ARDUINO ABX00087 UNO R4 WiFi User Guide

ARDUINO ABX00087 UNO R4 WiFi

Product Information

Product Reference Manual SKU: ABX00087

Description: Target areas: Maker, beginner, education

Features:

• The R7FA4M1AB3CFM#AA0, often referred to as RA4M1 in this datasheet, is the main MCU on the UNO R4 WiFi, connected to all pin headers on the board as well as all communication buses.
• Memory: 256 kB Flash Memory, 32 kB SRAM, 8 kB Data Memory (EEPROM)
• Peripherals: Capacitive Touch Sensing Unit (CTSU), USB 2.0 Full-Speed Module (USBFS), 14-bit ADC, Up to 12-bit DAC,Operational Amplifier (OPAMP)
• Communication: 1x UART (pin D0, D1), 1x SPI (pin D10-D13, ICSP header), 1x I2C (pin A4, A5, SDA, SCL), 1x CAN (pin D4, D5,external transceiver is required)

For more technical details on the R7FA4M1AB3CFM#AA0 microcontroller, visit the R7FA4M1AB3CFM#AA0 datasheet.

The ESP32-S3-MINI-1-N8 features:

• This module acts as a secondary MCU on the UNO R4 WiFi and communicates with the RA4M1 MCU using a logic level translator.
• Note that this module operates on 3.3 V as opposed to the RA4M1’s 5 V operating voltage.

For more technical details on the ESP32-S3-MINI-1-N8 module, visit the ESP32-S3-MINI-1-N8datasheet.

Product Usage Instructions

Recommended Operating Conditions:

Functional Overview:

The operating voltage for the RA4M1 is fixed at 5 V to be hardware compatible with shields, accessories, and circuits based on previous Arduino UNO boards.

Board Topology:
Front View:

Ref. U1 U2 U3 U4 U5 U6 U_LEDMATRIX M1 PB1 JANALOG JDIGITAL JOFF J1 J2 J3 J5 J6 DL1

Top View:
Ref. DL2 LED RX (serial receive), DL3 LED Power (green), DL4 LED SCK (serial clock), D1 PMEG6020AELRX Schottky Diode, D2 PMEG6020AELRX Schottky Diode, D3 PRTR5V0U2X,215 ESD Protection

ESP Header:
The header located close to the RESET button can be used to access the ESP32-S3 module directly. The pins accessible are:

• ESP_IO42 – MTMS debugging (Pin 1)
• ESP_IO41 – MTDI debugging (Pin 2)
• ESP_TXD0 – Serial Transmit (UART) (Pin 3)
• ESP_DOWNLOAD – boot (Pin 4)
• ESP_RXD0 – Serial Receive (UART) (Pin 5)
• GND – ground (Pin 6)

Description
The Arduino® UNO R4 WiFi is the first UNO board to feature a 32-bit microcontroller and an ESP32-S3 Wi-Fi® module (ESP32-S3-MINI-1-N8). It features a RA4M1 series microcontroller from Renesas (R7FA4M1AB3CFM#AA0),based on a 48 MHz Arm® Cortex®-M4 microprocessor. The UNO R4 WiFi’s memory is larger than its predecessors,with 256 kB flash, 32 kB SRAM and 8 kB of EEPROM.
The RA4M1’s operating voltage is fixed at 5 V, whereas the ESP32-S3 module is 3.3 V. Communication between these two MCUs are performed via a logic level translator (TXB0108DQSR).

Target areas:
Maker, beginner, education

Features

The R7FA4M1AB3CFM#AA0, often referred to as RA4M1 in this datasheet, is the main MCU on the UNO R4 WiFi, connected to all pin headers on the board as well as all communication buses.

Overview

• 48 MHz Arm® Cortex®-M4 microprocessor with a floating point unit (FPU) 5 V operating voltage
• Real-time Clock (RTC)
• Memory Protection Unit (MPU)
• Digital-to-analog Converter (DAC)

Memory

• 256 kB Flash Memory
• 32 kB SRAM
• 8 kB Data Memory (EEPROM)

Peripherals

• Capacitive Touch Sensing Unit (CTSU)
• USB 2.0 Full-Speed Module (USBFS)
• 14-bit ADC
• Up to 12-bit DAC
• Operational Amplifier (OPAMP)

Power

• Operating voltage for RA4M1 is 5 V
• Recommended input voltage (VIN) is 6-24 V
• Barrel jack connected to VIN pin (6-24 V)
• Power via USB-C® at 5 V

Communication

• 1x UART (pin D0, D1)
• 1x SPI (pin D10-D13, ICSP header)
• 1x I2C (pin A4, A5, SDA, SCL)
• 1x CAN (pin D4, D5, external transceiver is required)

See the full datasheet for the R7FA4M1AB3CFM#AA0 in the link below:

• R7FA4M1AB3CFM#AA0 datasheet
  The ESP32-S3-MINI-1-N8 is the secondary MCU with a built-in antenna for Wi-Fi® & Bluetooth® connectivity. This module operates on 3.3 V and communicates with the RA4M1 using a logic level translator (TXB0108DQSR).

