wip

8 files changed, 656 insertions, 639 deletions

diff --git a/slides/images/ip-encapsulation.pgf b/slides/images/ip-encapsulation.pgf
new file mode 100644
index 0000000..34ba423
--- /dev/null
+++ b/slides/images/ip-encapsulation.pgf
@@ -0,0 +1,25 @@
+\begin{tikzpicture}[
+mybox/.style={
+	draw,
+	rectangle,
+	minimum height=1 cm,
+	anchor=west,
+	align=center,
+	font=\bfseries}
+]
+
+%\draw (0,0) rectangle (3cm, 1cm) {wat};
+
+\node at (0 cm, 0 cm) [mybox, minimum width=2cm, text width=1.7cm] {Frame header};
+\node at (2 cm, 0 cm) [mybox, minimum width=6cm] {Frame data};
+\node at (8 cm, 0 cm) [mybox, minimum width=2cm, text width=1.7cm] {Frame footer};
+
+\node at (2 cm, 1.1 cm) [mybox, minimum width=2cm] {IP header};
+\node at (4 cm, 1.1 cm) [mybox, minimum width=4cm] {IP Data};
+
+\node at (4 cm, 2.2 cm) [mybox, minimum width=2cm, text width=1.7 cm] {UDP header};
+\node at (6 cm, 2.2 cm) [mybox, minimum width=2cm, text width=1.7 cm] {UDP Data};
+
+\node at (6 cm, 3.3 cm) [mybox, minimum width=2cm, text width=1.7 cm] {Data};
+
+\end{tikzpicture}
diff --git a/slides/images/tcpip.pgf b/slides/images/tcpip.pgf
new file mode 100644
index 0000000..def5a31
--- /dev/null
+++ b/slides/images/tcpip.pgf
@@ -0,0 +1,12 @@
+\begin{tikzpicture}[
+mybox/.style={draw, rectangle, minimum width=4cm, minimum height=1 cm,font=\bfseries}
+]
+
+%\draw (0,0) rectangle (3cm, 1cm) {wat};
+
+\node at (0, -0) [mybox] {Application};
+\node at (0, -1) [mybox] {Transport};
+\node at (0, -2) [mybox] {Internet};
+\node at (0, -3)[mybox] {Network interface};
+
+\end{tikzpicture}
diff --git a/slides/toc.md b/slides/toc.md
index 76e65a6..7b7e857 100644
--- a/slides/toc.md
+++ b/slides/toc.md
@@ -1,3 +1,14 @@
+* NodeMCU
+    * NodeMCU hardware
+    * NodeMCU hardware
+    * ESP8266 software layers
+    * ESP8266 + Arduino
+    * Arduino IDE
+    * Arduino code structure
+    * Arduino file structure
+    * Generic Arduino APIs
+    * ESP Arduino APIs
+    * ESP Arduino APIs
 * What is IoT
     * What is IoT
     * IoT is just a concept
@@ -23,34 +34,24 @@
     * Details: IP
     * Details: IP
     * Details: UDP
-* Lecture: ESP8266
-    * NodeMCU hardware
-    * NodeMCU hardware
-    * ESP8266 software layers
-    * ESP8266 + Arduino
-    * Arduino IDE
-    * Arduino code structure
-    * Arduino file structure
-    * Generic Arduino APIs
-    * ESP Arduino APIs
-    * ESP Arduino APIs
 * Lecture: MQTT
     * MQTT
+    * Device and application architecture with MQTT
     * MQTT - Implementations
     * MQTT Cloud Connectors
     * MQTT - The protocol
     * MQTT - The protocol - MQTT Packet
-    * MQTT - The protocol - Keep alive
+    * MQTT Connect
     * MQTT - The protocol - MQTT Topic
     * MQTT - The protocol - Retained message
     * MQTT - The protocol - Will message
-    * MQTT - The protocol - Client id
-    * Device and application architecture with MQTT
     * MQTT Topic
     * MQTT on Arduino
     * MQTT on Arduino
     * Assignment
     * MQTT topic architecture
+    * MQTT topic architecture
+    * MQTT topic architecture
     * MQTT - Patterns
     * Assignment 
     * Assignment 
diff --git a/slides/what-is-iot-reveal.html b/slides/what-is-iot-reveal.html
index b63657a..2990fce 100644
--- a/slides/what-is-iot-reveal.html
+++ b/slides/what-is-iot-reveal.html
@@ -105,6 +105,107 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
   <p class="author">Trygve Laugstøl &lt;trygvis@trygvis.io&gt;</p>
 </section>
 
+<section><section id="nodemcu" class="title-slide slide level1"><h1>NodeMCU</h1></section><section id="nodemcu-hardware" class="slide level2">
+<h2>NodeMCU hardware</h2>
+<p><img data-src="images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg" /></p>
+</section><section id="nodemcu-hardware-1" class="slide level2">
+<h2>NodeMCU hardware</h2>
+
+</section><section id="esp8266-software-layers" class="slide level2">
+<h2>ESP8266 software layers</h2>
+
+</section><section id="esp8266-arduino" class="slide level2">
+<h2>ESP8266 + Arduino</h2>
+<ul>
+<li>Standard Arduino IDE</li>
+<li>ESP8266 Arduino core
+<ul>
+<li>https://github.com/esp8266/Arduino</li>
+</ul></li>
+</ul>
+</section><section id="arduino-ide" class="slide level2">
+<h2>Arduino IDE</h2>
+<p><img data-src="images/arduino-ide.png" /></p>
+</section><section id="arduino-code-structure" class="slide level2">
+<h2>Arduino code structure</h2>
+<div class="sourceCode" id="cb1"><pre class="sourceCode .c++"><code class="sourceCode cpp"><a class="sourceLine" id="cb1-1" data-line-number="1"><span class="dt">void</span> setup() {</a>
+<a class="sourceLine" id="cb1-2" data-line-number="2">    <span class="co">// Called once</span></a>
+<a class="sourceLine" id="cb1-3" data-line-number="3">}</a>
+<a class="sourceLine" id="cb1-4" data-line-number="4"></a>
+<a class="sourceLine" id="cb1-5" data-line-number="5"><span class="dt">void</span> loop() {</a>
+<a class="sourceLine" id="cb1-6" data-line-number="6">    <span class="co">// Called repeatedly</span></a>
+<a class="sourceLine" id="cb1-7" data-line-number="7">}</a></code></pre></div>
+<aside class="notes">
+<p>MCU programming is often structured into:</p>
+<ul>
+<li>Configure
+<ul>
+<li>CPU</li>
+<li>GPIO ports</li>
+<li>MCU’s peripherals</li>
+<li>The rest of the board</li>
+<li>Configure application and callbacks.</li>
+</ul></li>
+<li>Sleep</li>
+</ul>
+<p>Arduino chooses to run the cpu at 100% instead of the sleep step..</p>
+</aside>
+</section><section id="arduino-file-structure" class="slide level2">
+<h2>Arduino file structure</h2>
+<pre><code>foo/
+  foo.ino
+  config.h</code></pre>
+<aside class="notes">
+<p><code>foo.ino</code> must always be in a <code>foo</code> directory.</p>
+<p>config.h is created by “new tab”.</p>
+</aside>
+</section><section id="generic-arduino-apis" class="slide level2">
+<h2>Generic Arduino APIs</h2>
+<div class="sourceCode" id="cb3"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb3-1" data-line-number="1"><span class="co">// Pin: D0, D1, etc.</span></a>
+<a class="sourceLine" id="cb3-2" data-line-number="2"><span class="co">// Mode: OUTPUT, INPUT, INPUT_PULLUP</span></a>
+<a class="sourceLine" id="cb3-3" data-line-number="3"><span class="dt">void</span> pinMode(<span class="dt">uint8_t</span> pin, <span class="dt">uint8_t</span> mode);</a>
+<a class="sourceLine" id="cb3-4" data-line-number="4"></a>
+<a class="sourceLine" id="cb3-5" data-line-number="5"><span class="co">// State: HIGH, LOW, true/false, 1/0</span></a>
+<a class="sourceLine" id="cb3-6" data-line-number="6"><span class="dt">void</span> digitalWrite(<span class="dt">uint8_t</span> pin, <span class="dt">uint8_t</span> state);</a>
+<a class="sourceLine" id="cb3-7" data-line-number="7"><span class="dt">int</span> digitalRead(<span class="dt">uint8_t</span> pin);</a>
+<a class="sourceLine" id="cb3-8" data-line-number="8"></a>
+<a class="sourceLine" id="cb3-9" data-line-number="9"><span class="dt">unsigned</span> <span class="dt">long</span> now millis();</a>
+<a class="sourceLine" id="cb3-10" data-line-number="10"><span class="dt">unsigned</span> <span class="dt">long</span> now micros();</a></code></pre></div>
+</section><section id="esp-arduino-apis" class="slide level2">
+<h2>ESP Arduino APIs</h2>
+<div class="sourceCode" id="cb4"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb4-1" data-line-number="1"><span class="kw">class</span> {</a>
+<a class="sourceLine" id="cb4-2" data-line-number="2">    <span class="dt">void</span> restart();</a>
+<a class="sourceLine" id="cb4-3" data-line-number="3">    <span class="dt">uint32_t</span> getFreeHeap();</a>
+<a class="sourceLine" id="cb4-4" data-line-number="4">    <span class="dt">uint32_t</span> getChipId();</a>
+<a class="sourceLine" id="cb4-5" data-line-number="5"></a>
+<a class="sourceLine" id="cb4-6" data-line-number="6">    ...</a>
+<a class="sourceLine" id="cb4-7" data-line-number="7">} ESP;</a>
+<a class="sourceLine" id="cb4-8" data-line-number="8"></a>
+<a class="sourceLine" id="cb4-9" data-line-number="9"><span class="co">// Usage</span></a>
+<a class="sourceLine" id="cb4-10" data-line-number="10">ESP.restart();</a></code></pre></div>
+</section><section id="esp-arduino-apis-1" class="slide level2">
+<h2>ESP Arduino APIs</h2>
+<div class="sourceCode" id="cb5"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb5-1" data-line-number="1"><span class="kw">class</span> {</a>
+<a class="sourceLine" id="cb5-2" data-line-number="2">    String macAddress();</a>
+<a class="sourceLine" id="cb5-3" data-line-number="3"></a>
+<a class="sourceLine" id="cb5-4" data-line-number="4">    <span class="dt">wl_status_t</span> status();</a>
+<a class="sourceLine" id="cb5-5" data-line-number="5">    <span class="dt">int32_t</span> RSSI();</a>
+<a class="sourceLine" id="cb5-6" data-line-number="6"></a>
+<a class="sourceLine" id="cb5-7" data-line-number="7">    IPAddress localIP();</a>
+<a class="sourceLine" id="cb5-8" data-line-number="8">    IPAddress subnetMask();</a>
+<a class="sourceLine" id="cb5-9" data-line-number="9">    IPAddress gatewayIP();</a>
+<a class="sourceLine" id="cb5-10" data-line-number="10">    IPAddress dnsIP(<span class="dt">uint8_t</span> dns_no = <span class="dv">0</span>);</a>
+<a class="sourceLine" id="cb5-11" data-line-number="11"></a>
+<a class="sourceLine" id="cb5-12" data-line-number="12">    ...</a>
+<a class="sourceLine" id="cb5-13" data-line-number="13">} WiFi;</a>
+<a class="sourceLine" id="cb5-14" data-line-number="14"></a>
+<a class="sourceLine" id="cb5-15" data-line-number="15"><span class="co">// Usage:</span></a>
+<a class="sourceLine" id="cb5-16" data-line-number="16"></a>
+<a class="sourceLine" id="cb5-17" data-line-number="17">Serial.println(WiFi.localIP().toString());</a></code></pre></div>
+<aside class="notes">
+<p>http://arduino-esp8266.readthedocs.io/en/latest/libraries.html</p>
+</aside>
+</section></section>
 <section><section id="what-is-iot" class="title-slide slide level1"><h1>What is IoT</h1></section><section id="what-is-iot-1" class="slide level2">
 <h2>What is IoT</h2>
 <ul>
@@ -455,108 +556,6 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
 </section><section id="details-udp" class="slide level2">
 <h2>Details: UDP</h2>
 
-<p>TODO: add payload to “ip packets”</p>
-</section></section>
-<section><section id="lecture-esp8266" class="title-slide slide level1"><h1>Lecture: ESP8266</h1></section><section id="nodemcu-hardware" class="slide level2">
-<h2>NodeMCU hardware</h2>
-<p><img data-src="images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg" /></p>
-</section><section id="nodemcu-hardware-1" class="slide level2">
-<h2>NodeMCU hardware</h2>
-
-</section><section id="esp8266-software-layers" class="slide level2">
-<h2>ESP8266 software layers</h2>
-
-</section><section id="esp8266-arduino" class="slide level2">
-<h2>ESP8266 + Arduino</h2>
-<ul>
-<li>Standard Arduino IDE</li>
-<li>ESP8266 Arduino core
-<ul>
-<li>https://github.com/esp8266/Arduino</li>
-</ul></li>
-</ul>
-</section><section id="arduino-ide" class="slide level2">
-<h2>Arduino IDE</h2>
-<p><img data-src="images/arduino-ide.png" /></p>
-</section><section id="arduino-code-structure" class="slide level2">
-<h2>Arduino code structure</h2>
-<div class="sourceCode" id="cb1"><pre class="sourceCode .c++"><code class="sourceCode cpp"><a class="sourceLine" id="cb1-1" data-line-number="1"><span class="dt">void</span> setup() {</a>
-<a class="sourceLine" id="cb1-2" data-line-number="2">    <span class="co">// Called once</span></a>
-<a class="sourceLine" id="cb1-3" data-line-number="3">}</a>
-<a class="sourceLine" id="cb1-4" data-line-number="4"></a>
-<a class="sourceLine" id="cb1-5" data-line-number="5"><span class="dt">void</span> loop() {</a>
-<a class="sourceLine" id="cb1-6" data-line-number="6">    <span class="co">// Called repeatedly</span></a>
-<a class="sourceLine" id="cb1-7" data-line-number="7">}</a></code></pre></div>
-<aside class="notes">
-<p>MCU programming is often structured into:</p>
-<ul>
-<li>Configure
-<ul>
-<li>CPU</li>
-<li>GPIO ports</li>
-<li>MCU’s peripherals</li>
-<li>The rest of the board</li>
-<li>Configure application and callbacks.</li>
-</ul></li>
-<li>Sleep</li>
-</ul>
-<p>Arduino chooses to run the cpu at 100% instead of the sleep step..</p>
-</aside>
-</section><section id="arduino-file-structure" class="slide level2">
-<h2>Arduino file structure</h2>
-<pre><code>foo/
-  foo.ino
-  config.h</code></pre>
-<aside class="notes">
-<p><code>foo.ino</code> must always be in a <code>foo</code> directory.</p>
-<p>config.h is created by “new tab”.</p>
-</aside>
-</section><section id="generic-arduino-apis" class="slide level2">
-<h2>Generic Arduino APIs</h2>
-<div class="sourceCode" id="cb3"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb3-1" data-line-number="1"><span class="co">// Pin: D0, D1, etc.</span></a>
-<a class="sourceLine" id="cb3-2" data-line-number="2"><span class="co">// Mode: OUTPUT, INPUT, INPUT_PULLUP</span></a>
-<a class="sourceLine" id="cb3-3" data-line-number="3"><span class="dt">void</span> pinMode(<span class="dt">uint8_t</span> pin, <span class="dt">uint8_t</span> mode);</a>
-<a class="sourceLine" id="cb3-4" data-line-number="4"></a>
-<a class="sourceLine" id="cb3-5" data-line-number="5"><span class="co">// State: HIGH, LOW, true/false, 1/0</span></a>
-<a class="sourceLine" id="cb3-6" data-line-number="6"><span class="dt">void</span> digitalWrite(<span class="dt">uint8_t</span> pin, <span class="dt">uint8_t</span> state);</a>
-<a class="sourceLine" id="cb3-7" data-line-number="7"><span class="dt">int</span> digitalRead(<span class="dt">uint8_t</span> pin);</a>
-<a class="sourceLine" id="cb3-8" data-line-number="8"></a>
-<a class="sourceLine" id="cb3-9" data-line-number="9"><span class="dt">unsigned</span> <span class="dt">long</span> now millis();</a>
-<a class="sourceLine" id="cb3-10" data-line-number="10"><span class="dt">unsigned</span> <span class="dt">long</span> now micros();</a></code></pre></div>
-</section><section id="esp-arduino-apis" class="slide level2">
-<h2>ESP Arduino APIs</h2>
-<div class="sourceCode" id="cb4"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb4-1" data-line-number="1"><span class="kw">class</span> {</a>
-<a class="sourceLine" id="cb4-2" data-line-number="2">    <span class="dt">void</span> restart();</a>
-<a class="sourceLine" id="cb4-3" data-line-number="3">    <span class="dt">uint32_t</span> getFreeHeap();</a>
-<a class="sourceLine" id="cb4-4" data-line-number="4">    <span class="dt">uint32_t</span> getChipId();</a>
-<a class="sourceLine" id="cb4-5" data-line-number="5"></a>
-<a class="sourceLine" id="cb4-6" data-line-number="6">    ...</a>
-<a class="sourceLine" id="cb4-7" data-line-number="7">} ESP;</a>
-<a class="sourceLine" id="cb4-8" data-line-number="8"></a>
-<a class="sourceLine" id="cb4-9" data-line-number="9"><span class="co">// Usage</span></a>
-<a class="sourceLine" id="cb4-10" data-line-number="10">ESP.restart();</a></code></pre></div>
-</section><section id="esp-arduino-apis-1" class="slide level2">
-<h2>ESP Arduino APIs</h2>
-<div class="sourceCode" id="cb5"><pre class="sourceCode cpp"><code class="sourceCode cpp"><a class="sourceLine" id="cb5-1" data-line-number="1"><span class="kw">class</span> {</a>
-<a class="sourceLine" id="cb5-2" data-line-number="2">    String macAddress();</a>
-<a class="sourceLine" id="cb5-3" data-line-number="3"></a>
-<a class="sourceLine" id="cb5-4" data-line-number="4">    <span class="dt">wl_status_t</span> status();</a>
-<a class="sourceLine" id="cb5-5" data-line-number="5">    <span class="dt">int32_t</span> RSSI();</a>
-<a class="sourceLine" id="cb5-6" data-line-number="6"></a>
-<a class="sourceLine" id="cb5-7" data-line-number="7">    IPAddress localIP();</a>
-<a class="sourceLine" id="cb5-8" data-line-number="8">    IPAddress subnetMask();</a>
-<a class="sourceLine" id="cb5-9" data-line-number="9">    IPAddress gatewayIP();</a>
-<a class="sourceLine" id="cb5-10" data-line-number="10">    IPAddress dnsIP(<span class="dt">uint8_t</span> dns_no = <span class="dv">0</span>);</a>
-<a class="sourceLine" id="cb5-11" data-line-number="11"></a>
-<a class="sourceLine" id="cb5-12" data-line-number="12">    ...</a>
-<a class="sourceLine" id="cb5-13" data-line-number="13">} WiFi;</a>
-<a class="sourceLine" id="cb5-14" data-line-number="14"></a>
-<a class="sourceLine" id="cb5-15" data-line-number="15"><span class="co">// Usage:</span></a>
-<a class="sourceLine" id="cb5-16" data-line-number="16"></a>
-<a class="sourceLine" id="cb5-17" data-line-number="17">Serial.println(WiFi.localIP().toString());</a></code></pre></div>
-<aside class="notes">
-<p>http://arduino-esp8266.readthedocs.io/en/latest/libraries.html</p>
-</aside>
 </section></section>
 <section><section id="lecture-mqtt" class="title-slide slide level1"><h1>Lecture: MQTT</h1></section><section id="mqtt" class="slide level2">
 <h2>MQTT</h2>
@@ -570,6 +569,9 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
 <p>Has UDP-like semantics with “fire and forget” but on a higher level (the message always have to be delivered and ACKed by the broker, not it’s final recipient.</p>
 <p>Version 3.1.1 er den som gjelder, V 3.1 er rar, de andre finnes ikke (før standardisering).</p>
 </aside>
+</section><section id="device-and-application-architecture-with-mqtt" class="slide level2">
+<h2>Device and application architecture with MQTT</h2>
+
 </section><section id="mqtt---implementations" class="slide level2">
 <h2>MQTT - Implementations</h2>
 <ul>
@@ -647,9 +649,25 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
 <p>Only packet type + flags (1 byte) is required, everything else is optional.</p>
 <p>The size field is variable length encoded, 0-127 bytes is 1 byte, 128-16383 use 2 bytes etc, up to 4 bytes for 256MB payload.</p>
 </aside>
-</section><section id="mqtt---the-protocol---keep-alive" class="slide level2">
-<h2>MQTT - The protocol - Keep alive</h2>
-<p>TODO</p>
+</section><section id="mqtt-connect" class="slide level2">
+<h2>MQTT Connect</h2>
+<ul>
+<li><code>CONNECT</code>
+<ul>
+<li><code>clientId</code></li>
+<li><code>username</code></li>
+<li><code>password</code></li>
+<li><code>keepAlive</code></li>
+</ul></li>
+</ul>
+<!-- -->
+<ul>
+<li>Keep alive
+<ul>
+<li><code>PINGREQ</code></li>
+<li><code>PINGRESP</code></li>
+</ul></li>
+</ul>
 </section><section id="mqtt---the-protocol---mqtt-topic" class="slide level2">
 <h2>MQTT - The protocol - MQTT Topic</h2>
 <ul>
@@ -713,12 +731,6 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
 <li><code>0</code></li>
 </ul></li>
 </ol>
-</section><section id="mqtt---the-protocol---client-id" class="slide level2">
-<h2>MQTT - The protocol - Client id</h2>
-<p>TODO</p>
-</section><section id="device-and-application-architecture-with-mqtt" class="slide level2">
-<h2>Device and application architecture with MQTT</h2>
-
 </section><section id="mqtt-topic" class="slide level2">
 <h2>MQTT Topic</h2>
 <p>The temperature sensor:</p>
@@ -806,9 +818,12 @@ code span.wa { color: #60a0b0; font-weight: bold; font-style: italic; } /* Warni
 <li><code>myapp/$device-id/command</code></li>
 </ul></li>
 </ul>
-<aside class="notes">
+</section><section id="mqtt-topic-architecture-1" class="slide level2">
+<h2>MQTT topic architecture</h2>
+
+</section><section id="mqtt-topic-architecture-2" class="slide level2">
+<h2>MQTT topic architecture</h2>
 
