 1, 2019 23:05
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I have a closet full of old chemicals and I don't know what to do with it
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Dec 1, 2019 23:21
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It was a lot cooler when everything was through hole and fabs letting you buy 10 boards for $20/ea was laughable.
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Dec 1, 2019 23:25
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You can use the printer to mill a pcb like this https://www.youtube.com/watch?v=6ipcdhXetHY Though it seems like a pain in the rear end to get working properly (unlike regular 3d printing, right?), but it's possible. You could probably also use it as a plotter and draw with conductive ink. But really etching them chemically seems to be a much better solution if you want to DIY.
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Dec 1, 2019 23:50
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Troubleshooting on a budget questions: If I design a 2.4GHz antenna using a ceramic chip antenna, or a stamped metal antenna, or even an inverted-F PCB antenna, there is a pi filter on there usually, and often conflicting recommendations for values. Assuming the device cannot connect to WiFi, what are my options for tweaking the filter (I am assuming that that will be the issue)? I believe that if I have a VNA, I can plot out a Smith chart and tweak reactances to get it back into spec, but I have never done that in practice. Is there any strategy for troubleshooting, even throwing-poo poo-at-the-wall style of changing values and checking again, if I don't have a VNA? Similar, but different question: Say I have designed a MIPI CSI interface, using a few differential data lanes. If I plug it in and it doesn't work, how do I troubleshoot that? If the problem is in the signal integrity of the lines, I don't have a GHz-bandwidth scope, and even if I did, the impedance of the probes would gently caress that up anyway, no?
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Dec 2, 2019 00:13
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Shame Boy posted:
I've tried this but with homemade "solder paste" made of powdered graphite mixed with various glues, epoxies, and even acrylic paint. If you add enough graphite, the resistance is actually really low and you can paint circuits on paper and such. I applied the glue with a syringe and it hardened in the grooves. It worked but was messy as hell. What a dumb goose chase project that was. I'm one of the most beginner level people in this thread when it comes to electronics so I didn't want to invest in an etching kit, even a cheap probably garbage one just to play around but I do have access to a 3D printer. Nothing I would make would be complex at all. Here's the STL for a simple board for a Raspberry Pi weather station I made with it:  Right is for the Pi. Bottom left is for a BME280. Top left was for an ADC that was connected to a wind speed and direction board I also made that used reed switches. It was even more of a mess. Unperson_47 fucked around with this message at 07:44 on Dec 2, 2019 |
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Dec 2, 2019 00:38
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ante posted:Troubleshooting on a budget questions: I just find a reference design and follow it to the letter, as my work doesn't have a network analyser. If you had a signal analyser that would help a bit, but you're in scary RF territory now. The closest I've come was tuning an RFID loop I designed, but that's much lower frequency. All I did was measure the inductance with the very nice LCR meter at my work, then enter the inductance into the monster excel calculator provided by the manufacturer of the RFID chip. That spat out the values for the balancing network.
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Dec 2, 2019 07:41
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I think I fixed that I2C bus error  When it inevitably happened again I unplugged all the stuff from the I2C bus (since it's all off-board) and it still didn't recover, so I know nothing was holding the lines down and it had to be in software. Turns out it was the thing I was leaning towards, that the Microchip-supplied driver that sits on top of the base I2C layer has mutexes without any sort of timeout, so if anything happens that causes them to lock up it renders the entire bus inoperable even if you go in and reset it (which you can, because resetting it is done with a different mutex for some reason...). Anyway I didn't really need the features the driver was providing so I reimplemented a much simpler version with timeouts and checks and it's been running continuously for about 4 days now. Also I brought a few of my projects to thanksgiving to show my dad who's an EE but hasn't really done much hands-on stuff since everything was through-hole, and he was super fuckin' impressed by that GPS timing board y'all helped me design, called it a "work of art", so thanks thread 
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Dec 2, 2019 16:18
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Shame Boy posted:super fuckin' impressed by that GPS timing board y'all helped me design, called it a "work of art", so thanks thread 
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Dec 2, 2019 16:46
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Foxfire_ posted:For passing back "I ran" information to the idle task like I was talking about, you don't need to disable interrupts. Dragging this back up from a few pages ago, but I got around to implementing the flag system for the WDT and this post was real helpful in giving me a direction to check out. Apparently Microchip's compilers support C++11 but the libraries are only up to C++03 so there's no stdatomic.h, however the gcc builtins like __atomic_load and __atomic_store are there and translate into the correct MIPS LL/SC instructions, so I was able to do it with that. Thanks!
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Dec 3, 2019 16:12
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Anyway on to the interface for this thing: I'm trying to figure out how to drive some of those 16-segment common-cathode displays that also have decimal points (so 17 LED's total). The thing Adafruit uses is the HT16K33, which is nice and cheap and easily available on ebay, except it only has 16 segment outputs so I wouldn't be able to control the decimal point. The MAX6954 seems to do everything I want, except they're sixteen loving dollars each  Are there any better options?e: Actually wait it'd probably just be cheaper and easier to switch to common-anode ones and implement something with some more generic current-sinking LED controllers and some transistors controlled by a shift register on the anodes to multiplex, duh. Shame Boy fucked around with this message at 17:13 on Dec 4, 2019 |
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Dec 4, 2019 17:05
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