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1500 questions
32
votes
11 answers
Copy existing Raspbian installation to smaller SD card
Is it possible to copy an existing and configured Raspbian installation to a smaller SD card?
When I first installed Raspbian I only had a 32 GB card at hand which obviously is bigger than needed.
mwld
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32
votes
5 answers
Why do the Pi GPIO pins use/give 3.3V and not 5V?
I know for a long time that people should NOT put more than 3.3V on the GPIO pins. They also give out 3.3V when high.
I did some research and it seems no one really bothered asking. Almost all of them talk about the maximum current.
If I am…
Aloha
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32
votes
3 answers
Can I use OpenCV?
While the Raspberry Pi is not exactly a powerhouse, it should be capable of doing some OpenCV image or video processing. Has anyone tried to install it?
Avogado
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32
votes
3 answers
How can I determine the current firmware version number?
Is there a way to find the current firmware version number? Either the running version or the version currently installed in /boot?
uname -a shows only the kernel version, not the GPU "binary blob."
Related: How do I update software and firmware?
finnw
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32
votes
6 answers
What is a typical boot time for the standard Debian distribution on a typical SD card?
How long does the RasPi take to boot when using the standard Debian distribution on a typical SD card? Are we talking less than a second? A couple of seconds? 10 seconds? 100 seconds?
This isn't too important for most users and applications, but…
winwaed
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32
votes
4 answers
How free is Raspberry Pi?
Is it legal to freely manufacture, distribute and modify Raspberry Pi?
Does Raspberry Pi have a license?
Are the hardware documentations and specs available to the public?
Are there any restrictions on the usage?
Adam Matan
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31
votes
1 answer
How can I detect that I'm compiling for Raspberry Pi?
As Raspberry Pi needs a bit of special code (I'm talking about C/C++) for accessing some hardware features (e.g. a call to bcm_host_init()). I'm looking for a reliable and elegant way to detect this automatically. I don't think there are any…
Tapio
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31
votes
2 answers
How does memory-mapped I/O addressing work?
How does memory-mapped I/O addressing work?
I'm trying to understand a sample supplied I2S: Anyone got it running?.
Configuring Clocks:
#define BCM2708_PERI_BASE 0x20000000
#define CLOCK_BASE (BCM2708_PERI_BASE + 0x101000) /*…
Dog Ears
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31
votes
5 answers
How do I create a new user?
Are there any security implications for creating (or not creating) a new user?
If need be, how do I create a new user or change the default user?
Andrew Fogg
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31
votes
3 answers
Raspberry Pi 3 audio input?
Did Raspberry Pi 3 add audio input? I'm new to RPi and interested in doing speech recognition but noticed input has been missing for previous versions.
If it hasn't, what is the best way for me to go about recognizing speech on RPi3? Thank you.
corysimmons
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31
votes
5 answers
Raspberry Pi with boots up with rainbow screen
How can I fix a Raspberry Pi with rainbow screen on boot up? I have good voltage coming in and I believe I've formatted and setup the SD card properly. I have two of these boards that do the same thing; I bought them months ago but I am only getting…
MEAM
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31
votes
3 answers
How to get Wi-Fi to connect on boot?
Raspberry Pi Model B
OS: Raspbian
I am running my Pi headless (currently through a direct Ethernet connection). I have a USB WiFi dongle. I would like to have the WiFi start up at boot and connect by…
katriel
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31
votes
3 answers
How can I use the GPIO pins as digital outputs?
I've read that the Raspberry Pi has a number of input and output pins.
How can I switch them? (from Python?)
What voltage logic?
Do I need pull-up or pull-down resistors?
Do I need to switch the pins from inputs to outputs?
Which pins are…
Alex L
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31
votes
14 answers
More powerful alternative to Raspberry Pi?
I already own a Raspberry Pi model B, and I am looking for a more powerful alternative. I want it to be able to run as a server (email, file, and web) and also as a media center. I know Raspberry Pi can do these things too, but I want something…
Christos Baziotis
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30
votes
6 answers
Choosing a Pi4 power supply
I'm trying to decide what is the best option for powering a Pi4. The specs mention for a minimum of 3A. Let's consider we would also like to connect a 2.5" drive to the Pi4. Could someone more experienced with power supplies help me with the…
m000
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