61
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 speculation mechanism. A definitive list of the small subset of Arm-designed processors that are susceptible can be found below. [see link for the table]
The ...
59
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 we can install the virtual keyboard:
sudo apt-get install matchbox-keyboard
Rebooting is recommended:
sudo reboot
Now you can access the keyboard:
Menu >>...
58
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 published information by the relevant party.
Raspberry Pi Foundation made a clear statement that answers your question in the Starting a business with a Raspberry Pi ...
36
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 plugged in without needing a powered hub. Bear in mind, you will probably need a more powerful power supply for the B+ if you want to use all 4 ports. They’re ...
29
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, it has restricted airflow due to a case/etc. and it is in a warmer environment, or some combination thereof.
The second component that gets warm in the image is ...
29
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. There is no physical method by which RAM could usefully be added, unless you want to start acid stripping the CPU chip, getting your microscope out and tracking ...
28
I've recently had some reason to start experimenting with PWM myself, and found that (as pointed out by one of the comments) the frequency seems to vary with duty cycle - bizzare, right? It turns out that Broadcom implemented "balanced" PWM in order to make the on and off PWM pulses as evenly distributed as possible. They give a description of the ...
26
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 - supposedly drilled to 2.75 +/- 0.05 mm. This information is taken from the "Raspberry Pi B+ Mechanical Schematic" (official drawing by J. Adams, 07/03/...
25
Yes each board has a serial number. Methods to retrieve this are described here:
How do I get the serial number?
25
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 binned as 1000 Mhz instead of 700).
All ARM11 cores use the ARMv6 instruction set architecture. Since those using ARMv7 or 8 are backward compatible with ARMv6, ...
22
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 complete list of OUI assignments is compiled daily and is available at http://standards-oui.ieee.org/oui.txt.
According to this list there is a single OUI/MA-L ...
22
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 strictly in-order architecture. The ARM11 used in the Pi 1 is partially out-of-order, but not in a way that permits Spectre or Meltdown to work.
ARM confirms ...
21
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.
In a stacked 9x9 package with 256MB of DRAM it is then known as BCM2763. (Stacked is when you literally bond the DRAM silicon on top of the processor and put ...
20
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
processor functionality is available. The Cortex-A7 MPCore processor
uses gated clocks and gates to disable inputs to unused functional
blocks. Only the logic ...
19
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 can be found
here.
18
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-sinks to gullible people for the same reason they sell gold plated digital audio cables, they make a profit.
There are tests videos on YouTube. Here is one with ...
17
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 means, the Pi senses low on its GPIO if there is 5–20V on the input, and high if not.
simulate this circuit – Schematic created using CircuitLab
17
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.
You can get a USB dongle for either WiFi or BT (and use that instead of the built-in adapter) to get two separate antennas.
15
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 it must conform to the USB 2.0 500 mA maximum current. The hard drive itself might use more power, but the built-in electronics will detect when to use ...
14
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 the processor from modern phones and turned it into a Raspberry-like board already (See the Odroid board at www.hardkernel.com). However, most phones do not ...
13
Another option would be to use a port expander to get additional I/O ports.
For example, the MCP23008 can connect via I²C (only uses two pins) and gives you eight I/O ports.
Since it uses I²C, up to eight of them can be connected to the same two I²C pins to give you up to 64 I/O pins.
Adafruit has a tutorial about how to use the MCP23008 (or MCP23016, the ...
13
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 House
Caldecote Cambridgeshire CB23 7NU
UNITED KINGDOM
to
DC-A6-32 (hex) Raspberry Pi Trading Ltd
...
13
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 you have problems down the road you may not be able to successfully return it if you cut the bridge yourself..
13
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 raspbian which does not (or hardly) suffer from memory leaks etc.
13
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 overclock the CPU but that may already have been done. You can set the clock speed using the following command:
sudo raspi-config.
As for clustering, the program ...
13
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 is very unlikely I would consider the Raspberry Pi "the next best thing", etc.
So to be meaningful and usefully evaluated, we need to consider some ...
12
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 of course the core temperature - the temperature outside the chip will have to be much lower to facilitate efficient heat exchange.
While you (probably, don't ...
12
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 alarmpi:
$ pacman -S wiringpi
$ gpio mode 1 pwm
$ gpio pwm-ms
$ gpio pwmc 1920
$ gpio pwmr 200 # 0.1 ms per unit
$ gpio pwm 1 15 # 1.5 ms (0º)
$ gpio pwm 1 ...
12
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 for some devices, but iOS ones do not connect when screen is off! My iphone 6 could be detected with simple arp command (gives table of ip and mac numbers of ...
12
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 update the RAM chip without destroying the board (unless you had a special laboratory).
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