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It says it needs 5V TTL to turn on the relay, which means the current coming out of your GPIO doesn't matter, it just needs to read 5 volts. And the relay they use says it only needs around 80 mA for 5V. Is there a way you can create 5V another way to test the relay? Or a meter to read the voltage coming out of the GPIO or whatever you're using to power the relay board?
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May 17, 2019 15:07
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It’s really hard to waterproof the Harbor Freight dummy camera enclosures. 
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May 17, 2019 16:43
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The Pi GPIO outputs are 3.3V only. The only 5V output is a fixed power rail that's split off from the USB 5V input to the Pi from its power supply. You likely will need a little level converter to bump the Pi GPIO up to 5V: https://www.sparkfun.com/products/12009
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May 17, 2019 18:25
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Cojawfee posted:It says it needs 5V TTL to turn on the relay, which means the current coming out of your GPIO doesn't matter, it just needs to read 5 volts. And the relay they use says it only needs around 80 mA for 5V. Is there a way you can create 5V another way to test the relay? Or a meter to read the voltage coming out of the GPIO or whatever you're using to power the relay board? Maybe I'm misunderstanding how voltage levels but I thought 5v TTL referred to this: https://learn.sparkfun.com/tutorials/logic-levels/ttl-logic-levels So it doesn't need to hit 5V on that pin, it just needs to reach the "high" mark. Regardless I did try using the second 5v pin on the pi to the channel and that didn't work either. I'm going to try a new power supply...
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May 17, 2019 23:54
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eddiewalker posted:It’s really hard to waterproof the Harbor Freight dummy camera enclosures. I have a handful of spare Pi Zeros and that's still painful to look at.
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May 18, 2019 01:00
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abigserve posted:Maybe I'm misunderstanding how voltage levels but I thought 5v TTL referred to this: https://learn.sparkfun.com/tutorials/logic-levels/ttl-logic-levels 3.3v outputs will often be able to drive 5v inputs due to the phenomenon in your link, yes, but it totally depends on how the 5v device is built. Some devices might interpret anything above 1v as a logic high, many will flip at around 2.5v, some might consider everything under 4v to be a logic low. The specific voltage required might also vary with the amount of current and the switching speed. Test it and find out, but the best solution is to use the level shifter.
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May 18, 2019 01:08
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Sagebrush posted:3.3v outputs will often be able to drive 5v inputs due to the phenomenon in your link, yes, but it totally depends on how the 5v device is built. Some devices might interpret anything above 1v as a logic high, many will flip at around 2.5v, some might consider everything under 4v to be a logic low. The specific voltage required might also vary with the amount of current and the switching speed. I am guessing there is no "standard" for this, so that wiki should probably elaborate a little more for the ranges? Edit: This elaborates more. https://electronics.stackexchange.com/questions/213051/how-do-i-use-a-5v-relay-with-a-3-3v-arduino-pro-mini Moey fucked around with this message at 01:18 on May 18, 2019 |
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May 18, 2019 01:15
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It sounds like the relay did do something when the GPIO went high. If the relay attempts to do something, that means the circuit got a logic 1 and attempted to switch it. If that is just a transistor, it gets a logic 1, which enables the transistor, which sends the VCC to the relay, which switches the relay. It could be that the VCC isn't high enough to switch the relay. The recommended current for the RPi is 2A, so I don't think it's your power supply unless it's not really putting out 2 amps. Could you try another power source for the VCC? Maybe try a few AA batteries. You can get 4.5 volts out of 3 of them.
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May 18, 2019 01:21
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A relay isn't using TTL signalling, you are actually powering a electromagnet coil that pulls the switch to the other position.
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May 18, 2019 01:26
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taqueso posted:A relay isn't using TTL signalling, you are actually powering a electromagnet coil that pulls the switch to the other position. If you look at the page for the board, it looks like it uses a transistor to send VCC to the relay. So the transistors are using the voltage from the GPIO to switch and then send the 5V to the relay.
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May 18, 2019 01:44
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I want to set my Pi up as a Airplay server, but don't want to plug my printer into the USB port, but have it added to the Pi via ethernet like it is for my laptops. Has anyone tried this? All the guides I see mention that it gets plugged in via USB.
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May 18, 2019 02:26
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Fyi CMOS logic high is about 3.5v, while TTL is more like 2v
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May 18, 2019 05:04
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So I replaced the power supply with an official RPI one (5.1v, 2.5 amps) AND I tried a different relay, still no good. Led lights up but the relay doesn't switch. I'll put a multi-metre on tomorrow but otherwise I'm stuck.
