Content update (RGB section)

Author: canchebagur

content/hardware/03.nano/boards/nano-r4/tutorials/01.user-manual/assets/front_page.png renamed to content/hardware/03.nano/boards/nano-r4/tutorials/01.user-manual/assets/front-page.png

@@ -40,7 +40,7 @@ This user manual provides a comprehensive overview of the Nano R4 board, highlig
 
 The Nano R4 board represents the natural evolution of the Nano family, combining the powerful RA4M1 microcontroller from Renesas with the compact and familiar Nano form factor. This board is designed to facilitate seamless transition from prototyping to production, using the same powerful core already used in the UNO R4 family.
 
-![ ](assets/front_page.png)
+![ ](assets/front-page.png)
 
 The Nano R4 includes a high-performance 32-bit microcontroller (R7FA4M1AB3CFM), expanded connectivity through an onboard Qwicc connector and advanced features such as DAC, CAN and operational amplifiers. Its compact dimensions (18 mm x 45 mm) and robust construction make the Nano R4 board an excellent choice for projects that demand sensor fusion capabilities and the computational power of modern microcontrollers.
 
@@ -88,6 +88,8 @@ The Arduino UNO R4 Boards core provides support for the following:
 
 ### Pinout
 
+![Nano R4 pinout](assets/simple-pinout.png)
+
 The full pinout is available and downloadable as PDF from the link below:
 
 - Nano R4 pinout
@@ -129,26 +131,38 @@ The Nano R4 can be connected to your computer very simply using its onboard USB-
 
 ***<strong>Important note:</strong> The Nano R4 operates at +5 VDC natively. When connecting sensors or modules that operate at +3.3 VDC, make sure to verify voltage compatibility to avoid component damage.***
 
-### Powering the Board
+  ### Powering the Board
+
+  The Nano R4 can be powered in several ways:
+
+  - **Via USB-C connector**: The most common method during development and programming
+  - **Via `VIN` pin**: Using an external +6-21 VDC power supply that will be internally regulated to +5 VDC
+  - **Via `5V` pin**: Directly connecting a regulated +5 VDC source (with caution)
+
+  ![Different ways to power the Nano R4 board](assets/user-manual-4.png)
+
+  ***<strong>Important note:</strong> The Nano R4's `VIN` pin accepts a voltage range of +6-21 VDC. Do not connect voltages outside this range as you could permanently damage the board. Always verify all the connections before applying power.***
 
-The Nano R4 can be powered in several ways:
+  #### Internal +3.3 VDC Power Supply
 
-- **Via USB-C connector**: The most common method during development and programming
-- **Via `VIN` pin**: Using an external +6-21 VDC power supply that will be internally regulated to +5 VDC
-- **Via `5V` pin**: Directly connecting a regulated +5 VDC source (with caution)
+  The Nano R4 also includes an onboard +3.3 VDC regulator ([AP2112K](https://www.diodes.com/assets/Datasheets/AP2112.pdf)) that provides power for the following:
 
-![Different ways to power the Nano R4 board](assets/user-manual-4.png)
+  - **Qwicc connector**: Supplies +3.3 VDC power to connected I²C devices
+  - **I²C level translation**: Enables communication between the +5 VDC microcontroller and +3.3 VDC Qwicc devices
+  - **Internal +3.3 VDC peripherals**: Powers certain internal circuits that require +3.3 VDC operation
 
-***<strong>Important note:</strong> The Nano R4's `VIN` pin accepts a voltage range of +6-21 VDC. Do not connect voltages outside this range as you could permanently damage the board. Always verify all the connections before applying power.***
+  This internal +3.3 VDC supply allows the board to interface with both +5 VDC and +3.3 VDC devices through the Qwicc ecosystem while maintaining the +5 VDC operation of the board's main microcontroller.
 
-The Nano R4 also includes an onboard +3.3 VDC regulator ([AP2112K](https://www.diodes.com/assets/Datasheets/AP2112.pdf)) that provides power for the following:
+  #### VBATT Pin
 
-- **Qwicc connector**: Supplies +3.3 VDC power to connected I²C devices
-- **I²C level translation**: Enables communication between the +5 VDC microcontroller and +3.3 VDC Qwicc devices
-- **Internal +3.3 VDC peripherals**: Powers certain internal circuits that require +3.3 VDC operation
+  The `VBATT` pin allows the connection of a backup battery (within the +1.6-3.6 VDC range) to maintain the microcontroller's real-time clock (RTC) and certain low-power functions when the main power source is disconnected from the board. This is particularly useful for applications that need to keep track of time or maintain certain settings of the microcontroller during power outages. 
 