-</aside>
 </section><section id="mqtt---patterns" class="slide level2">
 <h2>MQTT - Patterns</h2>
 <ul>
diff --git a/slides/what-is-iot-slides.pdf b/slides/what-is-iot-slides.pdf
index 0787197..18256ff 100644
--- a/slides/what-is-iot-slides.pdf
+++ b/slides/what-is-iot-slides.pdf
diff --git a/slides/what-is-iot-slides.tex b/slides/what-is-iot-slides.tex
index 0901294..6da20bb 100644
--- a/slides/what-is-iot-slides.tex
+++ b/slides/what-is-iot-slides.tex
@@ -1,3 +1,249 @@
+\hypertarget{nodemcu}{%
+\section{NodeMCU}\label{nodemcu}}
+
+\begin{frame}{NodeMCU hardware}
+\protect\hypertarget{nodemcu-hardware}{}
+
+\includegraphics{images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg}
+
+\end{frame}
+
+\begin{frame}{NodeMCU hardware}
+\protect\hypertarget{nodemcu-hardware-1}{}
+
+\begin{center}
+\begin{tikzpicture}
+
+\path
+    (0, 0) node(flash)[draw, rectangle,
+    minimum height=1cm, minimum width=2cm] {Flash}
+
+    (0, 1.5) node(esp8266)[draw, rectangle,
+    minimum height=1cm, minimum width=2cm] {ESP8266}
+
+    (3.5, 1.5) node(cp201x)[draw, rectangle,
+    minimum height=0.75cm, minimum width=1cm]
+    {CP201x}
+
+    (5.5, 1.5) node(usb)[]
+    {USB}
+;
+
+\draw[-] (esp8266) -- node[node font=\footnotesize, right]{QSPI} (flash);
+\draw[-] (esp8266) -- node[node font=\footnotesize, above]{UART} (cp201x) -- (usb);
+
+\node[rectangle, draw, fit=(esp8266) (flash), inner sep=2 mm,
+    label={[name=esp12_label,anchor=south]ESP-12}]
+    (esp12){};
+
+\node[rectangle, draw, thick, fit=(esp12_label) (esp12) (cp201x), inner sep=3 mm,
+    label={[anchor=north]south:NodeMCU}]
+    (nodemcu){};
+
+\end{tikzpicture}
+
+\end{center}
+
+\end{frame}
+
+\begin{frame}{ESP8266 software layers}
+\protect\hypertarget{esp8266-software-layers}{}
+
+\begin{center}
+\begin{tikzpicture}
+
+\node (rect_hw) [rectangle, draw, anchor=south west,
+    minimum width=6 cm, minimum height=1 cm,
+    label={[anchor=south]center:ESP8266 Hardware}] at (0, 0) {};
+
+\draw[thick] (-0.5, 1.25) -- (6.5, 1.25) ;
+
+\node  [rectangle, draw, anchor=south west,
+    minimum width=4 cm, minimum height=1 cm,
+    label={[anchor=south]center:ESP SDK}] at (0, 1.5) {};
+
+\node [rectangle, draw, anchor=south west,
+    minimum width=2 cm, minimum height=1 cm,
+    label={[align=center, text width=1cm]center:GCC  libc}] at (4, 1.5) {};
+
+\node [rectangle, draw, anchor=south west,
+    minimum width=6 cm, minimum height=1 cm,
+    label={[anchor=south]center:ESP interface}] at (0, 2.5) {};
+
+\node [rectangle, draw, anchor=south west,
+    minimum width=2 cm, minimum height=1 cm,
+    label={[align=center, text width= 2cm]center:Generic Arduino}] at (0, 3.5) {};
+
+\node [rectangle, draw, anchor=south west,
+    minimum width=2 cm, minimum height=1 cm,
+    label={[align=center, text width= 2cm]center:Ethernet}] at (2, 3.5) {};
+
+\node [rectangle, draw, anchor=south west,
+    minimum width=2 cm, minimum height=1 cm,
+    label={[align=center, text width= 2cm]center:ESP APIs}] at (4, 3.5) {};
+
+\draw [decorate, decoration={brace,amplitude=5pt, raise=-4pt}] (-0.5,2.5) -- (-0.5,4.5) node [black,midway,rotate=90, above] {Arduino};
+
+
+\end{tikzpicture}
+
+\end{center}
+
+\end{frame}
+
+\begin{frame}{ESP8266 + Arduino}
+\protect\hypertarget{esp8266-arduino}{}
+
+\begin{itemize}
+\tightlist
+\item
+  Standard Arduino IDE
+\item
+  ESP8266 Arduino core
+
+  \begin{itemize}
+  \tightlist
+  \item
+    https://github.com/esp8266/Arduino
+  \end{itemize}
+\end{itemize}
+
+\end{frame}
+
+\begin{frame}{Arduino IDE}
+\protect\hypertarget{arduino-ide}{}
+
+\includegraphics{images/arduino-ide.png}
+
+\end{frame}
+
+\begin{frame}[fragile]{Arduino code structure}
+\protect\hypertarget{arduino-code-structure}{}
+
+\begin{Shaded}
+\begin{Highlighting}[]
+\DataTypeTok{void}\NormalTok{ setup() \{}
+    \CommentTok{// Called once}
+\NormalTok{\}}
+
+\DataTypeTok{void}\NormalTok{ loop() \{}
+    \CommentTok{// Called repeatedly}
+\NormalTok{\}}
+\end{Highlighting}
+\end{Shaded}
+
+\note{MCU programming is often structured into:
+
+\begin{itemize}
+\tightlist
+\item
+  Configure
+
+  \begin{itemize}
+  \tightlist
+  \item
+    CPU
+  \item
+    GPIO ports
+  \item
+    MCU’s peripherals
+  \item
+    The rest of the board
+  \item
+    Configure application and callbacks.
+  \end{itemize}
+\item
+  Sleep
+\end{itemize}
+
+Arduino chooses to run the cpu at 100\% instead of the sleep step..}
+
+\end{frame}
+
+\begin{frame}[fragile]{Arduino file structure}
+\protect\hypertarget{arduino-file-structure}{}
+
+\begin{verbatim}
+foo/
+  foo.ino
+  config.h
+\end{verbatim}
+
+\note{\texttt{foo.ino} must always be in a \texttt{foo} directory.
+
+config.h is created by “new tab”.}
+
+\end{frame}
+
+\begin{frame}[fragile]{Generic Arduino APIs}
+\protect\hypertarget{generic-arduino-apis}{}
+
+\begin{Shaded}
+\begin{Highlighting}[]
+\CommentTok{// Pin: D0, D1, etc.}
+\CommentTok{// Mode: OUTPUT, INPUT, INPUT_PULLUP}
+\DataTypeTok{void}\NormalTok{ pinMode(}\DataTypeTok{uint8_t}\NormalTok{ pin, }\DataTypeTok{uint8_t}\NormalTok{ mode);}
+
+\CommentTok{// State: HIGH, LOW, true/false, 1/0}
+\DataTypeTok{void}\NormalTok{ digitalWrite(}\DataTypeTok{uint8_t}\NormalTok{ pin, }\DataTypeTok{uint8_t}\NormalTok{ state);}
+\DataTypeTok{int}\NormalTok{ digitalRead(}\DataTypeTok{uint8_t}\NormalTok{ pin);}
+
+\DataTypeTok{unsigned} \DataTypeTok{long}\NormalTok{ now millis();}
+\DataTypeTok{unsigned} \DataTypeTok{long}\NormalTok{ now micros();}
+\end{Highlighting}
+\end{Shaded}
+
+\end{frame}
+
+\begin{frame}[fragile]{ESP Arduino APIs}
+\protect\hypertarget{esp-arduino-apis}{}
+
+\begin{Shaded}
+\begin{Highlighting}[]
+\KeywordTok{class}\NormalTok{ \{}
+    \DataTypeTok{void}\NormalTok{ restart();}
+    \DataTypeTok{uint32_t}\NormalTok{ getFreeHeap();}
+    \DataTypeTok{uint32_t}\NormalTok{ getChipId();}
+
+\NormalTok{    ...}
+\NormalTok{\} ESP;}
+
+\CommentTok{// Usage}
+\NormalTok{ESP.restart();}
+\end{Highlighting}
+\end{Shaded}
+
+\end{frame}
+
+\begin{frame}[fragile]{ESP Arduino APIs}
+\protect\hypertarget{esp-arduino-apis-1}{}
+
+\begin{Shaded}
+\begin{Highlighting}[]
+\KeywordTok{class}\NormalTok{ \{}
+\NormalTok{    String macAddress();}
+
+    \DataTypeTok{wl_status_t}\NormalTok{ status();}
+    \DataTypeTok{int32_t}\NormalTok{ RSSI();}
+
+\NormalTok{    IPAddress localIP();}
+\NormalTok{    IPAddress subnetMask();}
+\NormalTok{    IPAddress gatewayIP();}
+\NormalTok{    IPAddress dnsIP(}\DataTypeTok{uint8_t}\NormalTok{ dns_no = }\DecValTok{0}\NormalTok{);}
+
+\NormalTok{    ...}
+\NormalTok{\} WiFi;}
+
+\CommentTok{// Usage:}
+
+\NormalTok{Serial.println(WiFi.localIP().toString());}
+\end{Highlighting}
+\end{Shaded}
+
+\note{http://arduino-esp8266.readthedocs.io/en/latest/libraries.html}
+
+\end{frame}
+
 \hypertarget{what-is-iot}{%
 \section{What is IoT}\label{what-is-iot}}
 
@@ -289,52 +535,82 @@ TX\strut
 
 \end{frame}
 
-\begin{frame}{OSI model}
-\protect\hypertarget{osi-model}{}
+\begin{frame}{TCP/IP Layers}
+\protect\hypertarget{tcpip-layers}{}
 
-\begin{enumerate}
-[1.]
-\tightlist
-\item
-  Physical Layer
-\item
-  Data Link Layer
-\item
-  Network Layer
-\item
-  Transport Layer
-\item
-  Session Layer
-\item
-  Presentation Layer
-\item
-  Application Layer
-\end{enumerate}
+\begin{center}
+\begin{tikzpicture}[
+mybox/.style={draw, rectangle, minimum width=4cm, minimum height=1 cm,font=\bfseries}
+]
 
-\begin{itemize}
-\tightlist
-\item
-  \href{https://en.wikipedia.org/wiki/OSI_model}{Wikipedia: OSI model}
-\item
-  \href{https://en.wikipedia.org/wiki/OSI_model\#Examples}{Wikipedia:
-  OSI model\#Examples}
-\end{itemize}
+%\draw (0,0) rectangle (3cm, 1cm) {wat};
 
-\note{Does not match the TCP/IP stack very closely.}
+\node at (0, -0) [mybox] {Application};
+\node at (0, -1) [mybox] {Transport};
+\node at (0, -2) [mybox] {Internet};
+\node at (0, -3)[mybox] {Network interface};
+
+\end{tikzpicture}
+
+\end{center}
 
 \end{frame}
 
-\begin{frame}{Layer 1: Physical Layer}
-\protect\hypertarget{layer-1-physical-layer}{}
+\begin{frame}{Packet encapsulation}
+\protect\hypertarget{packet-encapsulation}{}
+
+\begin{center}
+\begin{tikzpicture}[
+mybox/.style={
+    draw,
+    rectangle,
+    minimum height=1 cm,
+    anchor=west,
+    align=center,
+    font=\bfseries}
+]
+
+%\draw (0,0) rectangle (3cm, 1cm) {wat};
+
+\node at (0 cm, 0 cm) [mybox, minimum width=2cm, text width=1.7cm] {Frame header};
+\node at (2 cm, 0 cm) [mybox, minimum width=6cm] {Frame data};
+\node at (8 cm, 0 cm) [mybox, minimum width=2cm, text width=1.7cm] {Frame footer};
+
+\node at (2 cm, 1.1 cm) [mybox, minimum width=2cm] {IP header};
+\node at (4 cm, 1.1 cm) [mybox, minimum width=4cm] {IP Data};
+
+\node at (4 cm, 2.2 cm) [mybox, minimum width=2cm, text width=1.7 cm] {UDP header};
+\node at (6 cm, 2.2 cm) [mybox, minimum width=2cm, text width=1.7 cm] {UDP Data};
+
+\node at (6 cm, 3.3 cm) [mybox, minimum width=2cm, text width=1.7 cm] {Data};
+
+\end{tikzpicture}
+
+\end{center}
+
+\end{frame}
+
+\begin{frame}{Network interface}
+\protect\hypertarget{network-interface}{}
 
 \begin{itemize}
 \tightlist
 \item
-  10BASE5, 10BASE2
-\item
-  10BASE-T / 100BASE-TX / 1000BASE-TX
+  Ethernet
+
+  \begin{itemize}
+  \tightlist
+  \item
+    10BASE5, 10BASE2, 10BASE-T / 100BASE-TX / 1000BASE-TX
+  \end{itemize}
 \item
-  802.11a/b/g/n PHY
+  Wi-Fi
+
+  \begin{itemize}
+  \tightlist
+  \item
+    802.11a/b/g/n
+  \end{itemize}
 \item
   RS-232
 \end{itemize}
@@ -354,25 +630,8 @@ The signaling does not specify any max data rate, very high rates
 
 \end{frame}
 
-\begin{frame}{Layer 2: Data Link Layer}
-\protect\hypertarget{layer-2-data-link-layer}{}
-
-\begin{itemize}
-\tightlist
-\item
-  Ethernet
-\item
-  WiFi
-\item
-  Bluetooth
-\item
-  Token Ring
-\end{itemize}
-
-\end{frame}
-
-\begin{frame}{Layer 3: Network Layer}
-\protect\hypertarget{layer-3-network-layer}{}
+\begin{frame}{Internet}
+\protect\hypertarget{internet}{}
 
 \begin{itemize}
 \tightlist
@@ -380,14 +639,12 @@ The signaling does not specify any max data rate, very high rates
   IP
 \item
   ICMP
-\item
-  IPX
 \end{itemize}
 
 \end{frame}
 
-\begin{frame}{Layer 4: Transport Layer}
-\protect\hypertarget{layer-4-transport-layer}{}
+\begin{frame}{Transport}
+\protect\hypertarget{transport}{}
 
 \begin{itemize}
 \tightlist
@@ -395,36 +652,14 @@ The signaling does not specify any max data rate, very high rates
   TCP
 \item
   UDP
-\end{itemize}
-
-\end{frame}
-
-\begin{frame}{Layer 5: Session Layer}
-\protect\hypertarget{layer-5-session-layer}{}
-
-\begin{itemize}
-\tightlist
 \item
-  “sockets”
+  SCTP
 \item
-  NetBIOS
+  QUIC
 \end{itemize}
 
 \end{frame}
 
-\begin{frame}{Layer 6: Presentation Layer}
-\protect\hypertarget{layer-6-presentation-layer}{}
-
-\begin{itemize}
-\tightlist
-\item
-  SSL
-\end{itemize}
-
-\note{This layer is not really much used in the IP stack}
-
-\end{frame}
-
 \begin{frame}{Layer 7: Application Layer}
 \protect\hypertarget{layer-7-application-layer}{}
 
