update certificates and minor changes

Author: Hannes7eicher

content/hardware/03.nano/boards/nano-r4/certifications/Arduino_ABX00142-CERT_CE_EMC.pdf

@@ -6,22 +6,41 @@ The Arduino Nano R4 features the powerful Renesas RA4M1 microcontroller with a 3
 
 <Feature title="Qwiic I²C Connector" image="communication">
 Easily connect sensors and peripherals using the onboard Qwiic connector, which enables plug-and-play I²C communication at 3.3 V logic levels while interfacing with the 5 V system.
+<FeatureWrapper>
+  <FeatureLink title="Documentation" url="/tutorials/nano-r4/user-manual/#ic-communication"/>
+</FeatureWrapper>
 </Feature>
 
-<Feature title="Built-in DAC & OPAMP" image="mcu">
-With a 12-bit DAC on the A0 pin and an integrated operational amplifier, the Nano R4 enables analog signal generation and advanced signal conditioning.
+<Feature title="Operational Amplifier (OPAMP)" image="mcu">
+The Nano R4 board features a built-in operational amplifier (OPAMP) that provides signal conditioning and amplification capabilities
+<FeatureWrapper>
+  <FeatureLink title="Documentation" url="/tutorials/nano-r4/user-manual/#operational-amplifier-opamp"/>
+</FeatureWrapper>
+</Feature>
+
+<Feature title="Digital-to-Analog Converter (DAC)" image="mcu">
+Use the onboard 12-bit DAC to build sophisticated audio projects.
+<FeatureWrapper>
+  <FeatureLink title="Documentation" url="/tutorials/nano-r4/user-manual/#digital-to-analog-converter-dac"/>
+</FeatureWrapper>
 </Feature>
 
 <Feature title="USB-C®" image="usb">
 The Nano R4 features a USB-C® connector for streamlined power and data transfer.
 </Feature>
 
 <Feature title="CAN Bus Support" image="communication">
-The Nano R4 supports CAN communication (with external transceivers), making it suitable for industrial and automotive applications.
+The Nano R4 supports CAN communication, making it suitable for industrial and automotive applications. This requires an external transceiver.
+<FeatureWrapper>
+  <FeatureLink title="Documentation" url="/tutorials/nano-r4/user-manual/#can-communication"/>
+</FeatureWrapper>
 </Feature>
 
-<Feature title="Real-Time Clock (RTC)" image="clock">
-The built-in RTC and 16 MHz external crystal ensure accurate timekeeping, making it ideal for data logging and scheduled task applications.
+<Feature title="Real-Time Clock (RTC)" image="mcu">
+Keep track of time & date and set alarms with the built-in RTC.
+<FeatureWrapper>
+  <FeatureLink title="Documentation" url="/tutorials/nano-r4/user-manual/#real-time-clock-rtc"/>
+</FeatureWrapper>
 </Feature>
 
 <Feature title="5 V Operating Voltage" image="power">

content/hardware/03.nano/boards/nano-r4/certifications/Arduino_ABX00142-CERT_RCM.pdf

@@ -7,12 +7,14 @@ USB:
 Pins:
   Digital I/O Pins: 21 (all the exposed I/O can be used as digital I/O pins)
   Analog input pins: 8
-  DAC: 1
+  DAC: 1 (A0)
+  OPAMP: A1, A2, A3
+  VBAT: J5
   PWM pins: 6
   External interrupts: 2,3
 Communication:
   UART: 1
-  I2C: 2
+  I2C: "2 (5 V: A4, A5 / 3.3 V: QWIIC, J3, J4)"
   SPI: 1
   CAN: 1
 Power: