20191121/blink-8.c

-#include <avr/io.h>
-#include <avr/interrupt.h>
-#include <stdint.h>
-
-ISR (INT0_vect)  /* PD2 */
-{
-  PORTD ^= 0x40;
-}
-
-int main (void)
-{
-  cli ();
-  EICRA = 1 << ISC00 | 1 << ISC01;  /* INT0: steigende Flanke */
-  EIMSK = 1 << INT0;  /* INT0 einschalten */
-  sei ();
-  DDRD = 0xff;   /* binär: 1111 1111 */
-  PORTD = 0x40;  /* binär: 0100 0000 */
-  while (1);
-  return 0;
-}

20191121/hello-3.c

-extern int pruzzel (const char *__restrict __format, ...);
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}

20191121/hello-4.c

-int pruzzel (const char *bla)
-{
-  printf ("%s", bla);
-  return 42;
-}
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}

20191121/hello-5.c

-extern int pruzzel (const char *bla);
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}

20191121/hello-6.c

-#include "pruzzel.h"
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}

20191121/hp-uebung-20191121.tex

-% hp-uebung-20191121.pdf - Exercises on Low-Level Programming
-% Copyright (C) 2013, 2015, 2016, 2017, 2018, 2019  Peter Gerwinski
-%
-% This document is free software: you can redistribute it and/or
-% modify it either under the terms of the Creative Commons
-% Attribution-ShareAlike 3.0 License, or under the terms of the
-% GNU General Public License as published by the Free Software
-% Foundation, either version 3 of the License, or (at your option)
-% any later version.
-%
-% This document is distributed in the hope that it will be useful,
-% but WITHOUT ANY WARRANTY; without even the implied warranty of
-% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-% GNU General Public License for more details.
-%
-% You should have received a copy of the GNU General Public License
-% along with this document.  If not, see <http://www.gnu.org/licenses/>.
-%
-% You should have received a copy of the Creative Commons
-% Attribution-ShareAlike 3.0 Unported License along with this
-% document.  If not, see <http://creativecommons.org/licenses/>.
-
-% README: Zahlensysteme, Mikrocontroller
-
-\documentclass[a4paper]{article}
-
-\usepackage{pgscript}
-
-\begin{document}
-
-  \thispagestyle{empty}
-
-  \section*{Hardwarenahe Programmierung\\
-            Übungsaufgaben -- 21.\ November 2019}
-
-  Diese Übung enthält Punkteangaben wie in einer Klausur.
-  Um zu "`bestehen"', müssen Sie innerhalb von 70 Minuten
-  unter Verwendung ausschließlich zugelassener Hilfsmittel
-  14 Punkte (von insgesamt \totalpoints) erreichen.
-
-  \exercise{Zahlensysteme}
-
-  Wandeln Sie ohne Hilfsmittel
-
-  \begin{minipage}[t]{0.3\textwidth}
-    \begin{itemize}
-      \item
-        nach Dezimal:
-        \begin{itemize}
-          \item[(a)]
-            0010\,0000$_2$
-          \item[(b)]
-            42$_{16}$
-          \item[(c)]
-            17$_8$
-        \end{itemize}
-    \end{itemize}
-  \end{minipage}\hfill
-  \begin{minipage}[t]{0.3\textwidth}