Overview

• Xtensa® dual-core 32-bit LX7 microprocessor
• 3.3 V operating voltage
• 40 MHz crystal oscillator

Wi-Fi®

• Wi-Fi® support with 802.11 b/g/n standard (Wi-Fi® 4)
• Bit rate at up to 150 Mbps
• 2.4 GHz band

Bluetooth®

• Bluetooth® 5

See the full datasheet for the ESP32-S3-MINI-1-N8 in the link below:

• ESP32-S3-MINI-1-N8 datasheet

The Board

Application Examples
The UNO R4 WiFi is part of the first UNO series of 32-bit development boards, being previously based on 8-bit AVR microcontrollers. There are thousands of guides, tutorials and books written about the UNO board, where the UNO R4 WiFi continues its legacy.
The board features 14 digital I/O ports, 6 analog channels, dedicated pins for I2C, SPI and UART connections. It has a significantly larger memory: 8 times more flash memory (256 kB) and 16 times more SRAM (32 kB). With a 48 MHz clock speed, it is also 3x faster than its predecessors.
In addition, it features an ESP32-S3 module for Wi-Fi® & Bluetooth® connectivity, as well as a built-in 12×8 LED matrix, making one of the most visually unique Arduino board to date. The LED matrix is fully programmable, where you can load anything from still frames to custom animations.
Entry-level projects: If this is your first project within coding and electronics, the UNO R4 WiFi is a good fit. It is easy to get started with, and it has a lot of online documentation.
Easy IoT applications: build projects without writing any networking code in the Arduino IoT Cloud. Monitor your board, connect it with other boards and services, and develop cool IoT projects.
LED Matrix: the 12×8 LED matrix on the board can be used for showing animations, text scrolling, create mini-games and much more, being the perfect feature to give your project more personality.

Related Products

• UNO R3
• UNO R3 SMD
• UNO R4 Minima

Rating

Recommended Operating Conditions

Note: VDD controls the logic level and is connected to the 5V power rail. VAREF is for the analog logic.

Functional Overview

Block Diagram

Board Topology

Front View

Microcontroller (R7FA4M1AB3CFM#AA0)

The UNO R4 WiFi is based on the 32-bit RA4M1 series microcontroller, R7FA4M1AB3CFM#AA0, from Renesas, which uses a 48 MHz Arm® Cortex®-M4 microprocessor with a floating point unit (FPU).
The operating voltage for the RA4M1 is fixed at 5 V as to be hardware compatible with shields, accessories & circuits based on previous Arduino UNO boards.

The R7FA4M1AB3CFM#AA0 features:

• 256 kB flash / 32 kB SRAM / 8 kB data flash (EEPROM)
• Real-time Clock (RTC)
• 4x Direct Memory Access Controller (DMAC)
• 14-bit ADC
• Up to 12-bit DAC
• OPAMP
• CAN bus

For more technical details on this microcontroller, visit the Renesas – RA4M1 series official documentation.

6 Wi-Fi® / Bluetooth® Module (ESP32-S3-MINI-1-N8)
The Wi-Fi® / Bluetooth® LE module on the UNO R4 WiFi is from the ESP32-S3 SoCs. It features the Xtensa® dual-core 32-bit LX7 MCU, a built-in antenna and support for 2.4 GHz bands.

The ESP32-S3-MINI-1-N8 features:

• Wi-Fi® 4 – 2.4 GHz band
• Bluetooth® 5 LE support
• 3.3 V operating voltage 384 kB ROM
• 512 kB SRAM
• Up to 150 Mbps bit rate

This module acts as a secondary MCU on the UNO R4 WiFi, and communicates with the RA4M1 MCU using a logic level translator. Note that this module operates on 3.3 V as opposed to the RA4M1’s 5 V operating voltage.

