Implement and document Arduino software

.gitignore

@@ -0,0 +1,2 @@
+/documentation/build/
+/source/arduino/build/

README.md

@@ -21,24 +21,126 @@ includes a field indicating whether the space is open or closed.
 
 ## Arduino
 
-## Python Script
+### Arduino: Hardware
+
+We measure the door's lock state using a reed switch. The switch is installed at
+the bottom of hole for the deadbolt and gets triggered by a magnet glued to the
+tip of the deadbolt.
+
+The reed switch is connected to pin 0 and ground on an Arduino MKR1000. The
+software sets up pin 0 (by default) with a pull up resistor. This prevents
+currents induced into the long wire between switch an Arduino to trigger the pin
+state.
+
+A second component connected to the MKR1000 is an Arduino MKR RGB Shield that
+provides a 7x12 RGB LED matrix. It is used to give visual feedback on the
+software's current state.
+
+While trying to connect to the configured WLAN, a vertical yellow line
+oscillates between both sides of the display. When connecting to the WLAN fails,
+a red cross is displayed. When the room is open all LEDs are green, and when it
+is closed all LEDs are turned off (nobody should be there to see it anyway).
+
+The following images is a schematic showing the connections between the three
+components mentioned.
+
+![a schematic of Arduino MKR1000 and all components physically connected to it, as described in the text](documentation/arduino.png)
+
+The Arduino is powered by a USB charger.
+
+If you need to change the schematic, adapt `documentation/arduino.tex` and run
+`make`. This requires the following software and TeX libraries to be installed
+on your systems:
+
+- pdflatex
+- convert from ImageMagick
+- tikz
+- circuitikz
+
+### Arduino: Setup and Configuration
+
+The sketch for our Arduino is located in `sources/arduino`. Before we flash the
+Arduino with the sketch, we should adapt `config.h`. We can use either the
+[Arduino IDE](https://www.arduino.cc/en/software) or the provided Makefile to
+verify or flash the sketch.
+
+For the Makefile to work,
+[Arduino CLI](https://arduino.github.io/arduino-cli/latest/) has to be
+installed. Use `make` for verification and `make install` to flash the board,
+which needs to be connected to our PC via USB cable.
+
+Verifying and flashing the sketch requires the installation of several
+libraries.
+
+First we need the core for the family of boards Arduino MKR1000
+belongs to: Arduino SAMD Boards (or `arduino:samd`). Installation instructions
+for [Arduino IDE](https://www.arduino.cc/en/guide/cores) and
+[Arduino CLI](https://arduino.github.io/arduino-cli/latest/commands/arduino-cli_core_install/)
+can be found in the respective documentation.
+
+Then we need to make sure the following libraries are installed:
+
+- ArduinoGraphics
+- Arduino_MKRRGB
+- uTimerLib
+- WiFi101
+
+Installed instructions for
+[Arduino IDE](https://www.arduino.cc/en/guide/libraries) and
+[Arduino CLI](https://arduino.github.io/arduino-cli/latest/commands/arduino-cli_lib_install/)
+can be found in the respective documentation.
+
+We assign a fixed IP address in the space's WiFi network to the Arduino's MAC
+address. The MAC address gets printed to `Serial` on each start up. Once
+connected to the configured WLAN, the IP address is also printed to `Serial`.
+(TODO: MENTION WHERE TO FIND DOCUMENTATION FOR OUR DHCPD.)
+
+### Arduino: UDP API
+
+Once the Arduino has started successfully, it listens on the configured port
+(see [sources/arduino/config.h](sources/arduino/config.h) for the default port)
+for UDP packets and answers each incoming packet with the state of the door. The
+state is encoded as a one byte integer, where `0` stands for closed and `1`
+stands for open.
+
+In `scripts` is the Python 3 script `test_udp_api.py`, which we use to test the
+UDP API. It takes an IP address and optionally a port, queries the Arduino, and
+prints out the result.
+
+## In-Space Service
+
+## Internet Service
 
-## API
 
 ## License
 
 The authors of the Arduino code license the code under the AGPL 3.0 (see
-`LICENSE.AGPL`). The respective authors are listed in the in the preambles of
-each source file.
+`LICENSE.AGPL`). The respective authors are listed in the preambles of each
+source file.
 
