Add assembly/wiring instructions and diagram

Author: flavioheleno

README.md

@@ -4,14 +4,10 @@ This project carries code samples for different types of displays and sensors, u
 
 ## Available Examples
 
-### Displays
-
-- [OLED: SSD1322 Driver](Displays/Ssd1322.php)
-
 ### Sensors
 
-- [HCSR04: Ultrasonic ranging sensor](Sensors/HcSr04.php)
+- [HC-SR04: Ultrasonic Distance Sensor](Sensors/HcSr04/)
 
 ## License
 
-This library is licensed under the [MIT License](LICENSE).
+This project is licensed under the [MIT License](LICENSE).

Sensors/HcSr04/HcSr04.fzz

@@ -4,7 +4,7 @@
 require_once __DIR__ . '/../vendor/autoload.php';
 
 /**
- * This example measures distance using the HC-SR04 Ultrassonic sensor.
+ * This example measures distance using the HC-SR04: Ultrasonic Distance Sensor.
  * Requires ext-gpio (https://github.com/embedded-php/ext-gpio) to be installed.
  *
  * Assembly instructions:

Sensors/HcSr04.php Sensors/HcSr04/HcSr04.php

@@ -0,0 +1,22 @@
+# HC-SR04: Ultrasonic Distance Sensor
+
+## Requirements
+
+The following libraries/extensions are required by this example:
+
+* [ext-gpio](https://github.com/embedded-php/ext-gpio)
+
+## Assembly
+
+The wiring instructions below are required to run this example *without* modification.
+
+HC-SR04 | Raspberry Pi | Reference
+--------|--------------|----------
+VCC     | Pin 02       | [5v Power](https://pinout.xyz/pinout/5v_power#)
+Trigger | Pin 22       | [GPIO 25](https://pinout.xyz/pinout/pin22_gpio25#)
+Echo    | Pin 18       | [GPIO 24](https://pinout.xyz/pinout/pin18_gpio24#)
+GND     | Pin 30       | [Ground](https://pinout.xyz/pinout/ground#)
+
+## Diagram
+
+![Wiring Diagram](HcSr04.png)