-    \begin{itemize}
-      \item
-        nach Hexadezimal:
-        \begin{itemize}
-          \item[(d)]
-            0010\,0000$_2$
-          \item[(e)]
-            42$_{10}$
-          \item[(f)]
-            192.168.20.254$_{256}$
-        \end{itemize}
-    \end{itemize}
-  \end{minipage}\hfill
-  \begin{minipage}[t]{0.3\textwidth}
-    \begin{itemize}
-      \item
-        nach Binär:
-        \begin{itemize}
-          \item[(g)]
-            750$_8$
-          \item[(h)]
-            42$_{10}$
-          \item[(i)]
-            AFFE$_{16}$
-        \end{itemize}
-    \end{itemize}
-  \end{minipage}
-  
-  \medskip
-
-  Berechnen Sie ohne Hilfsmittel:
-  \begin{itemize}
-    \item[(j)]
-      750$_8$ \& 666$_8$
-    \item[(k)]
-      A380$_{16}$ + B747$_{16}$
-    \item[(l)]
-      AFFE$_{16} >> 1$
-  \end{itemize}
-
-  Die tiefgestellte Zahl steht für die Basis des Zahlensystems.
-  Jede Teilaufgabe zählt 1 Punkt. \addtocounter{points}{12}
-
-  (In der Klausur sind Hilfsmittel zugelassen,
-  daher ist dies \emph{keine\/} typische Klausuraufgabe.)
-
-  \exercise{Mikrocontroller}
-
-  \begin{minipage}[t]{10cm}
-    An die vier Ports eines ATmega16-Mikrocontrollers sind Leuchtdioden angeschlossen:
-    \begin{itemize}
-      \item
-        von links nach rechts an die Ports A, B, C und D,
-      \item
-        von oben nach unten an die Bits Nr.\ 0 bis 7.
-    \end{itemize}
-
-    Wir betrachten das folgende Programm (\gitfile{hp}{20191121}{aufgabe-2.c}):
-
-    \begin{lstlisting}[gobble=6]
-      #include <avr/io.h>
-
-      int main (void)
-      {
-        DDRA = 0xff;
-        DDRB = 0xff;
-        DDRC = 0xff;
-        DDRD = 0xff;
-        PORTA = 0x1f;
-        PORTB = 0x10;
-        PORTD = 0x10;
-        PORTC = 0xfc;
-        while (1);
-        return 0;
-      }
-    \end{lstlisting}
-  \end{minipage}\hfill
-  \begin{minipage}[t]{3cm}
-    \strut\\[-\baselineskip]
-    \includegraphics[width=3cm]{leds.jpg}
-  \end{minipage}
-
-  \vspace*{-3cm}
-
-  \strut\hfill
-  \begin{minipage}{11.8cm}
-    \begin{itemize}
-      \item[(a)]
-        Was bewirkt dieses Programm? \points{4}
-      \item[(b)]
-        Wozu dienen die ersten vier Zeilen des Hauptprogramms? \points{2}
-      \item[(c)]
-        Was würde stattdessen die Zeile \lstinline{DDRA, DDRB, DDRC, DDRD = 0xff;} bewirken?
-        \points{2}
-      \item[(d)]
-        Schreiben Sie das Programm so um,
-        daß die durch das Programm dargestellte Figur spiegelverkehrt erscheint. \points{3}
-      \item[(e)]
-        Wozu dient das \lstinline{while (1)}? \points{2}
-      \item
-        Alle Antworten bitte mit Begründung.
-    \end{itemize}
-  \end{minipage}
-
-  \begin{flushright}
-    \textit{Viel Erfolg!}
-  \end{flushright}
-
-  \makeatletter
-    \immediate\write\@mainaux{\string\gdef\string\totalpoints{\arabic{points}}}
-  \makeatother
-
-\end{document}