@@ -541,252 +776,6 @@ every node/.style={font=\bfseries}
 
 \end{frame}
 
-\hypertarget{lecture-esp8266}{%
-\section{Lecture: ESP8266}\label{lecture-esp8266}}
-
-\begin{frame}{NodeMCU hardware}
-\protect\hypertarget{nodemcu-hardware}{}
-
-\includegraphics{images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg}
-
-\end{frame}
-
-\begin{frame}{NodeMCU hardware}
-\protect\hypertarget{nodemcu-hardware-1}{}
-
-\begin{center}
-\begin{tikzpicture}
-
-\path
-    (0, 0) node(flash)[draw, rectangle,
-    minimum height=1cm, minimum width=2cm] {Flash}
-
-    (0, 1.5) node(esp8266)[draw, rectangle,
-    minimum height=1cm, minimum width=2cm] {ESP8266}
-
-    (3.5, 1.5) node(cp201x)[draw, rectangle,
-    minimum height=0.75cm, minimum width=1cm]
-    {CP201x}
-
-    (5.5, 1.5) node(usb)[]
-    {USB}
-;
-
-\draw[-] (esp8266) -- node[node font=\footnotesize, right]{QSPI} (flash);
-\draw[-] (esp8266) -- node[node font=\footnotesize, above]{UART} (cp201x) -- (usb);
-
-\node[rectangle, draw, fit=(esp8266) (flash), inner sep=2 mm,
-    label={[name=esp12_label,anchor=south]ESP-12}]
-    (esp12){};
-
-\node[rectangle, draw, thick, fit=(esp12_label) (esp12) (cp201x), inner sep=3 mm,
-    label={[anchor=north]south:NodeMCU}]
-    (nodemcu){};
-
-\end{tikzpicture}
-
-\end{center}
-
-\end{frame}
-
-\begin{frame}{ESP8266 software layers}
-\protect\hypertarget{esp8266-software-layers}{}
-
-\begin{center}
-\begin{tikzpicture}
-
-\node (rect_hw) [rectangle, draw, anchor=south west,
-    minimum width=6 cm, minimum height=1 cm,
-    label={[anchor=south]center:ESP8266 Hardware}] at (0, 0) {};
-
-\draw[thick] (-0.5, 1.25) -- (6.5, 1.25) ;
-
-\node  [rectangle, draw, anchor=south west,
-    minimum width=4 cm, minimum height=1 cm,
-    label={[anchor=south]center:ESP SDK}] at (0, 1.5) {};
-
-\node [rectangle, draw, anchor=south west,
-    minimum width=2 cm, minimum height=1 cm,
-    label={[align=center, text width=1cm]center:GCC  libc}] at (4, 1.5) {};
-
-\node [rectangle, draw, anchor=south west,
-    minimum width=6 cm, minimum height=1 cm,
-    label={[anchor=south]center:ESP interface}] at (0, 2.5) {};
-
-\node [rectangle, draw, anchor=south west,
-    minimum width=2 cm, minimum height=1 cm,
-    label={[align=center, text width= 2cm]center:Generic Arduino}] at (0, 3.5) {};
-
-\node [rectangle, draw, anchor=south west,
-    minimum width=2 cm, minimum height=1 cm,
-    label={[align=center, text width= 2cm]center:Ethernet}] at (2, 3.5) {};
-
-\node [rectangle, draw, anchor=south west,
-    minimum width=2 cm, minimum height=1 cm,
-    label={[align=center, text width= 2cm]center:ESP APIs}] at (4, 3.5) {};
-
-\draw [decorate, decoration={brace,amplitude=5pt, raise=-4pt}] (-0.5,2.5) -- (-0.5,4.5) node [black,midway,rotate=90, above] {Arduino};
-
-
-\end{tikzpicture}
-
-\end{center}
-
-\end{frame}
-
-\begin{frame}{ESP8266 + Arduino}
-\protect\hypertarget{esp8266-arduino}{}
-
-\begin{itemize}
-\tightlist
-\item
-  Standard Arduino IDE
-\item
-  ESP8266 Arduino core
-
-  \begin{itemize}
-  \tightlist
-  \item
-    https://github.com/esp8266/Arduino
-  \end{itemize}
-\end{itemize}
-
-\end{frame}
-
-\begin{frame}{Arduino IDE}
-\protect\hypertarget{arduino-ide}{}
-
-\includegraphics{images/arduino-ide.png}
-
-\end{frame}
-
-\begin{frame}[fragile]{Arduino code structure}
-\protect\hypertarget{arduino-code-structure}{}
-
-\begin{Shaded}
-\begin{Highlighting}[]
-\DataTypeTok{void}\NormalTok{ setup() \{}
-    \CommentTok{// Called once}
-\NormalTok{\}}
-
-\DataTypeTok{void}\NormalTok{ loop() \{}
-    \CommentTok{// Called repeatedly}
-\NormalTok{\}}
-\end{Highlighting}
-\end{Shaded}
-
-\note{MCU programming is often structured into:
-
-\begin{itemize}
-\tightlist
-\item
-  Configure
-
-  \begin{itemize}
-  \tightlist
-  \item
-    CPU
-  \item
-    GPIO ports
-  \item
-    MCU’s peripherals
-  \item
-    The rest of the board
-  \item
-    Configure application and callbacks.
-  \end{itemize}
-\item
-  Sleep
-\end{itemize}
-
-Arduino chooses to run the cpu at 100\% instead of the sleep step..}
-
-\end{frame}
-
-\begin{frame}[fragile]{Arduino file structure}
-\protect\hypertarget{arduino-file-structure}{}
-
-\begin{verbatim}
-foo/
-  foo.ino
-  config.h
-\end{verbatim}
-
-\note{\texttt{foo.ino} must always be in a \texttt{foo} directory.
-
-config.h is created by “new tab”.}
-
-\end{frame}
-
-\begin{frame}[fragile]{Generic Arduino APIs}
-\protect\hypertarget{generic-arduino-apis}{}
-
-\begin{Shaded}
-\begin{Highlighting}[]
-\CommentTok{// Pin: D0, D1, etc.}
-\CommentTok{// Mode: OUTPUT, INPUT, INPUT_PULLUP}
-\DataTypeTok{void}\NormalTok{ pinMode(}\DataTypeTok{uint8_t}\NormalTok{ pin, }\DataTypeTok{uint8_t}\NormalTok{ mode);}
-
-\CommentTok{// State: HIGH, LOW, true/false, 1/0}
-\DataTypeTok{void}\NormalTok{ digitalWrite(}\DataTypeTok{uint8_t}\NormalTok{ pin, }\DataTypeTok{uint8_t}\NormalTok{ state);}
-\DataTypeTok{int}\NormalTok{ digitalRead(}\DataTypeTok{uint8_t}\NormalTok{ pin);}
-
-\DataTypeTok{unsigned} \DataTypeTok{long}\NormalTok{ now millis();}
-\DataTypeTok{unsigned} \DataTypeTok{long}\NormalTok{ now micros();}
-\end{Highlighting}
-\end{Shaded}
-
-\end{frame}
-
-\begin{frame}[fragile]{ESP Arduino APIs}
-\protect\hypertarget{esp-arduino-apis}{}
-
-\begin{Shaded}
-\begin{Highlighting}[]
-\KeywordTok{class}\NormalTok{ \{}
-    \DataTypeTok{void}\NormalTok{ restart();}
-    \DataTypeTok{uint32_t}\NormalTok{ getFreeHeap();}
-    \DataTypeTok{uint32_t}\NormalTok{ getChipId();}
-
-\NormalTok{    ...}
-\NormalTok{\} ESP;}
-
-\CommentTok{// Usage}
-\NormalTok{ESP.restart();}
-\end{Highlighting}
-\end{Shaded}
-
-\end{frame}
-
-\begin{frame}[fragile]{ESP Arduino APIs}
-\protect\hypertarget{esp-arduino-apis-1}{}
-
-\begin{Shaded}
-\begin{Highlighting}[]
-\KeywordTok{class}\NormalTok{ \{}
-\NormalTok{    String macAddress();}
-
-    \DataTypeTok{wl_status_t}\NormalTok{ status();}
-    \DataTypeTok{int32_t}\NormalTok{ RSSI();}
-
-\NormalTok{    IPAddress localIP();}
-\NormalTok{    IPAddress subnetMask();}
-\NormalTok{    IPAddress gatewayIP();}
-\NormalTok{    IPAddress dnsIP(}\DataTypeTok{uint8_t}\NormalTok{ dns_no = }\DecValTok{0}\NormalTok{);}
-
-\NormalTok{    ...}
-\NormalTok{\} WiFi;}
-
-\CommentTok{// Usage:}
-
-\NormalTok{Serial.println(WiFi.localIP().toString());}
-\end{Highlighting}
-\end{Shaded}
-
-\note{http://arduino-esp8266.readthedocs.io/en/latest/libraries.html}
-
-\end{frame}
-
 \hypertarget{lecture-mqtt}{%
 \section{Lecture: MQTT}\label{lecture-mqtt}}
 
diff --git a/slides/what-is-iot-text.pdf b/slides/what-is-iot-text.pdf
index 2508346..7b5a4cb 100644
--- a/slides/what-is-iot-text.pdf
+++ b/slides/what-is-iot-text.pdf
diff --git a/slides/what-is-iot.md b/slides/what-is-iot.md
index db78358..b0f3762 100644
--- a/slides/what-is-iot.md
+++ b/slides/what-is-iot.md
@@ -15,6 +15,144 @@ header-includes:
 