 ## Dependencies
 
+The creation of the schematic image depends on the following libraries:
+
+*TikZ* published by the copyright holders under the GPL 2, the Free
+Documentation License, and the LaTeX Project Public License 1.3c
+
+*Circuitikz* published by the copyright holders under the GPL 2 and the LaTeX
+Project Public License
+
 The Arduino code depends on the following libraries:
 
-_Arduino Core_ published by the copyright holders under the LGPL 2.1 or later.
+*Arduino SAMD Boards* published by the copyright holders under the LGPL 2.1 or later.
 
-_SPI Master Library for Arduino Zero_ published by the copyright holders under
+*SPI Master Library for Arduino Zero* published by the copyright holders under
 the LGPL 2.1 or later.
 
-_Library for Arduino WiFi Shield_ published by the copyright holders under the
+*ArduinoGraphics* published by the copyright holders under the LGPL 2.1 or
+later.
+
+*Arduino_MKRRGB* published by the copyright holders under the LGPL 2.1 or later.
+
+*uTimerLib* published by the copyright holders under the LGPL 3.
+
+*WiFi101* published by the copyright holders under the
 LGPL 2.1 or later.

documentation/Makefile

@@ -0,0 +1,33 @@
+# Copyright (c):
+#
+# Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+#
+# This file is part of the KrautStatus' Arduino code.
+#
+# The Clean CommonMark library is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# The Clean CommonMark library 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 Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with the Clean CommonMark library. If not, see
+# <https://www.gnu.org/licenses/>.
+
+.PHONY: all clean
+
+all: arduino.png
+
+clean:
+	rm --recursive build
+
+arduino.png: arduino.tex build
+	pdflatex -output-directory build arduino
+	convert -density 300 build/arduino.pdf -trim -colorspace RGB arduino.png
+
+build:
+	mkdir --parents build

documentation/arduino.tex

@@ -0,0 +1,55 @@
+\documentclass[border=1mm]{standalone}
+
+\usepackage{tikz}
+\usetikzlibrary{positioning}
+\usepackage{circuitikz}
+
+\begin{document}
+
+\begin{circuitikz}[
+  chip/.style = {
+    dipchip,
+    hide numbers,
+    no topmark,
+    external pins width=0,
+    num pins=14,
+  }]
+  \ctikzset{multipoles/dipchip/width=1.6}
+
+  % Arduino MKR1000
+  \node [chip] (MKR1000) {};
+  % align=center enables line breaks in node text
+  \node [align=center, rotate=90] at (MKR1000.center){Arduino\\MKR1000};
+
+  \draw (MKR1000.n) -- ++(0,1) node[vcc]{};
+  \draw (MKR1000.s) -- ++(0,-1) node[ground] {};
+
+  \node [right, font=\tiny] at (MKR1000.bpin 4) {0};
+
+  \node [left, font=\tiny] at (MKR1000.bpin 12) {VIN};
+  \node [left, font=\tiny] at (MKR1000.bpin 11) {A3};
+  \node [left, font=\tiny] at (MKR1000.bpin 10) {A4};
+
+  % Arduino MKR RGB Shield
+  \node[chip, right=of MKR1000] (RGB) {};
+  % align=center enables line breaks in node text
+  \node [align=center, rotate=90] at (RGB.center){Arduino\\MKR RGB Shield};
+
+  \draw (RGB.s) -- ++(0, -1) node[ground]{};
+
+  \node [right, font=\tiny] at (RGB.bpin 3) {VIN};
+  \node [right, font=\tiny] at (RGB.bpin 4) {A3};
+  \node [right, font=\tiny] at (RGB.bpin 5) {A4};
+
+  \draw (MKR1000.bpin 12) -- (RGB.bpin 3);
+  \draw (MKR1000.bpin 11) -- (RGB.bpin 4);
+  \draw (MKR1000.bpin 10) -- (RGB.bpin 5);
+
+  % Reed switch
+  \draw (MKR1000.bpin 4) -- ++(-1, 0) to [normal open switch, name=R] ++(0, -2.96) node[ground]{};
+
+  \node [rotate=90, above] at (R) {Reed Switch};
+\end{circuitikz}
+
+
+\end{document}