20191121/pruzzel-1.txt

-cassini/home/peter/bo/2019ws/hp/20191121> cat hello-5.c
-extern int pruzzel (const char *bla);
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}
-cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.c
-#include <stdio.h>
-
-int pruzzel (const char *bla)
-{
-  printf ("%s", bla);
-  return 42;
-}
-cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O pruzzel.c -o pruzzel
-/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
-(.text+0x20): undefined reference to `main'
-collect2: error: ld returned 1 exit status
-cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-5.c -o hello-5
-/tmp/ccfdwwB5.o: In function `main':
-hello-5.c:(.text+0xc): undefined reference to `pruzzel'
-collect2: error: ld returned 1 exit status
-cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-5.c pruzzel.c -o hello-5
-cassini/home/peter/bo/2019ws/hp/20191121> ./hello-5
-Hello, world!
-cassini/home/peter/bo/2019ws/hp/20191121>

20191121/pruzzel-2.txt

-cassini/home/peter/bo/2019ws/hp/20191121> cat hello-6.c
-#include "pruzzel.h"
-
-int main (void)
-{
-  pruzzel ("Hello, world!\n");
-  return 0;
-}
-cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-6.c pruzzel.c -o hello-6cassini/home/peter/bo/2019ws/hp/20191121> ./hello-
-cassini/home/peter/bo/2019ws/hp/20191121> ./hello-6
-Hello, world!
-cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.c
-#include <stdio.h>
-
-int pruzzel (const char *bla)
-{
-  printf ("%s", bla);
-  return 42;
-}
-cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.h
-extern int pruzzel (const char *bla);
-cassini/home/peter/bo/2019ws/hp/20191121>

20191121/pruzzel.c

-#include <stdio.h>
-
-int pruzzel (const char *bla)
-{
-  printf ("%s", bla);
-  return 42;
-}

20191121/pruzzel.h

-extern int pruzzel (const char *bla);

20191128/gtk-1.c

-#include <gtk/gtk.h>
-
-int main (int argc, char **argv)
-{
-  gtk_init (&argc, &argv);
-  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
-  gtk_window_set_title (GTK_WINDOW (window), "Hello");
-  gtk_widget_show (window);
-  gtk_main ();
-  return 0;
-}

20191128/gtk-2.c

-#include <gtk/gtk.h>
-
-int main (int argc, char **argv)
-{
-  gtk_init (&argc, &argv);
-  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
-  gtk_window_set_title (GTK_WINDOW (window), "Hello");
-  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
-  gtk_widget_show (window);
-  gtk_main ();
-  return 0;
-}

20191128/gtk-3.c

-#include <gtk/gtk.h>
-
-int main (int argc, char **argv)
-{
-  gtk_init (&argc, &argv);
-  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
-  gtk_window_set_title (GTK_WINDOW (window), "Hello");
-  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
-  GtkWidget *button = gtk_button_new_with_label ("Quit");
-  g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
-  gtk_container_add (GTK_CONTAINER (window), button);
-  gtk_widget_show (button);
-  gtk_widget_show (window);
-  gtk_main ();
-  return 0;
-}

20191128/gtk-4.c

-#include <gtk/gtk.h>
-
-int main (int argc, char **argv)
-{
-  gtk_init (&argc, &argv);
-  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
-  gtk_window_set_title (GTK_WINDOW (window), "Hello");
-  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
-
-  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
-  gtk_container_add (GTK_CONTAINER (window), vbox);
-
-  GtkWidget *button = gtk_button_new_with_label ("Quit");
-  g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
-
-  GtkWidget *drawing_area = gtk_drawing_area_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), drawing_area);
-
-  gtk_widget_show (drawing_area);
-  gtk_widget_show (button);
-  gtk_widget_show (vbox);
-  gtk_widget_show (window);
-  gtk_main ();
-  return 0;
-}

20191128/gtk-5.c

-#include <gtk/gtk.h>
-
-int main (int argc, char **argv)
-{
-  gtk_init (&argc, &argv);
-  GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
-  gtk_window_set_title (GTK_WINDOW (window), "Hello");
-  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
-
-  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
-  gtk_container_add (GTK_CONTAINER (window), vbox);
-
-  GtkWidget *button = gtk_button_new_with_label ("Quit");
-  g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
-
-  GtkWidget *drawing_area = gtk_drawing_area_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), drawing_area);
-  gtk_widget_set_size_request (drawing_area, 100, 100);
-
-  gtk_widget_show (drawing_area);
-  gtk_widget_show (button);
-  gtk_widget_show (vbox);
-  gtk_widget_show (window);
-  gtk_main ();
-  return 0;
-}

20191128/higher-math-2.c

-#include <stdio.h>
-
-#define VIER vier
-
-int main (void)
-{
-  printf ("Drei mal vier = %d.\n", 3 * VIER);
-  return 0;
-}

20191128/higher-math-3.c

-#include <stdio.h>
-
-#define VIER 4);
-
-int main (void)
-{
-  printf ("Drei mal vier = %d.\n", 3 * VIER
-  return 0;
-}

20191128/higher-math-4.c

-#include <stdio.h>
-
-#define VIER 4;
-
-int main (void)
-{
-  printf ("Drei mal vier = %d.\n", 3 * VIER);
-  return 0;
-}