Difference: Quiz (2 vs. 3)

Mid - Semester Quiz

Embedded Systems course

General remarks:

In the following quiz more than one answer may be correct or all of the answers may be wrong.

Linux commands

1. You have downloaded the file yesterday.txt into your Downloads directory, which is a sub-directory of your home directory, as is the directory exercises.
   You want to copy this file into the exercises/solutions/exercise_2
   First you do:
   
   cd ~/exercises/solutions/exercise_3
   
   Which of the following commands will copy the file as desired?

• cp $HOME/Downloads/yesterday.txt ..

• cp ~/Downloads/yesterday.txt exercises/solutions/exercise_2

2. You are the super user and you do:

   cd /
   rm -rf
   
   This will:

• print “permission denied” and do nothing

• remove a file named ‘*’

• delete all files in the / directory except of directory files and their contents

3. You type:

   ls ~/Downloads > downloads.txt
   
   What will it print?

• All the file names in your Download directory

• nothing, but it will create an empty file named downloads.txt

• it will count the number of files you have in your Downloads directory

C programming

1. What does this function do?
   
   
   

• It calculates and returns the value of the sin function of an angle, which must be given radians (the angle parameter must be a double value in radians)

• It returns an error message

• It is simply plain wrong and does not compile

• It fails because the main program does not call the add function

• It fails because the main program should call the add function with the right variable names num1 and num2 and not val1 and val2

• If does not compile because the add function must be in a different file

The Raspberry Pi

1. What is gpio?

• a Generalized Peripheral Interface Option

• The Raspberry Pi does not have such a thing

• A university shuttle bus taking Uli to the I2C hostel

• An industry standard serial bus with only 3 connections:

  • Vcc

  • ground

  • a signal pin

• • Vcc

  • ground

  • a data line (SDA)

Understanding data sheets

Please read the attached data sheet and find out what the device does

• It is a device that is used to store non-volatile information in a micro-controller chip such as the ARM processor we use on the Raspberry Pi

• It is a memory type specially designed for embedded systems

• It is a memory type used within sensors