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Leandros posted:I've got a model B that I want to switch a relay which in turn activates a LED (all low frequency stuff). Now my original problem was that this relay requires a 5V signal and Vcc. So I bought a TTL level shifter (TI TSX0108e) and hooked it up, using +5, +3.3 and GND pins off of the Pi. The relay LED turns on but the relay doesn't click. I'm guessing the Pi can't provide enough juice. How can I properly connect the shifter? I've got an old PSU which can provide +5 and +3.3, but won't it be problematic if they're not referenced to the same ground as the Pi's signal? A while ago I set up a small circuit to drive a "light duty" (as opposed to heavy duty) relay using a transistor, resistor and diode. I can't find the exact diagram I used, but it was very similar to the first one here: http://www.susa.net/wordpress/2012/06/raspberry-pi-relay-using-gpio/ I think the diagram there has the exact same values as the diagram I used. It will allow you to power a small relay from the 5v pin on GPIO without drawing excessive current from the signal pin on the GPIO. It worked fine for my use.
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Feb 16, 2017 06:29
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What kind of relay is it? I don't have it handy right now but I use a 10A electronic relay I got from Aliexpress. I believe there is a 3.3v version somewhere but I have 5v ones. I found it can sort of work off 3.3v but switching can be a bit weak. However if the relay vcc is supplied with 5v and the trigger is 3.3v it works fine. I checked and there is no backflow through the trigger input. It needs very little current to trigger because of the type of relay it is. I was driving it from an esp8266 so it should work fine from a Pi. I actually bought a heap of those relays because 10A wasn't quite enough for the task. If I ever need the egg hatcher again I'll just wire a couple in parallel. Dirty but it'll do the job.
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Feb 16, 2017 08:20
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Paul MaudDib posted:I have a corner desk with a window on my left side. The short version is that yes you can make it work, however it will require a lot of tweaking of the timing and positioning of the led arrays to get it to work just right. And when the LEDs are out of sync or not properly located, the whole effect just looks ugly rather than soothing, so you may not consider it worthwhile to do. This true for both your current multiple monitor setup and the potential setup of a single ultrawide that extends past a window. The simpler thing to do is to just have a white-scale led array at a constant low output to put back there, which won't look bad but also won't give the full nice effect.
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Feb 16, 2017 15:32
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I decided to just buy another relay after finally finding a shop selling parts in town. Cost an arm and a leg compared to the Chinese webshops, but I don't mind paying extra for an actual shopfront every now and then
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Feb 16, 2017 21:33
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Leandros posted:I decided to just buy another relay after finally finding a shop selling parts in town. Cost an arm and a leg compared to the Chinese webshops, but I don't mind paying extra for an actual shopfront every now and then Yeah. Doesn't take a month or two to arrive either. Been flat out. Haven't dug out one of the relays yet. Speaking of postage... A long time ago I ordered a bluetooth 4.0 Dongle. It actually arrived today. Nothing else has. Shoved it in the OPi PC to test because the "real" PC is disconnected. Worked great first go with Armbian. tried it with my BT/whatever headphones from Target. I swear there was less screwing around than with the BT applet thing in Raspbian. That thing is so flaky and tends to screw up so badly the Pi needs a reboot. Set the DAC back up on my Pi3 last night. Somehow it worked because I was tired enough I couldn't see or think straight. I guess something broke in the overlays before during an upgrade.
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Feb 17, 2017 01:58
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I have found that most 5V relays work just fine with 3.3V. If you find a relay that triggers on low (ground) rather than high (3.3 or 5v) signal, you can drive control them through GPIO. I have used electromechanical relays on ESP8266 this way and they work just fine, and ESP8266 has even less juice on its GPIO pins (something like 12 mA max). If all you want to do is control a relay, an even easier way to do it is with one of these. With the USB relay you don't have to worry about frying GPIO pins or disconnecting the relay from the Pi (or PC or whatever). Driver software is available for Mac OS, Windows, and Linux. I haven't used the Windows software, so I don't know if it requires disabling driver signing or not.
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Feb 21, 2017 21:19
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PBCrunch posted:If all you want to do is control a relay, an even easier way to do it is with one of these. With the USB relay you don't have to worry about frying GPIO pins or disconnecting the relay from the Pi (or PC or whatever). Well that's cool, I never even thought to look for such a thing.
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Feb 21, 2017 21:29
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Thermopyle posted:Well that's cool, I never even thought to look for such a thing. I use a sainsmart 5V 4 relay one and its super easy. Found a python script to run it online.
