code tested, missing tex on solving tty

Readme.md

@@ -0,0 +1,118 @@
+# Testing the ESP32 and Arduino IDE
+## Introduction
+This repository shows the basic usage of the Arduino IDE with the ESP32 development board by implementing a blinking LED and serial communication.
+
+# Programming the ESP32 Board
+For this example course, we are going to use the ESP32-S WROOM, **please check what board you are using**.
+![](./esp32swroom.jpg)
+
+then, we need to install the Arduino IDE to program the ESP32.
+
+## Installing the Arduino IDE
+
+The Arduino IDE can be installed on *Windows, MacOS, or GNU Linux*, the Windows and MacOS installation is commonly using the installer. In the case of the *GNU Linux* it is highly recommended to use the distribution's package manger. In my case, the ArchLinux manager is *pacman*, thus use:
+
+```
+sudo pacman -Sy arduino
+[sudo] password for gmarx:
+:: Synchronizing package databases...
+ core                                 157.9 KiB   235 KiB/s 00:01 [####################################] 100%
+ extra                               1710.6 KiB  3.66 MiB/s 00:00 [####################################] 100%
+ community                              6.7 MiB  7.49 MiB/s 00:01 [####################################] 100%
+warning: arduino-1:1.8.19-1 is up to date -- reinstalling
+resolving dependencies...
+looking for conflicting packages...
+
+Packages (1) arduino-1:1.8.19-1
+
+Total Installed Size:  59.36 MiB
+Net Upgrade Size:       0.00 MiB
+
+:: Proceed with installation? [Y/n]
+```
+
+**Note: The Arduino IDE requires Java jdk8 and jre8 installed on the OS.**
+
+**Note: You can install a Dark theme by [following these instructions]()**
+
+## Adding the ESP32 Boards
+The addition of the ESP32 boards requires to include a URL to download a *Board Manager* by clicking on `File -> Preferences` and pasting the URL `https://dl.espressif.com/dl/package_esp32_index.json` in the field *Additional Boards Manager URLs*:
+
+```
+https://dl.espressif.com/dl/package_esp32_index.json
+```
+![](./board.png)
+
+Next, we can install the ESP32 board on Arduino IDE by `Tools -> Board -> Boards Manager ...`, and writte `ESP32` to install the tools required to work with:
+
+![](./install-board.png)
+
+# Sample code to test ESP32
+Before start programming the ESP32 board we have to select the proper board in the `Board` tool. Thus, again open and select the `Tools -> Bord -> DOIT ESP32 DEVKIT V1`. Then, paste the next code segtion to test the ESP32 board; the code is also the `blinking-serial.ino`file:
+
+```
+  /*
+ *
+ * Example code for ESP32-S:
+ * The code blinks the onboard LED (at D2 in GPIO 02) every 0.500 seconds.
+ * The code also prints by serial communcation the word "Hello" during the
+ * ON stage of the LED, and then prints "World" during the OFF.
+ * Gerardo Marx 19/Jul/2022
+ */
+
+// this variable is defined in pins_arduino.h for DOIT ESP32 DEVKIT V1
+// int LED_BUILTIN = 02;
+int LED_ONBOARD = 02;
+
+void setup() {
+  // put your setup code here, to run once:
+  pinMode(LED_BUILTIN, OUTPUT);
+  //serial  monitor setup
+  Serial.begin(115200);
+      }
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  Serial.print("ON");
+  digitalWrite(LED_BUILTIN, HIGH);
+  delay(500);
+  // after delay
+  Serial.print(" - OFF\n");
+  digitalWrite(LED_BUILTIN, LOW);
+  delay(500);
+
+```
+next, press `Crt-u` to compile and upload the code generated into the board.
+
+## The error `no module named serial`
+If you get an error like this:
+```
+ModuleNotFoundError: No module named 'serial'
+exit status 1
+Error compiling for board DOIT ESP32 DEVKIT V1.
+```
+
+then, it is necessary to install in python:
+```
+pip3 install pyserial
+```
+and must probably you will requiere pip3 python package manager:
+```
+sudo pacman -Sy python-pip
+```
+## `Permission denied: '/dev/ttyUSB0'`
+
+```
+ls -l /dev/ttyUSB0
+crw-rw---- 1 root uucp 188, 0 Aug  7 14:50 /dev/ttyUSB0
+```
+
+```
+sudo usermod -a -G uucp $USER
+groups
+libvirt uucp gmarx
+```
+
+**Note: you need to relogin into you session.**
+
+

blinking-serial.ino

@@ -1,4 +1,4 @@
-/*
+  /*
  * 
  * Example code for ESP32-S:
  * The code blinks the onboard LED (at D2 in GPIO 02) every 0.500 seconds.
@@ -9,14 +9,13 @@
 
 // this variable is defined in pins_arduino.h for DOIT ESP32 DEVKIT V1
 // int LED_BUILTIN = 02; 
-int LED_ONBOARD = 02;
 
 void setup() {
   // put your setup code here, to run once:
   pinMode(LED_BUILTIN, OUTPUT);
   //serial  monitor setup
   Serial.begin(115200);
-}
+      }
 
 void loop() {
   // put your main code here, to run repeatedly: