61
votes
Is the Raspberry Pi vulnerable to the Spectre or Meltdown exploit?
According to ARM themselves, the processor cores used in all models before the Pi 4 are not vulnerable.
The majority of Arm processors are not impacted by any variation of this side-channel ...
- 6,158
59
votes
Virtual keyboard activation
First thing to do:
Open terminal
Second you will need to update the repositories:
sudo apt-get update
An upgrade to the whole system isn't needed but it is recommended:
sudo apt-get upgrade
Now ...
- 873
59
votes
Is it legal to use Raspberry Pi to develop a product and sell it?
The answer to the question if something is legal or not, depends on the interpretation of laws in a particular jurisdiction. This answer should not be treated as a legal advice. It is based on ...
- 4,224
37
votes
Accepted
What's the difference between the Raspberry Pi 1 Model B and B+?
Here's a list of the key differences (taken from my own blog at http://www.recantha.co.uk/blog/?p=10323)
4 USB ports – for the first time, you’ll be able to have a keyboard, mouse and wifi dongle ...
- 4,449
29
votes
Accepted
Does the Raspberry Pi need a cooling system?
I would like to add this image:
note that from the picture, the main component that gets hot is the USB/ethernet hub - by far, this MAY warrant a heatsink if you are using those components heavily, ...
- 1,281
29
votes
Accepted
Is it possible to add RAM to Raspberry Pi?
No. There is no method by which RAM can be added to the Pi. See this discussion on the raspberrypi.org forums for more details, but basically the RAM and CPU are inextricably, inaccessibly connected. ...
- 10.5k
28
votes
Accepted
What size screws does the Raspberry Pi board use?
tl;dr: Those models that have holes in the PCB are made for M2.5 (or UNC 3-48) screws and a length fitting to the enclosure or respective counterpart.
Pi 1 B+ contains four M2.5 mounting holes - ...
- 15.5k
26
votes
Accepted
Raspberry Pi Zero W is ARMv6 or ARMv7?
First: It's ARMv6.
The Zero uses the original BCM2835 SoC used on the first generation of Pi's and all the other single core models, with a ARM1176JZF-S processor (although the Zero models have ones ...
- 55.6k
25
votes
Accepted
Raspberry Pi hardware ID
Yes each board has a serial number. Methods to retrieve this are described here:
How do I get the serial number?
- 427
22
votes
What are the possible OUIs for the Ethernet MAC address?
The best resource to find the most current OUI assignments is from the MAC Address Block Large (MA-L) Public Listing at the IEEE -- http://standards.ieee.org/develop/regauth/oui/public.html.
A ...
- 321
22
votes
Is the Raspberry Pi vulnerable to the Spectre or Meltdown exploit?
The Pi (all versions) is not vulnerable.
Spectre and Meltdown both require out-of-order execution. The Cortex-A7 used in the early Pi 2 and the Cortex A53 used in the later Pi 2 and the Pi 3 is a ...
- 377
21
votes
Accepted
Why is the CPU sometimes referred to as BCM2708, sometimes BCM2835?
Actually the discrepancy is due to the designation of the silicon and the chip package. Originally there was the silicon die which is known as BCM2708, all initial development was done around this.
...
- 431
20
votes
Accepted
What are the RUN pin holes on Raspberry Pi 2?
Short answer: It is a reset.
Here is why:
From the ARM information center - Cortex-A7 MPCore Technical Reference Manual
Run mode
This is the normal mode of operation where all of the
...
- 2,503
19
votes
What is the maximum / minimum operational temperature?
It'll go way down to < -70°C according to the article: Raspberry Pi proven to be stable when submerged in liquid nitrogen.
UPDATE 29JUN2020:
The above link is nolonger working. A similar article ...
- 465
18
votes
Does the Raspberry Pi need a cooling system?
No, it does not need a cooling system. If the CPU gets too hot (>85C) it will throttle back the speed.
http://www.raspberrypi.org/forums/viewtopic.php?p=536478#p536478
Perhaps vendors sell heat-...