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Feb 22, 2017 02:14
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I just unnecessarily went through hell trying to build Synergy so I didn't need to keep messing with shuffling keyboards and mice around. Got it to build on the PC in Ubuntu, and discovered that it's in the Raspbian repository. It's an older version but still works. No way in hell I'm going to pay $19 or $29 for GPL software that I'll barely ever use sorry. I was kind of disappointed that the one I built still wants a registration key. on the bright side I've found the stuff for activation in the source. Not needing to go through the disassembly and tracing stage is a welcome change for patching software activation, not that I've ever done it of course. It works very well by the way. Because I have dual monitors for the PC, and the Pi shares the right monitor with the PC I had to set it up so moving the mouse off the left of the left screen makes it appear on the Pi screen on the right. It's not as bad as it sounds. It'll mean way fewer mistakes typing on the wrong keyboard.
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Feb 22, 2017 07:19
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Thermopyle posted:Well that's cool, I never even thought to look for such a thing. If you want to go down the rabbit hole of cheap china relays, check out Sonoff wifi stuff on itead. eg: https://www.itead.cc/sonoff-wifi-wireless-switch.html Full ESP8266 with 10A relay, entirely re-programmable (have to solder som pins on) all for under $5 USD. 
John Capslocke fucked around with this message at 07:37 on Feb 22, 2017 |
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Feb 22, 2017 07:33
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Oh wow. They make them premade? Unlocked Synergy Pro. What? It's GPL! Still have to figure out if I can crosscompile it for armhf or if I have to do it onboard. Does anyone know? e: I built Synergy on the Pi3. When I packaged it lintian said that it made an armv61 deb. Am I overlooking something? When I tried some Orange Pi PC binaries (ARMv8 architecture) on the Pi 3 they worked fine. e again: That doesn't seem right Just ignore that. General_Failure fucked around with this message at 02:08 on Feb 23, 2017 |
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Feb 22, 2017 10:00
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PBCrunch posted:I haven't used the Windows software, so I don't know if it requires disabling driver signing or not. According to the blurb on that page, it uses the standard Windows HID driver, so that shouldn't be an issue.
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Feb 23, 2017 04:39
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AliExpress has cheap USB2.0 floppy drives. I purchased one to be used to back up what I can of my 1.44MB PC formatted floppies. I figure a Raspberry Pi is about the safest thing possible to use as a computer. Linux and ARM architecture guarantees no ancient horrors of virii(?) can wreak havoc. What got me is they have USB floppy drives, Floppy drive emulators with a standard floppy connector, but no floppy emulators with a USB connector. It might seem a little illogical for it to exist, but I don't think it is. Let's say I go through and make images of my floppies. My options are to mount them as a loop device in linux, or ??? for Windows. A USB floppy emulator can just have a USB stick with every single floppy image fitting easily on it which can be selected and mounted as a drive.
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Feb 24, 2017 00:17
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General_Failure posted:AliExpress has cheap USB2.0 floppy drives. I purchased one to be used to back up what I can of my 1.44MB PC formatted floppies. I figure a Raspberry Pi is about the safest thing possible to use as a computer. Linux and ARM architecture guarantees no ancient horrors of virii(?) can wreak havoc. Well ancient viruses generally don't work in modern Windows either (and for that matter, modern Windows malware generally can't run on Windows 9x and earlier). On Windows, you'd generally just extract the files from the disk image to a folder, as there's basically very little software that needs to be run from/with a floppy AND runs in Windows - there's plenty of DOS stuff that does, but you can't run that directly in Windows so it doesn't matter. You can of course mount disk images in DOSBOX or other virtual machines. Some programs that provide virtual optical disk drives can also mount virtual floppy drives, and there's also http://www.winimage.com/misc/filedisk64.htm which you can use with 64 bit Windows to mount floppy disk images as a drive. And that's before you consider that most things you want have no reason to be distributed as disk images when they can just be tossed in normal compressed files instead - disk images are necessary when you're dealing with different file systems, or things where the exact physical location of data mattered for copy protection purposes or other such functionality. With so many ways to get at the data from floppies, there's never really been a point to a USB floppy emulator - you can just read the disk images directly, any computer new enough to have USB is able to handle this task with ease. The whole reason we use floppy emulators on older systems is that they are not fast enough or capable enough to read directly from the floppies, especially when various anti-piracy checks are in effect.