ESP Header

The header located close to the RESET button can be used to access the ESP32-S3 module directly. The pins accessible are:

• ESP_IO42 – MTMS debugging (Pin 1)
• ESP_IO41 – MTDI debugging (Pin 2)
• ESP_TXD0 – Serial Transmit (UART) (Pin 3)
• ESP_DOWNLOAD – boot (Pin 4)
• ESP_RXD0 – Serial Receive (UART) (Pin 5)
• GND – ground (Pin 6)

USB Bridge
When programming the UNO R4 WiFi, the RA4M1 MCU is programmed via the ESP32-S3 module by default. The U2 and U6 switches can switch the USB communication to go directly to the RA4M1 MCU, by writing a high state to the P408 pin (D40).

Soldering together the SJ1 pads permanently sets the USB communication directly to the RA4M1, bypassing the ESP32-S3.

USB Connector
The UNO R4 WiFi has one USB-C® port, used to power and program your board as well as sending & receiving serial communication.
Note: The board should not be powered with more than 5 V via the USB-C® port.

LED Matrix

The UNO R4 WiFi features a 12×8 matrix of red LEDs (U_LEDMATRIX), connected using the technique known as charlieplexing.

The following pins on the RA4M1 MCU are used for the matrix:

• P003
• P004
• P011
• P012
• P013
• P015
• P204
• P205
• P206
• P212
• P213

These LEDs can be accessed as an array, using a specific library. See the mapping below:

This matrix can be used for a number of projects and prototyping purposes, and supports animation, simple game designs and scrolling text among other things.

Digital Analog Converter (DAC)

The UNO R4 WiFi has a DAC with up to 12-bit resolution attached to the A0 analog pin. A DAC is used to convert a digital signal to an analog signal.
The DAC can be used for signal generation for e.g. audio applications, like generating and altering sawtooth wave.

I2C Connector

The I2C connector SM04B-SRSS-TB(LF)(SN) is connected to a secondary I2C bus on the board. Note that this connector is powered via 3.3 V.

This connector also shares the following pin connections:

JANALOG header

• A4
• A5

JDIGITAL header

• SDA
• SCL
  Note: as A4/A5 is connected to the main I2C bus, these should not be used as ADC inputs whenever the bus is in use. You can however connect I2C devices to each of these pins and connectors simultaneously.

Power Options

Power can either be supplied via the VIN pin, or via USB-C® connector. If power is supplied via VIN, the ISL854102FRZ buck converter steps the voltage down to 5 V.
Both VUSB and VIN pins are connected to the ISL854102FRZ buck converter, with Schottky diodes in place for reverse polarity & overvoltage protection respectively.
Power via USB supplies about ~4.7 V (due to Schottky drop) to the RA4M1 MCU.
The linear regulator (SGM2205-3.3XKC3G/TR) converts 5 V from either the buck converter or USB, and provides 3.3 V to a number of components, including the ESP32-S3 module.

Power Tree

Pin Voltage
The general operating voltage for UNO R4 WiFi is 5 V, however the ESP32-S3 module’s operating voltage is 3.3 V.

Note: It is very important that ESP32-S3’s pins (3.3 V) do not come in contact with any of the RA4M1’s pins (5 V), as this may damage the circuits.

Pin Current
The GPIOs on the R7FA4M1AB3CFM#AA0 microcontroller can safely handle up to 8 mA of current. Never connect devices that draw higher current directly to a GPIO as this may damage the circuit.

For powering e.g. servo motors, always use an external power supply.

Mechanical Information

Pinout

Analog

Digital

(TX)
9| D9| Digital| GPIO 9 (PWM~)
10| D8| Digital| GPIO 8
11| D7| Digital| GPIO 7
12| D6| Digital| GPIO 6 (PWM~)
13| D5| Digital| GPIO 5 (PWM~)
14| D4| Digital| GPIO 4
15| D3| Digital| GPIO 3 (PWM~)
16| D2| Digital| GPIO 2
17| D1/TX0| Digital| GPIO 1 / Serial 0 Transmitter (TX)
18| D0/TX0| Digital| GPIO 0 / Serial 0 Receiver (RX)

OFF

ICSP

Mounting Holes And Board Outline

Board Operation

1. Getting Started – IDE
   If you want to program your UNO R4 WiFi while offline you need to install the Arduino® Desktop IDE [1]. To connect the UNO R4 WiFi to your computer, you will need a Type-C® USB cable, which can also provide power to the board, as indicated by the LED (DL1).

2. Getting Started – Arduino Web Editor
   All Arduino boards, including this one, work out-of-the-box on the Arduino® Web Editor [2], by just installing a simple plugin.
   The Arduino Web Editor is hosted online, therefore it will always be up-to- date with the latest features and support for all boards. Follow [3] to start coding on the browser and upload your sketches onto your board.

