Power is the ability to supply a device with energy. This question covers how to power the Pi, ways to do it, and the safe ranges of power.

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Is it possible to power a raspberry pi using android phone in USB host Mode?

the android phone can be used in USB host mode to power an arduino, pen drive,mouse. Is it possible to use the android phone to power a raspberry pi?
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21 views

Using Raspberry Pi to make Internet TV box (Power on/off issue)

I need to make a box (STB), which when plugged into TV can display live streaming URLs and can be controlled from remote control. So that a user can have the same experience as of a traditional live ...
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25 views

Pi not recognizing USB ports with an adequate PSU

So I got the Raspberry Pi B+ about 3 weeks ago and it hasn't been functioning 100% correctly... I have a PiHub to power my ehdd (1tb WD Elements), Wifi Adapter Realtek 8188CU, and (usually) the ...
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0answers
31 views

UPS for raspberry pi

I want to be able to power my pi like a smartphone (ie from battery or from mains (while charging the battery), hot swappable) I know there are boards like the MoPi that achieve this, but the ...
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1answer
32 views

Should I power my Pi and USB hub through the same power supply or separate ones?

Should I power my Pi and USB hub through the same power supply or separate ones? Because they both run. But which is better for the Pi?
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2answers
25 views

Unresponsive USB on a Raspi Model A

I've been running a headless Pi Model A (1 USB and no ethernet port) for a little while and it's just stopped working. The wifi dongle shows no life, and the pluggin keyboard has no effect. So I ...
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2answers
88 views

Reducing 24V to 5V for RPi PSU

I'm trying to power several devices off of a breadboard. For simplicity I want to power these all from the same PSU. The highest voltage amongst the devices is 24V. I was looking to use a 24V 2A ...
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0answers
18 views

No 'system halted' message when shutting down

I'm using putty to log into my pi through a serial console cable. I entered the command sudo shutdown -h now According to an answer to a previous question on shutting down the pi, I need to wait ...
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2answers
120 views

How to make Raspberry shutdown when I unplug the ethernet cable

I use my Raspberry Pi Model B with Raspbian as a server and I want to know (if it is possible) how to make that the Raspberry pi send itself a halt command when I unplug the Ethernet cable (eth0) Any ...
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1answer
75 views

UPS for Raspberry Pi and router (TPLINK TD-W8961)

I have started hosting a website on my raspberry pi, but because of the power outages, and mostly because I'm itching for a DIY project I would like to build a UPS for my pi and my router(12v-1,5A). ...
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0answers
120 views

Why I blew up my brand new B+

I blew my B+ up in less than 2 days.I want to know what went wrong to prevent it from happening again. What I remember doing: I was making GPIO to run for my RC car(1A motors), I did use TIP122 ...
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1answer
46 views

Why is pin 5 in the Ethernet connected to 3v3? is it safe to disconnect?

Looking at the pinout of the Pi's Ethernet, it looks like pin 5 is connected to the 3v3. Why is it connected there? According to the 100Base-T Ethernet specification, that should be unconnected. ...
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0answers
21 views

How much power can a Pi deliver to a SD card?

SD cards (the full-size ones) can use up to 330mW of power (100mA at 3.3V) - The Pi is known for having difficulty with certain high-speed (and thus high-power) cards, so I believe it is less than ...
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2answers
85 views

Powering a 24V 1A device

I've got a little project going where I want to hook up a load of sensors to my RPi (PH, Temp, Humidity, light etc. etc., a camera, and also power a 24v 1a DC device. I'm wondering if this is ...
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0answers
21 views

Wvdial and usb_modeswitch dont work unless Device is hotplugged

I want to connect to the internet using a 3g usb dongle. I have downloaded ppp, usb modeswitch and wvdial. Modeswitch is able to switch my from storage to modem only if I hotplug the device into the ...
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1answer
90 views

Power Pi from Li battery?