scripts/test_udp_api.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+"""
+Test KrautStatus's UDP API for a given IP and (optionally) port.
+"""
+
+import argparse
+import ipaddress
+import socket
+
+def port(string):
+    "Convert string to an unsigend integer that is a valid port number"
+    port = int(string)
+
+    if port < 0 or port > 65535:
+        raise ValueError()
+
+    return port
+
+def main():
+    parser = argparse.ArgumentParser(__doc__)
+
+    parser.add_argument("ip",
+                        metavar="IP",
+                        type=ipaddress.ip_address,
+                        help="IP address of the KrautStatus Arduino")
+
+    parser.add_argument("port",
+                        nargs="?",
+                        metavar="PORT",
+                        default=12345,
+                        type=port,
+                        help="port that the KrautStatus Arduino listens to")
+
+    args = parser.parse_args()
+
+
+    receiver = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    receiver.bind(('0.0.0.0', args.port))
+    print(f'Listening on 0.0.0.0:{args.port}.')
+
+    sender = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    # We do not use \0 or \1 here, so that we do not trigger ourselves when
+    # testing the script locally (127.0.0.1)
+    sender.sendto(b'\2', (str(args.ip), args.port))
+    print(f'Sent null byte to {args.ip}:{args.port}.')
+
+    while True:
+        status, address = receiver.recvfrom(1)
+
+        if not address[0] == str(args.ip):
+            continue
+
+        if status[0] == 0:
+            print('Responded: door closed')
+            return
+
+        if status[0] == 1:
+            print('Resondend: door open')
+            return
+
+if __name__ == "__main__":
+    main()

source/arduino/Makefile

@@ -0,0 +1,33 @@
+# Copyright (c):
+#
+# Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+#
+# This file is part of the KrautStatus' Arduino code.
+#
+# The Clean CommonMark library is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# The Clean CommonMark library 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 Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with the Clean CommonMark library. If not, see
+# <https://www.gnu.org/licenses/>.
+
+.PHONY: all clean install
+
+all:
+	arduino-cli compile --fqbn arduino:samd:mkr1000
+
+clean:
+	rm --recursive build
+
+install:
+	PORT=$(arduino-cli board list | \
+	       grep arduino:samd:mkr1000 | \
+	       sed -e 's/ .*//g'); \
+	arduino-cli upload --fqbn arduino:samd:mkr1000 --port $$PORT

source/arduino/arduino.ino

@@ -0,0 +1,70 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <SPI.h>
+#include <uTimerLib.h>
+
+#include "config.h"
+#include "matrix.h"
+#include "sensor.h"
+#include "serial.h"
+#include "wifi.h"
+
+const unsigned long int MATRIX_UPDATE_FREQUENCY = 1;
+
+void setup() {
+  serial_setup();
+  matrix_setup();
+
+  boolean wifi_result = matrix_show_scan_and_run(wifi_setup);
+  if (!wifi_result) {
+    matrix_show_failure();
+    while(true);
+  }
+
+  sensor_setup();
+
+  start_matrix_update();
+}
+
+void loop() {
+  int packetSize = Udp.parsePacket();
+  if (packetSize) {
+    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
+    Udp.write(uint8_t(sensor_get_door_state()));
+    Udp.endPacket();
+  }
+}
+
+void start_matrix_update() {
+  TimerLib.setInterval_us(matrix_update, 1000000 / MATRIX_UPDATE_FREQUENCY);
+}
+
+void matrix_update() {
+  switch (sensor_get_door_state()) {
+  OPEN:
+    matrix_fill(GREEN);
+    break;
+  CLOSED:
+    matrix_fill(BLACK);
+    break;
+  }
+}

source/arduino/config.h

@@ -19,14 +19,15 @@ You should have received a copy of the GNU Affero General Public License along
 with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
 */
 