3. Getting Started – Arduino IoT Cloud
   All Arduino IoT enabled products are supported on Arduino IoT Cloud which allows you to log, graph and analyze sensor data, trigger events, and automate your home or business.

4. Online Resources
   Now that you have gone through the basics of what you can do with the board you can explore the endless possibilities it provides by checking existing projects on Arduino Project Hub [4], the Arduino Library Reference [5], and the online store [6]; where you will be able to complement your board with sensors, actuators and more.

5. Board Recovery
   All Arduino boards have a built-in bootloader which allows flashing the board via USB. In case a sketch locks up the processor and the board is not reachable anymore via USB, it is possible to enter bootloader mode by doubletapping the reset button right after the power-up.

Certifications

15 Declaration of Conformity CE DoC (EU)
We declare under our sole responsibility that the products above are in conformity with the essential requirements of the following EU Directives and therefore qualify for free movement within markets comprising the European
Union (EU) and European Economic Area (EEA).

16 Declaration of Conformity to EU RoHS & REACH 211 01/19/2021
Arduino boards are in compliance with RoHS 2 Directive 2011/65/EU of the European Parliament and RoHS 3 Directive 2015/863/EU of the Council of 4 June 2015 on the restriction of the use of certain hazardous substances in electrical and electronic equipment.

Exemptions : No exemptions are claimed.
Arduino Boards are fully compliant with the related requirements of European Union Regulation (EC) 1907 /2006 concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). We declare none of the SVHCs (https://echa.europa.eu/web/guest/candidate-list-table), the Candidate List of Substances of Very High Concern for authorization currently released by ECHA, is present in all products (and also package) in quantities totaling in a concentration equal or above 0.1%. To the best of our knowledge, we also declare that our products do not contain any of the substances listed on the “Authorization List” (Annex XIV of the REACH regulations) and Substances of Very High Concern (SVHC) in any significant amounts as specified by the Annex XVII of Candidate list published by ECHA (European Chemical Agency) 1907 /2006/EC.

Conflict Minerals Declaration
As a global supplier of electronic and electrical components, Arduino is aware of our obligations with regards to laws and regulations regarding Conflict Minerals, specifically the Dodd-Frank Wall Street Reform and Consumer Protection Act, Section 1502. Arduino does not directly source or process conflict minerals such as Tin, Tantalum, Tungsten, or Gold. Conflict minerals are contained in our products in the form of solder, or as a component in metal alloys. As part of our reasonable due diligence Arduino has contacted component suppliers within our supply chain to verify their continued compliance with the regulations. Based on the information received thus far we declare that our products contain Conflict Minerals sourced from conflict-free areas.

FCC Caution

Any Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference
2. this device must accept any interference received, including interference that may cause undesired operation.

FCC RF Radiation Exposure Statement:

1. This Transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.
2. This equipment complies with RF radiation exposure limits set forth for an uncontrolled environment.
3. This equipment should be installed and operated with a minimum distance of 20 cm between the radiator & your body.

User manuals for licence-exempt radio apparatus shall contain the following or equivalent notice in a conspicuous location in the user manual or alternatively on the device or both. This device complies with Industry Canada licence-exempt RSS standard(s).
Operation is subject to the following two conditions:

1. this device may not cause interference
2. this device must accept any interference, including interference that may cause undesired operation of the device.

IC SAR Warning:
English This equipment should be installed and operated with a minimum distance of 20 cm between the radiator and your body.

Important: The operating temperature of the EUT can’t exceed 85 ℃ and shouldn’t be lower than -40 ℃.
Hereby, Arduino S.r.l. declares that this product is in compliance with essential requirements and other relevant provisions of Directive 2014/53/EU. This product is allowed to be used in all EU member states.

Company Information

Reference Documentation

/getting-started/getting-started-web- editor](https://docs.arduino.cc/cloud /web-editor/tutorials/getting-started/getting-started-web-editor)
Project Hub| https://create.arduino.cc/projecthub?by=part&part_id=11332&sort=trending
Library Reference| https://github.com/arduino-libraries/
Online Store| https://store.arduino.cc/

Change Log

Arduino® UNO R4 WiFi Modified: 26/06/2023

References

• Arduino Project Hub
• docs.arduino.cc/cloud/web-editor/tutorials/getting-started/getting-started-web-editor
• Arduino Libraries · GitHub
• Software | Arduino
• espressif.com/sites/default/files/documentation/esp32-s3-mini-1_mini-1u_datasheet_en.pdf#page=19
• espressif.com/sites/default/files/documentation/esp32-s3-mini-1_mini-1u_datasheet_en.pdf#page=21

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