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May 18, 2019 08:18
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Well the mystery is solved; 1. the first relay I bought (https://www.iot-store.com.au/produc...e=OrderlyEmails) is actually a 12v relay, NOT 5V as it says in the picture and description, though it does say 12V in the name so this was my fault. 2. the second relay I got was right, but I misunderstood the labelling on the terminals for in and ground. All I had to do was swap them around and presto, it works. Thanks for the help guys!
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May 18, 2019 09:44
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Wish I'd looked earlier. If the electronic relays are the one I think they are, as long as they get 5v VCC, the 3.3v logic level from the RPi works fine. I have what could loosely be called a developer HAT, which I use an electronic relay to turn on and off the target board with a GPIO pin of the Pi I use to develop on. I've also had thousands of hours of operation out of electronic relays connected to an esp8266 which is 3.3v. Just be wary. They can get tired under higher current after a while.I ended up running two in parallel to handle a 90W load indefinitely. I was finding failures of a single relay randomly.
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May 20, 2019 11:50
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Will putting the PoE hat on a B+ add too much height to use a standard case (stock, without case spacers/risers I mean)?
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May 20, 2019 17:44
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That probably depends entirely on the case. It doesn't add much overall height but the screws for the fan in this picture do look like they poke up a little bit. You could probably take a drill to the case and make it fit but bear in mind it needs some holes to get air in for the fan as well.
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May 21, 2019 02:28
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Rexxed posted:That probably depends entirely on the case. It doesn't add much overall height but the screws for the fan in this picture do look like they poke up a little bit. Risers/spacers for the Cyntech cases are like 3 bucks, not a big deal. 
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May 21, 2019 02:33
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Are there any SBCs with storage more durable than the RPi microSD? Inevitably I end up having a 5-second power outage that corrupts the card and I have to reinstall the OS.
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May 25, 2019 20:05
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Malloc Voidstar posted:Are there any SBCs with storage more durable than the RPi microSD? Inevitably I end up having a 5-second power outage that corrupts the card and I have to reinstall the OS. Another option is to put your Pi on a battery pack.
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May 25, 2019 20:37
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Malloc Voidstar posted:Are there any SBCs with storage more durable than the RPi microSD? Inevitably I end up having a 5-second power outage that corrupts the card and I have to reinstall the OS. There’s a Korean one that’s MMC based, not sure if it’s good though?
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May 25, 2019 21:05
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MrPablo posted:Another option is to put your Pi on a battery pack. Just get an actual UPS. You can install monitoring software that will gracefully turn off the pi when you lose power.
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May 25, 2019 21:11
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I'm right now running my PC without UPS for the first time in like 15 years but the last one had an USB port to fastcharge phones and power other stuff (iirc it was 2.0A) and was perfect for a PI and even my old PSP.
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May 25, 2019 21:59
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Beaglebones have MMC so you can choose that or the SD to boot from. Or at lease the Beaglebone Green does, maybe others too
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May 25, 2019 22:00
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4GB should be enough  .E: Debian claims 2 GB disk footprint, PiHole claims 512, so that's a gig and a half of sweet sweet log data. Schadenboner fucked around with this message at 23:42 on May 25, 2019 |
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May 25, 2019 23:38
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DietPi
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May 26, 2019 00:10
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Ordered an Odroid-C2 plus eMMC module, I'll see if it ends up more reliable than a Pi.
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May 26, 2019 08:05
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MrPablo posted:Another option is to put your Pi on a battery pack. I have a Pi Zero with a Ps4 controller battery via the Elecrow pogo pin USB hub. Anyone trying that, the pins of the battery connector have to be reversed.
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May 26, 2019 12:04
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Malloc Voidstar posted:Ordered an Odroid-C2 plus eMMC module, I'll see if it ends up more reliable than a Pi.  I really hope you share more about them, they seem neat but the eMMC not being on the board  s me a little.E2: Where from, I understand the https://www.hardkernel.com site is official but the engrish and talk of bank transfers  s me slightly?E: ante posted:DietPi I like that they have a qualitative review of the boards inline with other units, I don't see a lot of brief synoptic reviews of SBCs super often, usually more like "I'm going to spend 20 pages reviewing this board, detailing each pin out" (maybe I just haven't been looking though)? Schadenboner fucked around with this message at 14:05 on May 26, 2019 |
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May 26, 2019 13:33
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Not quite the same, but I have an Orange Pi 3 with on board eMMC. Seems to be faster than the MicroSD but also way easier to corrupt. So I use the MicroSD.