-This internal +3.3 VDC supply allows the board to interface seamlessly with both +5 VDC and +3.3 VDC devices through the Qwicc ecosystem while maintaining the +5 VDC operation of the board's main microcontroller.
+  Common battery options for this purpose include the following:
 
+  - Coin cell batteries (CR2032: +3 VDC)
+  - Rechargeable LiPo batteries (+3.7 VDC nominal)
+  - AA/AAA batteries (+1.5-3 VDC depending on the chemistry of the battery)
+    
 ### Hello World Example
 
 Let's program the Nano R4 to reproduce the classic `Hello World` example used in the Arduino ecosystem: the `Blink` sketch. We will use this example to verify that the Nano R4's connection to the computer works correctly, that the Arduino IDE is properly configured, and that both the board and development environment function as expected.
@@ -197,11 +211,11 @@ To upload the sketch to the board, click the **Verify** button to compile the sk
 
 ![Uploading a sketch to the Nano R4 in the Arduino IDE](assets/user-manual-5.png)
 
-As shown in the image above, you should see the built-in orange user LED of your Nano R4 board turn on for one second, then turn off for one second, repeating this cycle continuously. 
+As shown in the animation below, you should see the built-in orange user LED of your Nano R4 board turn on for one second, then turn off for one second, repeating this cycle continuously. 
 
 ![Onboard orange user LED blinking](assets/user-manual-6.gif)
 
-Additionally, you can open the Arduino IDE's Serial Monitor (Tools > Serial Monitor) to see the status messages that the sketch sends each time the LED state changes.
+Additionally, you can open the Arduino IDE's Serial Monitor (Tools > Serial Monitor) to see the status messages that the example sketch sends each time the LED state changes.
 
 ![Arduino IDE Serial Monitor output for the Blink sketch](assets/user-manual-7.png)
 
@@ -213,4 +227,93 @@ This example confirms the following:
 - USB communication is working
 - Digital pins respond to commands
 
-Congratulations! You have successfully completed your first program on the Nano R4 board. You are now ready to explore the more advanced features of this tiny but powerful board.
+Congratulations! You have successfully completed your first program on the Nano R4 board. You are now ready to explore the more advanced features of this tiny but powerful board.
+
+## LEDs
+
+This user manual section covers the Nano R4 built-in LEDs, showing their main hardware and software characteristics.
+
+### RGB LED
+
+The Nano R4 features a built-in RGB LED that can be used as a visual feedback indicator for the user.
+
+![Built-in RGB LED of the Nano R4 board](assets/user-manual-8.png)
+
+The built-in RGB LED can be accessed through the following macro definitions:
+
+| **Built-in LED** | **Macro Definition** | **Microcontroller Pin** |
+|:----------------:|:--------------------:|:-----------------------:|
+|      Red LED     |        `LEDR`        |          `P409`         |
+|     Green LED    |        `LEDG`        |          `P411`         |
+|     Blue LED     |        `LEDB`        |          `P410`         |
+
+***The built-in RGB LED on the Nano R4 must be pulled to ground (GND) to make it light up. This means that a voltage level of `LOW` on each of their pins will turn the specific color of the LED on, and a voltage level of `HIGH` will turn them off.***
+
+The following example sketch each of the RGB LED colors at an interval of 500 ms:
+
+```arduino
+/**
+RGB LED Example for the Arduino Nano R4 Board
+Name: nano_r4_rgb_led.ino
+Purpose: This sketch demonstrates how to control the built-in
+RGB LED of the Arduino Nano R4 board.
+
+@author Arduino Product Experience Team
+@version 1.0 01/06/25
+*/
+
+void setup() {
+  // Initialize serial communication at 115200 baud
+  Serial.begin(115200);
+  
+  // Initialize LEDR, LEDG and LEDB as outputs
+  pinMode(LEDR, OUTPUT);
+  pinMode(LEDG, OUTPUT);
+  pinMode(LEDB, OUTPUT);
+  
+  // Turn off all LEDs initially
+  digitalWrite(LEDR, HIGH);
+  digitalWrite(LEDG, HIGH);
+  digitalWrite(LEDB, HIGH);
+  
+  Serial.println("- Arduino Nano R4 - RGB LED Example started...");
+}
+
+void loop() {
+  // Turn on the built-in red LED and turn off the rest
+  digitalWrite(LEDR, LOW);
+  digitalWrite(LEDG, HIGH);
+  digitalWrite(LEDB, HIGH);
+  Serial.println("- Red LED on!");
+  delay(500);
+  
+  // Turn on the built-in green LED and turn off the rest
+  digitalWrite(LEDR, HIGH);
+  digitalWrite(LEDG, LOW);
+  digitalWrite(LEDB, HIGH);
+  Serial.println("- Green LED on!");
+  delay(500);
+  
+  // Turn on the built-in blue LED and turn off the rest
+  digitalWrite(LEDR, HIGH);
+  digitalWrite(LEDG, HIGH);
+  digitalWrite(LEDB, LOW);
+  Serial.println("- Blue LED on!");
+  delay(500);
+  
+  // Turn off all LEDs
+  digitalWrite(LEDR, HIGH);
+  digitalWrite(LEDG, HIGH);
+  digitalWrite(LEDB, HIGH);
+  Serial.println("- All LEDs off!");
+  delay(500);
+}
+```
+
+You should now see the built-in RGB LED cycling through red, green, and blue colors, followed by a brief moment with all LEDs off, repeating this pattern continuously.
+
+![Onboard RGB user LED blinking](assets/user-manual-9.gif)
+
+Additionally, you can open the Arduino IDE's Serial Monitor (Tools > Serial Monitor) to see the status messages that the example sketch sends each time the RGB LEDs state changes.
+
+![Arduino IDE Serial Monitor output for the RGB LED example sketch](assets/user-manual-10.png)