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Feb 24, 2017 00:30
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fishmech posted:Well ancient viruses generally don't work in modern Windows either (and for that matter, modern Windows malware generally can't run on Windows 9x and earlier). A lot of old stuff was a headache for wanting absolute paths, even if the drive letter wasn't the important part. The smarter ones allowed the disk contents to be put in directories labelled DISCn for multi disc distributions. I've got a lot of old coverdiscs and various stubborn old software which like their paths to remain as-is. There are some old disks in the collection which I know had viruses. Some bootsector, some file. They need to be sanitised. What's stopped me doing this is I haven't had a PC with working floppy drive in a long time. About the only thing that can is a Mac G3 beige with System 9 on it, and I haven't set that up in years because I don't have much space. With potential viruses. There may be examples from the early 90's to 2003 or so. I know I have a 360k 5.25" with either California or Summer games on it somewhere with the Cookie virus on it. I kept it for the virus more than the software. Can't even remember where I got that disk. You know what. I totally forgot that DOSBOX existed. Of course that mounts images. Speaking of copy protection. Lemmings had a bastard of a copy protect. A small hole in the disc made with a laser in a specific spot. I've got a slightly different question I want to ask. Are there any low priced yet interesting ARM based SBCs around right now? I've been tempted by the Orange Pi PC 2 http://www.orangepi.org/orangepipc2/ because of the H5 SoC and to be honest the completely mental component placement. But it doesn't really stand out. The Orange Pi 2 somethingorother is interesting because it has 2GB RAM, but it just has an H3 like the Orange Pi PC. So "meh". I was going to grab a C.H.I.P. mostly for PICO8 but I can't really see the hardware doing anything interesting that a Raspberry Pi can't.
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Feb 24, 2017 02:18
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General_Failure posted:A lot of old stuff was a headache for wanting absolute paths, even if the drive letter wasn't the important part. The smarter ones allowed the disk contents to be put in directories labelled DISCn for multi disc distributions. Sure, but nearly all of those things require true DOS to function right, so you're either running it on DOS itself, which can't handle generic USB devices easily (unless someone has specifically written DOS drivers for it), you're running it in Windows 3.1 which again lacks native USB support, or you're running it in Win 9x which has USB support. But for all of those, you're almost certainly running it on a system with a floppy disk controller onboard and you can have the floppy disk emulator connected that way, or you're running in a virtual machine which can mount it. So there's really no point to making a modified floppy drive emulator which connects via USB. And a lot of the rest is 16 bit Windows applications which also can't run in modern 64 bit Windows. The vast majority of Windows software expects to be installed to the hard drive rather than running from floppy, and usually has nice little config files you can mess with if it tries to do its installs directly from A:
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Feb 24, 2017 02:34
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fishmech posted:Sure, but nearly all of those things require true DOS to function right, so you're either running it on DOS itself, which can't handle generic USB devices easily (unless someone has specifically written DOS drivers for it), you're running it in Windows 3.1 which again lacks native USB support, or you're running it in Win 9x which has USB support. But for all of those, you're almost certainly running it on a system with a floppy disk controller onboard and you can have the floppy disk emulator connected that way, or you're running in a virtual machine which can mount it. So there's really no point to making a modified floppy drive emulator which connects via USB. And a lot of the rest is 16 bit Windows applications which also can't run in modern 64 bit Windows. Well... poo poo. You make an excellent point. Never mind then!
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Feb 24, 2017 04:56
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Really looking forward to getting a Pi to mess with for DIY stuff. Gonna look into gaming and media-box-related projects firstly.
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Feb 24, 2017 05:32
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Spacedad posted:Really looking forward to getting a Pi to mess with for DIY stuff. Gonna look into gaming and media-box-related projects firstly. They are reasonably good at that for the price, if you want the satisfaction of DIY too, or something a bit more custom than what's available. I don't know what your background or intent is, but some things are done way better with Arduino. Great for slap together jobs. Adding the esp8266 support to Arduino also allows for other things including IoT support. If you need things with fine grained response time and relatively easy setup, go Arduino and interface it to the RPi. Take my word for it, a Raspberry Pi can't do realtime IO response under any realistic conditions. I wrote an IO library for RISC OS which even running in single task mode still had some pretty regular and large hiccups. It was accessing the registers directly. I do think the Raspberry Pi and other loosely inspired SBCs are pretty interesting and useful. Having access to IO pins is really nice. Computers are DIY friendly again! Only took what... 20 to 25 years?
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Feb 24, 2017 09:01
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Does anyone have suggestions on cheap small displays that take composite input and aren't using those terrible 480x234 displays that result in the output being blurred to unusuability? For the project I'm considering with an old Raspberry Pi, it wouldn't need to do more than normal NTSC resolution and I figure going with the composite output should result in a cheaper device than using the HDMI output. I'm looking to spend $60 or less all in with shipping.
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Feb 24, 2017 23:44
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Honestly in 2017 I doubt a composite-capable display will be cheaper than a HDMI one. Decoding the analog composite signal and converting it to a digital signal to drive the LCD takes extra work and chips that aren't worth including in modern displays.
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Feb 25, 2017 00:22
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fishmech posted:Does anyone have suggestions on cheap small displays that take composite input and aren't using those terrible 480x234 displays that result in the output being blurred to unusuability? For the project I'm considering with an old Raspberry Pi, it wouldn't need to do more than normal NTSC resolution and I figure going with the composite output should result in a cheaper device than using the HDMI output. I'm looking to spend $60 or less all in with shipping. You need to check the specs but sometimes digging around on AliExpress or eBay for reversing camera screens yields higher res LCDs with composite in. I'm sure you're well aware though that composite on an LCD looks like utter garbage no matter the size. What size range are you thinking anyway? I have no idea if this link works just copypasted. It's one I added to my AliExpress wishlist a couple of months back when it was reduced but forgot about it. I can't speak for how good it actually is, but the description says it's 800x480 I included the description in case the link is bunk. 4.3 inch TFT Color LCD Screen Car Reverse Rearview Display support Auto Rear View Backup Camera Parking System Monitor http://s.aliexpress.com/jMRjuM7F
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Feb 25, 2017 00:24
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General_Failure posted:4.3 inch TFT Color LCD Screen Car Reverse Rearview Display support Auto Rear View Backup Camera Parking System Monitor I have one of those, it's surprisingly good all things considered. If you can keep the output of your source B/W by nature of the thing you get a sharper picture, but don't get too high hopes with tiny console fronts. I have been using it as a testing screen for old computers, like A500s etc.. You can also open up that particular screen and throw out the voltage regulator and then bridge it, that way you can feed it with +5V from an USB source.
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Feb 25, 2017 00:30
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General_Failure posted:You need to check the specs but sometimes digging around on AliExpress or eBay for reversing camera screens yields higher res LCDs with composite in. I'm sure you're well aware though that composite on an LCD looks like utter garbage no matter the size. What size range are you thinking anyway? Looking for around 7-11 inches ideally. And looking kinda crappy would be part of the point, for emulating early 80s computer systems with. None of the ones I'm looking at actually output more than 256x192 resolution, but the 480x234 screens that are so common tend to have extra scaling issues. I mean, if there's some acceptable HDMI models for similar prices that'd be ok too, but it's looking like the "rear view" search tip really helps.
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Feb 25, 2017 00:43
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If it's for retro stuff check out Goodwill and thrift stores. Pick up an old 4:3 aspect ratio LCD monitor. The early ones took VGA and you can get HDMI or composite to VGA converters. Or if you get a DVI display it's easy to convert HDMI to it too. That's your best bet IMHO--I picked up a nice 19" Dell LCD for $5 for example.
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Feb 25, 2017 00:46
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If size is not an issue (which I suppose it kinda is) an old CRT TV is also a good bet. They're still plentiful around here on eBay in that price range. In smaller there are portable TV sets with ~11" screens that usually need external 12V power sources, these work too. They do not always come with a composite connector though, that would have to be checked first.
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Feb 25, 2017 00:59
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I've got a Python script running that takes pictures and uploads them to Dropbox. If the internet is down, it saves file names to a text file to be uploaded later. I've also set it up so that if the power goes out, the script will relaunch itself on power up. Is there anything else I should be considering for this project or in general with power outages?
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Feb 27, 2017 11:49
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Watch the free space. Watch overwrites.
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Feb 27, 2017 12:04
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evil_bunnY posted:Watch the free space. Watch overwrites. I've added two functions, one that purges images over X days old and another that names each file uniquely depending on the time.
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Feb 27, 2017 12:19
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General_Failure posted:What got me is they have USB floppy drives, Floppy drive emulators with a standard floppy connector Those floppy drive emulators w/40-pin floppy connectors are generally used for synths/sequencers/samplers/other music-production and industrial equipment that have a floppy drive but are horrendously expensive to replace the whole unit.