I would like to use a 4.2V(voltage varies from 3.6v up to 4.2v) Li battery to power a Pi - for this it seems like I would need a DC-DC boost converter. From what I found, all of those seem to create ...
2
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3answers
132 views

Pi Headless: How to confirm that the Pi is shut down

I am running my Pi headless connected to my wireless router using a ethernet cable. I wanted to shut down the pi remotely even when I am not connected to it using SSH/Putty to shut it down ...
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3answers
92 views

7.2V battery with Raspberry Pi

I want to use a 7.2V (4200mAh) battery with my raspberry pi but I need to convert the output to 5V (2000mAh), I tried the following formula: Ω = V / A but when I try to find the ohms the result ...
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2answers
63 views

power on from idle with gpio3, undocumented?

reading this thread : http://raspberrypi.stackexchange.com/a/19659/19456 i found out that you can power on the rpi from idle by connecting gpio3 (pin5 revB) to ground, tested it and it works great. ...
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2answers
74 views

Hot plugging the GPIO cable

I just got a raspberry Pi, and I am more familiar with software than hardware. Can I plug my ribbon cable into the GPIO pins if my Pi is on?
2
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1answer
304 views

Maximum current from usb (model b+)

I want to run the ps eye camera for my raspberry pi model b+. It is rated at 5v 500 mA . The question is , is it wise to directly connect it to the provided usb? I am using the pi to make something ...
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2answers
72 views

Raspi periodically unreachable via SSH

I'm using a RPi Model B as a file server back home. I set it up according to HTG's RPi file server guide, so I'm using SFTP to access the files on it. The RPi is wired to a Linksys router functioning ...
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2answers
107 views

What power supply should be used for the B+ model?

So I'm thinking about purchasing a RPi B+ model, and the Pi website states that the power supply should output 2A through a Micro USB supply. OK, but in terms of volts what should it be? Is 5V ...
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5answers
1k views

Why do people use powered usb hubs?

I have the RPi B+. It has four usb ports. At the moment I am powering an Arduino Mega, a small RFID reader and a keyboard. I plan to also power a wifi dongle and an arduino uno. Will this just work? ...
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2answers
58 views

Using a Generic Switching Power Supply

I have a generic 5V 10A switching power supply with screw terminals, that looks kind-of like this: Is it safe to use the output from here to drive the Pi by cutting a USB cable and connecting the ...
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2answers
59 views

Mult-head micro-usb cable

I am building a raspberry pi cluster. I am looking for a multi-head micro-usb power cable to power them. Does such a beast exist? Or can I make one myself?
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2answers
102 views

Is it fine to use an ASUS Memo Pad power supply on a B+ RPi?

I'm about to make my first RPi purchase (a B+) to be specific. I do not want to spend any more than I need to, and hence have looked around to see what power supplies I have that may already work with ...
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2answers
58 views

Raspberry unbootable after unexpected shutdown

I have a raspberry Pi, Model B. I installed Raspbian on the SD card and I would like to use it as a SVN server. I installed everything I need to work with it, and it works ok. The problem is that ...
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0answers
66 views

Powering 3.5 inch LCD screen and RPi with 7.4V Lithium Polymer Battery

I am attempting to create a portable Raspberry Pi. I am wondering how I would go about running the RPi and the LCD screen from the same battery. The screen draws about 6.5V. I have a 5V voltage ...
0
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0answers
30 views

Raspi not 'accepting' JUH340 USB Hub. (Raspbian OS)

Easily, not too many people have asked a question about this model of usb hub. What I'm attempting to use is a J5 CREATE JUH340 USB 3.0 with the RPi, but it is highly unworkable. With most everything ...
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1answer
68 views

How to use flash storage as blackout-proof volatile memory?

I plan on using the Raspbian derivative Industrial Perennial Environment or a similar solution to create a blackout-proof headless Raspberry Pi for use with various electronics. Obviously this means ...
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2answers
138 views

How long does the RPi last on a battery? [duplicate]

For how long can the Raspberry Pi run when powered from a battery of a given capacity? Of course this will strongly depend on how it is used and what devices are connected, but I am trying to get a ...
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0answers
40 views

Raspberry Pi is unstable on a single projector, appears to be HDMI related?

I have a Pi in our elevator suite that is intermittently not booting properly. While I look at the raspberry pi (powered by a TP-LINK POE splitter, we use them extensively for Pis) the red power ...
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1answer
49 views

Does the Raspberry Pi camera module have any power saving modes?