+#include <stdint.h>
+
 // SSID and password of the WiFi network to which we broadcast the door lock's
 // status.
-char SSID[] = "";
-char PASSWORD[] = "";
-
+const char SSID[] = "";
+const char PASSWORD[] = "";
 
 // Port on which to listen for status requests
-unsigned int PORT = 12345;
+const unsigned int SERVER_PORT = 12345;
 
 // Pin to which the reed switch is connected
-uint8_t REED_PIN = 0;
+const uint8_t SENSOR_PIN = 0;

source/arduino/matrix.cpp

@@ -0,0 +1,87 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <ArduinoGraphics.h>
+#include <Arduino_MKRRGB.h>
+#include <uTimerLib.h>
+
+#include "matrix.h"
+
+
+const uint32_t RED    = COLOR(255,   0,   0);
+const uint32_t YELLOW = COLOR(255, 255,   0);
+
+const unsigned long int SCAN_UPDATE_FREQUENCY = 25;
+
+void matrix_setup() {
+  MATRIX.begin();
+}
+
+void matrix_show_failure() {
+  MATRIX.stroke(RED);
+  MATRIX.beginDraw();
+  MATRIX.clear();
+  MATRIX.line(0, 0, MATRIX.width() - 1, MATRIX.height() - 1);
+  MATRIX.line(0, MATRIX.height() - 1, MATRIX.width() - 1, 0);
+  MATRIX.endDraw();
+}
+
+uint8_t scan_timer = 0;
+
+void matrix_paint_scan() {
+  // We paint a vertical line that oscillates between the left and right border
+  // of the matrix. Going back and forth one pixel at a time gives us as period
+  // of
+  //     2 * width - 2
+  // because we do not want to remain at the borders for one tick.
+  scan_timer += 1;
+  scan_timer %= 2 * MATRIX.width() - 2;
+
+  uint8_t position = scan_timer;
+  if(position >= MATRIX.width())
+    position = 2 * MATRIX.width() - position - 2;
+
+  MATRIX.beginDraw();
+  MATRIX.clear();
+  MATRIX.line(position, 0, position, 6);
+  MATRIX.endDraw();
+}
+
+bool matrix_show_scan_and_run(bool(*thunk)()) {
+  MATRIX.stroke(YELLOW);
+  TimerLib.setInterval_us(matrix_paint_scan, 1000000 / SCAN_UPDATE_FREQUENCY);
+
+  bool result = thunk();
+
+  TimerLib.clearTimer();
+  MATRIX.beginDraw();
+  MATRIX.clear();
+  MATRIX.endDraw();
+
+  return result;
+}
+
+void matrix_fill(uint32_t color) {
+  MATRIX.fill(color);
+  MATRIX.beginDraw();
+  MATRIX.clear();
+  MATRIX.endDraw();
+}

source/arduino/matrix.h

@@ -0,0 +1,33 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#define COLOR(r, g, b) (r << 16 | g << 8 | b)
+
+const uint32_t BLACK = COLOR(  0,   0,   0);
+const uint32_t GREEN = COLOR(  0, 255,   0);
+
+void matrix_setup();
+
+void matrix_show_failure();
+
+bool matrix_show_scan_and_run(bool(*)());
+
+void matrix_fill(uint32_t color);

source/arduino/sensor.cpp

@@ -0,0 +1,35 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <Arduino.h>
+
+#include "sensor.h"
+#include "config.h"
+
+void sensor_setup() {
+  pinMode(SENSOR_PIN, INPUT_PULLUP);
+}
+
+door_state sensor_get_door_state() {
+  if (digitalRead(SENSOR_PIN) == HIGH)
+    return OPEN;
+  return CLOSED;
+}

source/arduino/sensor.h

@@ -0,0 +1,29 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+typedef enum {
+  CLOSED = 0,
+  OPEN = 1
+} door_state;
+
+void sensor_setup();
+
+door_state sensor_get_door_state();

source/arduino/serial.cpp

@@ -0,0 +1,26 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <SPI.h>
+
+void serial_setup() {
+  Serial.begin(9600);
+}

source/arduino/serial.h

@@ -0,0 +1,22 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+void serial_setup();

source/arduino/wifi.cpp

@@ -25,82 +25,43 @@ with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
 
 #include "config.h"
 