 ---
 
+# NodeMCU
+
+!comment(aka NodeMCU aka ESP-12)
+
+## NodeMCU hardware
+
+!ifndef(QUICK)(
+![](images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg)
+)
+
+## NodeMCU hardware
+
+!ifndef(QUICK)(
+\begin{center}
+!include(images/nodemcu.pgf)
+\end{center}
+)
+
+## ESP8266 software layers
+
+!ifndef(QUICK)(
+\begin{center}
+!include(images/esp+arduino-sdks.pgf)
+\end{center}
+)
+
+## ESP8266 + Arduino
+
+* Standard Arduino IDE
+* ESP8266 Arduino core
+    * https://github.com/esp8266/Arduino
+
+## Arduino IDE
+
+!ifndef(QUICK)(
+![](images/arduino-ide.png)
+)
+
+## Arduino code structure
+
+~~~ .c++
+void setup() {
+    // Called once
+}
+
+void loop() {
+    // Called repeatedly
+}
+~~~
+
+::: notes
+
+MCU programming is often structured into:
+
+* Configure
+    * CPU
+    * GPIO ports
+    * MCU's peripherals
+    * The rest of the board
+    * Configure application and callbacks.
+* Sleep
+
+Arduino chooses to run the cpu at 100% instead of the sleep step..
+
+:::
+
+## Arduino file structure
+
+    foo/
+      foo.ino
+      config.h
+
+::: notes
+
+`foo.ino` must always be in a `foo` directory.
+
+config.h is created by "new tab".
+
+:::
+
+## Generic Arduino APIs
+
+~~~c++
+// Pin: D0, D1, etc.
+// Mode: OUTPUT, INPUT, INPUT_PULLUP
+void pinMode(uint8_t pin, uint8_t mode);
+
+// State: HIGH, LOW, true/false, 1/0
+void digitalWrite(uint8_t pin, uint8_t state);
+int digitalRead(uint8_t pin);
+
+unsigned long now millis();
+unsigned long now micros();
+~~~
+
+## ESP Arduino APIs
+
+~~~c++
+class {
+    void restart();
+    uint32_t getFreeHeap();
+    uint32_t getChipId();
+
+    ...
+} ESP;
+
+// Usage
+ESP.restart();
+~~~
+
+## ESP Arduino APIs
+
+~~~c++
+class {
+    String macAddress();
+
+    wl_status_t status();
+    int32_t RSSI();
+
+    IPAddress localIP();
+    IPAddress subnetMask();
+    IPAddress gatewayIP();
+    IPAddress dnsIP(uint8_t dns_no = 0);
+
+    ...
+} WiFi;
+
+// Usage:
+
+Serial.println(WiFi.localIP().toString());
+~~~
+
+::: notes
+
+http://arduino-esp8266.readthedocs.io/en/latest/libraries.html
+
+:::
+
 # What is IoT
 
 ## What is IoT
@@ -179,31 +317,28 @@ Datasheet page 18
 
 ## What is the internet again?
 
-## OSI model
-
-1. Physical Layer
-1. Data Link Layer
-1. Network Layer
-1. Transport Layer
-1. Session Layer
-1. Presentation Layer
-1. Application Layer
+## TCP/IP Layers
 
+!ifndef(QUICK)(
+\begin{center}
+!include(images/tcpip.pgf)
+\end{center}
+)
 
-* [Wikipedia: OSI model](https://en.wikipedia.org/wiki/OSI_model)
-* [Wikipedia: OSI model#Examples](https://en.wikipedia.org/wiki/OSI_model#Examples)
-
-::: notes
-
-Does not match the TCP/IP stack very closely.
+## Packet encapsulation
 
-:::
+!ifndef(QUICK)(
+\begin{center}
+!include(images/ip-encapsulation.pgf)
+\end{center}
+)
 
-## Layer 1: Physical Layer
+## Network interface
 
-* 10BASE5, 10BASE2
-* 10BASE-T / 100BASE-TX / 1000BASE-TX
-* 802.11a/b/g/n PHY
+* Ethernet
+    * 10BASE5, 10BASE2, 10BASE-T / 100BASE-TX / 1000BASE-TX
+* Wi-Fi
+    * 802.11a/b/g/n
 * RS-232
 
 ::: notes
@@ -222,39 +357,17 @@ levels. The signaling does not specify any max data rate, very high rates
 
 :::
 
-
-## Layer 2: Data Link Layer
-
-* Ethernet
-* WiFi
-* Bluetooth
-* Token Ring
-
-## Layer 3: Network Layer
+## Internet
 
 * IP
 * ICMP
-* IPX
 
-## Layer 4: Transport Layer
+## Transport
 
 * TCP
 * UDP
-
-## Layer 5: Session Layer
-
-* "sockets"
-* NetBIOS
-
-## Layer 6: Presentation Layer
-
-* SSL
-
-::: notes
-
-This layer is not really much used in the IP stack
-
-:::
+* SCTP
+* QUIC
 
 ## Layer 7: Application Layer
 
@@ -300,144 +413,6 @@ Note that the "total length" field is 16 bits, 2 bytes, it's maximum value is 64
 \end{center}
 )
 
-# Lecture: ESP8266
-
-!comment(aka NodeMCU aka ESP-12)
-
-## NodeMCU hardware
-
-!ifndef(QUICK)(
-![](images/NodeMCU-–-Board-de-desarrollo-con-módulo-ESP8266-WiFi-y-Lua-4.jpg)
-)
-
-## NodeMCU hardware
-
-!ifndef(QUICK)(
-\begin{center}
-!include(images/nodemcu.pgf)
-\end{center}
-)
-
-## ESP8266 software layers
-
-!ifndef(QUICK)(
-\begin{center}
-!include(images/esp+arduino-sdks.pgf)
-\end{center}
-)
-
-## ESP8266 + Arduino
-
-* Standard Arduino IDE
-* ESP8266 Arduino core
-    * https://github.com/esp8266/Arduino
-
-## Arduino IDE
-
-!ifndef(QUICK)(
-![](images/arduino-ide.png)
-)
-
-## Arduino code structure
-
-~~~ .c++
-void setup() {
-    // Called once
-}
-
-void loop() {
-    // Called repeatedly
-}
-~~~
-
-::: notes
-
-MCU programming is often structured into:
-
-* Configure
-    * CPU
-    * GPIO ports
-    * MCU's peripherals
-    * The rest of the board
-    * Configure application and callbacks.
-* Sleep
-
-Arduino chooses to run the cpu at 100% instead of the sleep step..
-
-:::
-
-## Arduino file structure
-
-    foo/
-      foo.ino
-      config.h
-
-::: notes
-
-`foo.ino` must always be in a `foo` directory.
-
-config.h is created by "new tab".
-
-:::
-
-## Generic Arduino APIs
-
-~~~c++
-// Pin: D0, D1, etc.
-// Mode: OUTPUT, INPUT, INPUT_PULLUP
-void pinMode(uint8_t pin, uint8_t mode);
-
-// State: HIGH, LOW, true/false, 1/0
-void digitalWrite(uint8_t pin, uint8_t state);
-int digitalRead(uint8_t pin);
-
-unsigned long now millis();
-unsigned long now micros();
-~~~
-
-## ESP Arduino APIs
-
-~~~c++
-class {
-    void restart();
-    uint32_t getFreeHeap();
-    uint32_t getChipId();
-
-    ...
-} ESP;
-
-// Usage
-ESP.restart();
-~~~
-
-## ESP Arduino APIs
-
-~~~c++
-class {
-    String macAddress();
-
-    wl_status_t status();
-    int32_t RSSI();
-
-    IPAddress localIP();
-    IPAddress subnetMask();
-    IPAddress gatewayIP();
-    IPAddress dnsIP(uint8_t dns_no = 0);
-
-    ...
-} WiFi;
-
-// Usage:
-
-Serial.println(WiFi.localIP().toString());
-~~~
-
-::: notes
-
-http://arduino-esp8266.readthedocs.io/en/latest/libraries.html
-
-:::
-
 # Lecture: MQTT
 
 ## MQTT