Difference between revisions of "Raspberry Pi"
From Christoph's Personal Wiki
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$ echo "0" > /sys/class/gpio/gpio27/value | $ echo "0" > /sys/class/gpio/gpio27/value | ||
$ exit | $ exit | ||
| + | </pre> | ||
| + | |||
| + | ===I2C=== | ||
| + | |||
| + | <pre> | ||
| + | $ sudo apt-get install -y python-smbus i2c-tools | ||
| + | </pre> | ||
| + | |||
| + | * If you know an I2C device is connected to your RPi, but you do not know its 7-bit I2C address, use the following command to find it: | ||
| + | <pre> | ||
| + | $ sudo i2cdetect -y 0 | ||
| + | </pre> | ||
| + | |||
| + | This will search <code>/dev/i2c-0</code> for all address, and if an MCP4725 DAC breakout is properly connected and it is set to its default address it should show up at <code>0x62</code>. | ||
| + | |||
| + | If you are using a 512MB Raspberry Pi version 2, you will need to use <code>/dev/i2c-1</code> by running: | ||
| + | <pre> | ||
| + | $ sudo i2cdetect -y 1 # as the i2c port number changed from #0 to #1 | ||
</pre> | </pre> | ||
Revision as of 03:16, 2 December 2019
This article will be all about my Raspberry Pi projects.
Contents
Miscellaneous
- Find Raspberry Pi IP address on your local WiFi network:
$ sudo nmap -sP 10.0.0.0/24 | awk '/^Nmap/{ip=$NF}/B8:27:EB/{print ip}'
#~OR~
IFACE=eth0
# trigger IPv6 neighbour discovery with link-local scope multicast:
ping6 -c2 -I $IFACE ff02::1 > /dev/null
# print the results, filtered by MAC address vendor prefix of Raspberry Pi Foundation:
ip -6 neigh | grep b8:27:eb
#~OR~
$ arp-scan --interface=eth0 --localnet | grep b8:27:eb
- Store the following in your
~/.ssh/configfile:
Host rpi
HostName 10.x.x.x
User pi
ProxyCommand none
TCPKeepAlive yes
ServerAliveInterval 5
PubkeyAuthentication no
PreferredAuthentications keyboard-interactive,password
Then,
$ ssh rpi
Or, better yet, use SSH keys.
- Find out where your Raspberry Pi was made and other details about the hardware:
$ cat /proc/cpuinfo | grep -E '^Hardware|^Revision|^Serial' Hardware : BCM2835 Revision : a22082 Serial : 0000000038e10351
Then, go here or here and, using the above hardware/revision codes, find out where you RPi was made.
So, in my case, I have a Raspberry Pi 3 Model B manufactured by Embest in 2016 (Q1).
32-bit or 64-bit
$ arch || uname -a armv7l # <- 32-bit => ARMv7 Processor rev 4 (v7l) armv8 # <- 64-bit => ARMv8 Processor
$ tr '\0' '\n' </proc/device-tree/model;arch Raspberry Pi 3 Model B Rev 1.2 armv7l
$ getconf LONG_BIT 32 # <- 32-bit 64 # <- 64-bit
$ dpkg --print-architecture armhf
Throttling
$ vcgencmd get_throttled
111100000000000001010 |||| ||||_ under-voltage |||| |||_ currently throttled |||| ||_ arm frequency capped |||| |_ soft temperature reached ||||_ under-voltage has occurred since last reboot |||_ throttling has occurred since last reboot ||_ arm frequency capped has occurred since last reboot |_ soft temperature reached since last reboot
Over-clocking
$ sudo cat /sys/devices/system/cpu/cpufreq/policy0/* 0 1 2 3 600000 1200000 600000 355000 0 1 2 3 600000 1200000 conservative ondemand userspace powersave performance schedutil 600000 BCM2835 CPUFreq ondemand 1200000 600000 <unsupported>
Useful commands
- Check which network the wireless adaptor is using:
$ iwconfig
- Print a list of the currently available wireless networks:
$ iwlist wlan0 scan
- Show details about the device's memory:
$ cat /proc/meminfo
- Show the size and number of partitions on the SD card or hard drive:
$ cat /proc/partitions
- Show which version of the Raspberry Pi you are using:
$ cat /proc/version
- Show all of the installed packages that are related to XXX:
$ dpkg --get-selections | grep XXX
- Show all of the installed packages:
$ dpkg --get-selections
- Show the IP address of the Raspberry Pi:
$ hostname -I
- List USB hardware connected to the Raspberry Pi:
$ lsusb
- Show the temperature of the CPU:
$ vcgencmd measure_temp
- Show the memory split between the CPU and GPU:
$ vcgencmd get_mem arm && vcgencmd get_mem gpu
- Display GPIO pinout (GUI-only):
$ pinout
GPIO
- Light up an LED:
$ sudo -i # Use GPIO pin 27 by creating a virtual file: $ echo "27" > /sys/class/gpio/export # Set pin 27 to ''out'' mode (allows us to turn on/off): $ echo "out" > /sys/class/gpio/gpio27/direction # Turn pin on/off: $ echo "1" > /sys/class/gpio/gpio27/value $ echo "0" > /sys/class/gpio/gpio27/value $ exit
I2C
$ sudo apt-get install -y python-smbus i2c-tools
- If you know an I2C device is connected to your RPi, but you do not know its 7-bit I2C address, use the following command to find it:
$ sudo i2cdetect -y 0
This will search /dev/i2c-0 for all address, and if an MCP4725 DAC breakout is properly connected and it is set to its default address it should show up at 0x62.
If you are using a 512MB Raspberry Pi version 2, you will need to use /dev/i2c-1 by running:
$ sudo i2cdetect -y 1 # as the i2c port number changed from #0 to #1