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May 26, 2019 21:53
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Schadenboner posted:
I have an odroid c2 with the emmc module. It sticks pretty well to the board, still awkward though. I have never had it pop put on my during use. Odroid C2 with emmc is definitely faster than an raspberry pi with an SD card. It's night and day difference, but not exactly an apples to oranges comparison.
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May 26, 2019 23:08
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KKKLIP ART posted:I want to set my Pi up as a Airplay server, but don't want to plug my printer into the USB port, but have it added to the Pi via ethernet like it is for my laptops. Has anyone tried this? All the guides I see mention that it gets plugged in via USB. Hey, I did this by accident. I think you want AirPrint? I just installed cups and added the printer and then installed AirPrint. So my ol’ Brother laser printer is now AirPrint compatible and the pi is not connected to the printer via usb (just via network). https://www.geekonthepc.com/2016/07/10/guide-make-almost-any-printer-airprint-compatible-with-a-raspberry-pi-in-20-minutes/ Granted, I don’t remember doing all these steps - but maybe I did.
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May 26, 2019 23:29
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Schadenboner posted:
I ordered from ameriDroid; prices are slightly higher but overall it's cheaper due to shipping costs. Should be able to test it this week.
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May 27, 2019 01:09
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ohboy! My nVidia Jetson Nano arrived! I wasn't expecting it for a while so I have to write an image for it. To anyone jealous; I saved for it, and preordered it. I spend SFA on entertainment / hobbies really. Just being clear I'm not showing off. I got the shits because nothing I own could really do what I wanted to do any more. Plus proper OpenGL on an ARM based device is something I can use. It comes with a cardboard flat pack thing that is kind of like a cardboard drink holder. It sits in the box so there is a shallow depression where the nano sits. I think a case is going to be in its future. Usually I just buy a chap project box and hack it up so I can get to the holes. It looks even worse than it sounds. Something I didn't notice before is the documentation says that HDMI to DVI adapters don't work with it. That's a bit of a pain. The dev board is okay quality. Looks like they did a bit of an oldskool revision on it. There's a couple of SMC diodes or caps tacked in between a couple of USB solder pads and the USB chassis anchor points. USB-C is unpopulated. I guess they didn't fix the issue with this batch, so it has USB Micro instead. Yeah, I think I'll be using the barrel connector for power. It seems to have a PoE connector on it. What kind of sadistic bastard would use that?
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May 29, 2019 02:05
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MrPablo posted:That test should be CPU or memory bound, rather than IO bound. In other words, using an external hard drive shouldn't affect the run time by more than a second or so (particularly since the kernel will cache the files after the first run). I just tried this on a Jetson Nano with TensorFlow built for GPU. The results weren't great. I think it was because there seems to be a fairly large overhead in getting TF up and running on it. There was also an unpleasant surprise. Long story short, there was only a couple of hundred MB of RAM maximum to work with. I've now installed XFCE and have a good couple of GB to work with. Still oddly heavy, but much more free RAM than before.
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May 30, 2019 05:41
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edit: nm worked it out
hambeet fucked around with this message at 15:19 on Jun 6, 2019 |
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Jun 6, 2019 15:13
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General_Failure posted:ohboy! My nVidia Jetson Nano arrived! I wasn't expecting it for a while so I have to write an image for it. It having PoE makes a whole lot of sense since it has MIPI-CSI and onboard ML infra. General_Failure posted:I've now installed XFCE and have a good couple of GB to work with. Still oddly heavy, but much more free RAM than before.
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Jun 11, 2019 14:57
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evil_bunnY posted:It's a loving $100 piece of electronics, no sane person's gonna give you any poo poo over it. Also it can do 4k60 and has DP1.4 so even you end up not doing ML stuff it's a cool back-of-the-screen machine. 4GB. It's meant for running models, not training them.
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Jun 12, 2019 05:21
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Excuse my ignorance but is that nvidia jetson nano a raspberry pi on roids? Is what I get from reading its specs. Mt interest on that is purely for emulation purposes but then a Nvidia Shield TV for cheap is a nice one too...
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Jun 12, 2019 12:54
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MrPablo posted:4GB. Guillermus posted:Excuse my ignorance but is that nvidia jetson nano a raspberry pi on roids? Is what I get from reading its specs. Mt interest on that is purely for emulation purposes but then a Nvidia Shield TV for cheap is a nice one too...
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Jun 12, 2019 13:06
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