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Feb 27, 2017 14:29
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A new Raspberry Pi variant for sale, that you won't be able to buy for the advertised price, if you can find it in stock. Wireless version of the Pi Zero, the Pi Zero W https://betanews.com/2017/02/28/raspberry-pi-zero-w-is-a-10-computer-with-wi-fi-and-bluetooth/ "Priced at $10, the Pi Zero W uses the same Cypress CYW43438 wireless chip as Raspberry Pi 3 Model B to deliver 802.11n wireless LAN and Bluetooth 4.0 connectivity." I wish they would swap the Micro-USB On-The-Go port for USB-C or just a regular USB port. Not that it matters, they'll sell out instantly and you won't be able to buy one for over a year
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Feb 28, 2017 18:13
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This means that the old Pi Zero will finally be available at a reasonable price, so that's ok news.
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Feb 28, 2017 19:31
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Hadlock posted:I wish they would swap the Micro-USB On-The-Go port for USB-C or just a regular USB port. Not that it matters, they'll sell out instantly and you won't be able to buy one for over a year I like the OTG port. My current zero is running with the OTG port acting like a network adapter so I can easily connect to it from my PC. Obviously that use doesn't really apply to the 0W, but since it can also be used to emulate an input device, a disk drive, etc. there's a lot of fun to be had with that. I'd be fine with a type C since that can retain OTG functionality, but definitely not a type A.
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Feb 28, 2017 20:15
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Argh, ok, so I bought another 4-relay board that works straight from the Pi's 3v3 rail. It works fine, but I want to use it to drive a bipolar stepper motor with the following circuit: I've got the script working, but whenever I hook up the stepper as well as the power source, a 12V flatbed scanner transformer which can deliver 1250mA, the entire Pi just shits itself and reboots. When setting up the pins as output, all relays flip on and it's fine, but as soon as it gets to the inverting of currents, the Pi dies. I'm guessing it has something to do with the residual energy in the coils, as a demo I made with some LEDs works fine. I tried to put some diodes between the +3v3 and GND wires (right now everything is hooked up directly) before reaching the relay board but that lowered the operating voltage too much and didn't let the relays flip. I also added another single relay to switch off the +12V between changing the stepper motor, and even that crashed it. Any ideas? Leandros fucked around with this message at 19:34 on Mar 1, 2017 |
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Mar 1, 2017 19:31
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Hadlock posted:A new Raspberry Pi variant for sale, that you won't be able to buy for the advertised price, if you can find it in stock. Wireless version of the Pi Zero, the Pi Zero W
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Mar 1, 2017 21:02
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This is driving me nuts. My Raspberry Pi 2 won't bring up my wlan0 on boot. However, when I unplug my wifi USB dongle and replug it back in, then it works instantly. This behaviour is with 2 different brand of dongle. What am I doing wrong? Here is my /etc/network/interfaces:code:
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Mar 3, 2017 10:11
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Should that second manual not be dhcp? Or are you setting statically Also check its actually bring picked up as wlan0 on boot and not wlan1 for some reason
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Mar 3, 2017 15:54
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Recently I ordered two Raspberry Pi 3s a few days apart from the same Amazon link. One arrived in a secure, official-looking box, while the other was shipped loose in an anti-static bag housed in a bubble wrap mailer. The one that came in the bubble wrap is missing a GPIO pin.  It hasn't been sheared or bent off or appear to have been damaged in shipping. It looks like it was never there at all, kind of like what happened to the guy at this link. I was never planning to use the GPIO pins on either of these boards, but I'd like to know if it's safe to use this one at all. Like, is it going to short out or burn anything down if I plan to use it as a 24/7 pihole/vpn box? FWIW, if I'm reading this layout right, it's pin #38 GPIO20.
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Mar 3, 2017 19:37
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I'd return it on principle.
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Mar 3, 2017 19:47
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Judge Ito Boxing posted:Recently I ordered two Raspberry Pi 3s a few days apart from the same Amazon link. One arrived in a secure, official-looking box, while the other was shipped loose in an anti-static bag housed in a bubble wrap mailer. If you ever handle those 0.1" headers like that (before they are fixed to a board), the pins can slide in and out of the plastic brace with a little bit of force, so its not completely unheard of for one to come loose.
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Mar 3, 2017 21:20
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