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Q: How long do I need to wait after a shutdown command before I can safely remove power? If you add the device tree overlay named gpio-poweroff to your /boot/config.txt file, the answer is simple: You need not wait at all. Some references for this answer: A forum discussion titled "How-To Create a GPIO Halt Signal", which went on for over two ...


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This is a reasonably straightforward implementation. However, I'd suggest your first step be to discard the article you've referenced - it's not quite correct overall. Also, because the semantics are confusing, I want to make this point very clear: You may shutdown the RPi when Mains power is out, but that is not the same as removing power from the RPi. The ...


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The documentation does not mention "short … to ground". It actually says "Initiates a shutdown when GPIO pin changes". You can use any logic circuit to pull the pin down. I think use of GPIO3 is problematic as it also states "After shutdown, the system can be powered up again by driving GPIO3 low" so you need to remove any ...


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As the power pins are connected to the same pad this is unlikely to be an issue. It is still a bad idea. I think you are overestimating the current your devices would require, but it is significantly higher than the Pi and would lead to voltage drop in the cables, unless you use infeasibly large cables. This probably won't worry the Arduinos but the Pi is ...


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Regarding PCB trace capacity, there is a lot of general information out there on the web. A calculator like https://www.mclpcb.com/blog/pcb-trace-width-vs-current-table/ may help you make an estimate. However, as the comments indicate, this is probably not a productive line of thought for your project. Reading up on the power requirements of each of your ...


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Though this is an old thread, I think I should add my direct experience. We run Pi cameras in remote locations, accessible only by backcountry airplanes or a multiday hike - Frank Church Wilderness. We have a few dozen of these out there and they have been running solidly 24/365.25. However, we have experienced perhaps 10 system failures that we have ...


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You can achieve what you want but not as you are suggesting. It does not matter if the fan is 5V 12V or 24V use a seperate power supply for it, do not power it with the Pi that is asking for destruction. Get yourself some MOSFETs or MOSFET modules that will turn on with 3V. The ones I use are opto coupled. With a MOSFET (N-Channel) connect the drain to the - ...


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You CAN power external components; indeed for some this is recommended. It is (generally) essential to share Gnd connections (opto-isolated devices are a possible exception). There is actually no need in this case, as the Pi 5V can easily supply the current needed by 2 relay coils. HOWEVER if you are using a relay module similar to that pictured they are ...


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Yes - you can definitely do that. Two things you must keep in mind: The RPi and the external battery-powered hardware must operate at a common reference potential. This is easily accomplished by connecting the two GROUND points together. RPi GPIO pins are biased at 3.3V, and they are rather fragile. You must properly interface them to your external ...


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Use this cable. It’s wired in parallel to provide 5 volts and can provide the full amperage needed. https://www.startech.com/en-us/cables/usb2hauby1 Startech part USB2HAUBY1


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Seeing as the Pico does not have a 5V output pin the answer is No. The VBUS pin will have whatever voltage you put on it, which may be 5V if powered by USB and this depends on what it is connected to. See https://raspberrypi.stackexchange.com/a/127865/8697 This will NOT control the fan and Pico GPIO pins are 3.3V low current.


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In general, yes this is possible. You must connect the grounds of both power supplies together at some point. You must also make sure that no 5 V logic signals that come from your 5 V logic are connected to pins on the Pi, as this can permanently damage the Pi. There is no danger of damage if GPIO outputs from the Pi are connected to logic inputs in the 5 V ...


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