-uint8_t OPEN = 1;
-uint8_t CLOSED = 0;
-
 WiFiUDP Udp;
 
-void setup() {
-  pinMode(REED_PIN, INPUT_PULLUP);
-
-  Serial.begin(9600);
-  while (!Serial);
-
-  if (WiFi.status() == WL_NO_SHIELD) {
-    Serial.println("No WiFI shield present");
-    // TODO: Create noShieldLoop with visual indication.
-    while (true);
+void print_mac_address() {
+  uint8_t mac[6];
+  WiFi.macAddress(mac);
+  Serial.print("MAC: ");
+  for(unsigned int i = 5; i > 0; --i) {
+    Serial.print(mac[i], HEX);
+    Serial.print(":");
+  }
+  Serial.println(mac[0], HEX);
 }
 
+boolean wifi_setup() {
+  if (WiFi.status() == WL_NO_SHIELD) {
+    Serial.println("No WiFI shield present");
+    return false;
+  }
+
+  print_mac_address();
+
   while (true) {
-    // TODO: Visually indicate that we are trying to connect
     Serial.print("Connecting to SSID: ");
     Serial.println(SSID);
-    status = WiFi.begin(SSID, PASSWORD);
 
-    if (status == WL_CONNECTED) {
+    if (WiFi.begin(SSID, PASSWORD) == WL_CONNECTED) {
       break;
     }
 
-    // TODO: Visually indicate that we waiting for trying to connect again
     delay(10000);
   }
 
-  printNetworkInfo();
-
-}
-
-void loop() {
-  int reed_state = digitalRead(REED_PIN);
-
-  int packetSize = Udp.readPacket();
-  if (packetSize) {
-    Udp.beginPacket(udp.remoteIP(), Udp.remotePort());
-
-    if (reed_state == HIGH) {
-      Udp.write(CLOSED);
-    } else {
-      Udp.write(OPEN);
-    }
-
-    Udp.endPacket();
-  }
-  // TODO: Visually indicate open/closed state.
-}
-
-
-void printNetworkInfo() {
-
-  Serial.print("Connect to WiFi");
-
-  IPAddress ip = WiFi.localIP();
+  Serial.println("Connect to WiFi");
   Serial.print("IP Address: ");
-  Serial.println(ip);
+  Serial.println(WiFi.localIP());
 
-  byte mac[6];
-  WiFi.macAddress(mac);
-  Serial.print("MAC address: ");
-  for (int i = 5; i >= 0; --i) {
-    if (mac[i] < 16) {
-      Serial.print("0");
-    }
-
-    Serial.print(mac[i], HEX);
-
-    if (i > 0) {
-      Serial.print(":");
-    }
-  }
-  Serial.println();
+  Udp.begin(SERVER_PORT);
 
+  return true;
 }

source/arduino/wifi.h

@@ -0,0 +1,27 @@
+/*
+Copyright (c):
+
+Philipp Matthias Schäfer (philipp.matthias.schaefer@posteo.de), 2020
+
+This file is part of the KrautStatus' Arduino code.
+
+The Clean CommonMark library is free software: you can redistribute it and/or
+modify it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or (at your
+option) any later version.
+
+The Clean CommonMark library 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 Affero General Public License
+for more details.
+
+You should have received a copy of the GNU Affero General Public License along
+with the Clean CommonMark library. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <WiFi101.h>
+#include <WiFiUdp.h>
+
+extern WiFiUDP Udp;
+
+bool wifi_setup();