My question is related to this one I just asked But this time, I want to know if I can cut the camera power. A FAQ says it draws 250mA, but I don't always need it to be on, so are there any power ...
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0answers
72 views

how to cut power, especially by sleep mode and disabling peripherals?

I've never used the R. Pi before, but am considering it (model A) for my application. The main attraction is the hardware H.264 encoder, but not the power consumption :( I've read about a few power ...
0
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1answer
41 views

Does backfeeding the pi allow me to draw more current than normal from the other free usb port?

I've designed a PCB that does some I/O and powers the raspberry pi through one of the Pi's usb ports. I want to use the other free USB port for a wifi dongle. Since I'm backfeeding power will the ...
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2answers
152 views

Power external hard drive though USB — safe to use USB charger?

I would like to connect an external hard drive to the Raspberry Pi. This hard drive must be powered through USB and comes with a cable that has two ends (to ensure sufficient power). The cable is ...
2
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4answers
83 views

Powering an amp and a Pi from a single 12V lead?

I have a project in mind where I put a Pi into an old radio along a small amp (e.g.), or similar. The only problem is I'd like to only have one power lead to the whole thing. The amp takes a 12V ...
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2answers
134 views

Raspberry pi reboots when usb wifi (Edimax EW-7811UN) is plugged without usb extension cable

This is an odd issue that there have been quite a bit of discussion about even on this forum. Possible suggested issues range from insufficient power to bad internal hardware design of the pi. When ...
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0answers
42 views

Issue with hard drives, wifi

I had a set up with a powered external hard drive, and a wifi dongle. It worked fine. One day, the wifi dongle decided to cut out—it would restart every time I inserted it into the Pi, and after the ...
2
votes
2answers
87 views

How can I increase USB voltage on multiple Pi's?

I'm in a situation where I have to leave something like 10-12 Pi's for more than a week, and I want to connect independent HDDs to each one of them. It seems impossible for me to obtain individual ...
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1answer
54 views

Under what conditions is the system clock running?

The Raspberry Pi has no battery powered hardware clock, so it needs to fetch time via NTP and store it via fake-hwclock to not start at 1970 again after a power-loss. When the device is running the ...
0
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1answer
139 views

Disable HDMI Interface to achieve a lower power footprint

Is it possible, to turn off the HDMI video component? My Pi operates headless so there ist no need for me to have a video out component. If yes, how much power will be saved?
0
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1answer
83 views

Are there USB powered speakers with an Analog port?

I have built a raspberry Pi Jukebox, specially modified for a handicapped user (voice feedback on all songs, large buttons) but I have one.... last.... problem. The speakers I used ran off the analog ...
1
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1answer
235 views

Use GPIO to turn on external hard drive ONLY when needed

I have a Pi that is set-up with miniDlna for playing media to my tv and a samba server for a NAS set-up. My pi is connected to an external hard-drive that is actually just a hard drive enclosure; it ...
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1answer
51 views

Voltage controlled current amplifier [closed]

How to amplify current 1A, 5V from the 5mA, 5V??. More Particularly, In input side, i have 10mA and 5V and output side required 1A, 5V. Thanks.
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1answer
51 views

I want to switch power for a led strip

I'm making an on call sign that can be activated via a web page. I'm not sure if this is even necessary. but i was thinking about using a relay or some other device to power up the strip when in use ...
2
votes
1answer
63 views

Problems with the keyboarddddddd

I have recently gotten my raspberry pi and I have plugged in my wireless keyboard but am having difficulties typing. Just trying to log in, I get piiiiiiiiiiiiiiiiiiiiiiii when I just type pi. So I ...
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0answers
167 views

Multiple PIR Sensors

In my project I am using multiple PIR Sensors. I am providing power using the 5v pin number 2 and also using 3 Signal Pins for receiving. I noticed that if all three sensors are plugged in, then the ...
2
votes
1answer
79 views

Felt current on my Pi, could this have damaged it?

Here is what happened. I have a Belkin Surge Protector. I have connected my iPhone charger (5v 1A) to this and it powers my Pi. I have also connected powered USB hub, transcend hub3k to this surge ...