- 66.3k
17
votes
What components would I need for my Pi to safely detect a 12V automotive circuit on GPIO?
A very secure solution uses an optocouple. A 1kΩ resistor is good for an input voltage range of 5 to 20 volts. You may connect the two grounds, but it's not required.
The output is inverted, that ...
- 1,643
17
votes
Accepted
Raspberry PI 3B. Wifi and bluetooth shared antenna?
RPi 3B only has one antenna on board, so yes, it will be shared. Sharing is managed by the adapter firmware which is closed-source. Even if done right, it will not be as good as separate antennas.
...
- 26k
15
votes
Accepted
Can the Raspberry Pi power this 2.5" drive without a USB hub?
These type of enclosed hard drives conform to the USB specification 2.0 specification, even though it's USB 3.0 it must be able to fall-back. USB 3.0 provides lots more power, but since it falls back ...
- 17.1k
14
votes
What is the maximum / minimum operational temperature?
My experience with Raspberry Pi 3: The SoC will start to throttle down at approximately 80 degrees Celsius, and will, in my experience, never allow itself to be warmer than 85 degrees Celsius. This is ...
- 306
14
votes
How is a Raspberry Pi different from an old phone
If you have a phone that can run a full Open Source OS, with full access to the hardware, then perhaps you indeed have a better solution than what a Raspberry Pi can offer. Note that people have taken ...
- 4,993
13
votes
Accepted
What are the possible OUIs for the Ethernet MAC address?
To elaborate the answer from @cachius: the OUI has changed from
B8-27-EB (hex) Raspberry Pi Foundation
B827EB (base 16) Raspberry Pi Foundation
Mitchell Wood ...
- 39.5k
13
votes
Accepted
Should GPIO pins 13 and 14 be soldered together?
No they should not be soldered together (this is called a solder bridge). You should initiate a return request. You could cut or rework the trace yourself, but I would still suggest returning it - if ...
- 34k
13
votes
Accepted
Are there any damaging effects to leaving the Raspberry Pi on all the time
Provided you have no heat issues (check with /opt/vc/bin/vcgencmd measure_temp) you can leave your rPi running for all eternity. That's the beauty of the device paired with a well-written OS like ...
- 4,993
13
votes
Raspberry Pi Cluster Computer
You definitely cannot upgrade the ram. It is mounted to the CPU and is not user upgradeable like a desktop computer is. You can't physically swap out the CPU either, what you may be able to do is ...
- 34k
13
votes
Accepted
What can Raspberry Pi do that my Linux desktop can't
I have been told by some friends that Raspberry Pi computer is the "next best thing".
This is an ambiguous, unqualified, and subjective statement -- if my favourite thing is racing cars it ...
- 55.6k
13
votes
Accepted
Rpi freezes every now and then, how to fix it with a watchdog?
Before you go looking into additional hardware, please read up on what's called a "watchdog timer". The Raspberry Pi has a hardware watchdog built in that will power cycle it if the chip is not ...
- 1,161
12
votes
Control Hardware PWM frequency
According to this formula:
pwmFrequency in Hz = 19.2e6 Hz / pwmClock / pwmRange
We can set pwmClock=1920 and pwmRange=200 to get pwmFrequency=50Hz:
50 Hz = 19.2e6 Hz / 1920 / 200
I test it on ...
- 316
12
votes
Accepted
Detect if iphone/Android nearby?
Much hunting - learned quite a bit - no luck detecting other peoples devices without much of a low level wireless scan - Bluetooth works for iphone if both are your own devices:
Wifi scan might work ...
- 136
12
votes
Is it possible to add RAM to Raspberry Pi?
No.
Generally each Pi model has already been fitted with the maximum amount of RAM supported.
Some early model B's only had 256MB and could have had 512MB instead. However there would be no way to ...
- 66.3k
11
votes
Detect if iphone/Android nearby?
Me and some friends of mine have been developing a bluetooth-proximity scanner to open our front door lock of our hackerspace.
We've paired all allowed devices and essentially used hcitool to test if ...
- 583
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