moonshiness554/microcontrollers

Microcontrollers

##Topics Covered So Far:

We did cover many Linux Administration topics so far:

Command Line Editors:

• Nano
  • basic usage (WYSIWYG Editor by in large)
• Vim
  • basic editing and saving of files
  • switching between different modes (normal mode, insert mode, visual mode)
  • Macros for recording and automating code generation and tasks.
• Emacs* (will cover this on Wednesday)

Shell Scripting:

• Bash
  • piping outputs
  • redirection of outputs

#####League of its own: Python

• How to install pyserial and use it for communicating to the Arduino via the Command Line Interface.

#####CLI Utilities:

• crontab -e

  • min hour mday month wday Command
  • example: * * * * * open http://akk.li/pics/anne.jpg

• ls

  • lists the files, also can do ls -l for more information

• cd

  • changes your directory (aka which folder you are in).
    cd ~ moves to home folder, cd ~/Desktop moves to the desktop. cd .. moves back one folder

• pwd

  • prints to stdout your current location pwd
  • this will tell you where you are directory wise

• rm [filename] -deletes a file

• ps aux

  • actually ps is the command, but I always use it with ps aux so it lists all the current processes.
  • use this and grep to find a process, then get the id of the process and kill it with the kill command

• kill

  • example kill 82560 will kill (force quit) the program or process with id 82560

• grep

  • use this to search
  • I usually use this with pipes to narrow down on the key results:
    • ls -l | grep .sh will list all files that have an .sh in their name
    • ps aux | grep lovelySong.sh will only show the processes which have lovelySong.sh in their description.
    • history | grep ssh will look through all of your past lines and show any line with an "ssh" in it.

• ssh username@ipaddress

  • this command is a crowd pleaser, and it allows you to get into another computer. You all know very well what this means.

• ifconfig

  • lists information about the current internet connections. You may want to pipe the output to grep to quickly find the ip.

• arp -a

  • (*mac Only) lists the ip-addesses of those on your network

• open http://www.url.com

  • (*Mac Only) This command will open a specified url in a mac computer. There is a similar command xdg-open

• open [something]

  • It gets two lines because this command is really something. Open literally anything on a mac with this command.

• sudo shutdown -h now

  • This will allow you to shutdown a computer via the command line.
  • shutdown now is relatively universal -- I think the windows version is very similar.

• sudo shutdown -k now

  • This kicks other people off your computer.

• echo "hi there"

  • the "say" of the command line, really useful when you want your computer to talk to you

• read variableName

  • this allows you to store a value in some variable name. Really useful with echo.

• date

  • prints the date to the stdout.

• wall

  • writes everyone at the same time, interrupts their flow. (great for stun effect! -- but doesn't actually impede their typing if they know what they are doing)
  • e.g. echo "hello everyone" | wall

• write [username]

  • this starts talking to a certain user. It is more civil than wall.

#####Shell Loops:

• while [ 1 ] ; do echo date ; sleep 1; done
  • example of a basic loop in the command line.
  • when scripting in a .sh file it may look like this:

#!/bin/bash

while [ 1 ]
do
  echo date
  sleep 1 
done

#!/bin/bash
x=100
while [ $x -gt 0 ]
do
  say "Liftoff in $x seconds"
  sleep 1
  x=$(( $x - 1 ))
done

say -v "Just Kidding!  PsyKEE!"

chmod +x fileName

bash filename