Microchip Avr-iot WX User Manual

AVR-IoT Wx Hardware User

Guide

AVR-IoT Wx Hardware User Guide

Preface

Important:  This document is applicable for two different products; AVR-IoT WG (AC164160) and AVR-

IoT WA (EV15R70A). Both variants are referred to as AVR-IoT Wx in this document, and both products
have identical hardware. AVR-IoT WG is preconfigured to send data through Google Cloud IoT Core, and
AVR-IoT WA is preconfigured to send data through Amazon Web Services (AWS). Both products can be
reconfigured to send data to different cloud providers.

Introduction

The AVR-IoT Wx Development Board is a small and easily expandable demonstration and development platform for
IoT solutions, based on the AVR® microcontroller architecture using Wi-Fi® technology. It is designed to demonstrate
that the design of a typical IoT application can be simplified by partitioning the problem into three blocks:

• Smart - represented by the ATmega4808 microcontroller

• Secure - represented by the ATECC608A secure element

• Connected - represented by the ATWINC1510 Wi-Fi controller module

The AVR-IoT Wx Development Board features the following elements:

• The on-board debugger (PKOB nano) supplies full programming and debugging support through Atmel Studio/
MPLAB X IDE. It also provides access to a serial port interface (serial to USB bridge) and two logic analyzer
channels (debug GPIO).

• The on-board debugger enumerates on the PC as a mass storage interface device for easy ‘drag and drop’
programming, Wi-Fi configuration, and full access to the microcontroller application Command Line Interface
(CLI)

• A mikroBUS™ socket allows for the ability to expand the board capabilities with the selection from 450+ sensors
and actuators options offered by MikroElektronika (www.mikroe.com) via a growing portfolio of Click boards

• A light sensor used to demonstrate published data

• Microchip MCP9808 high-accuracy temperature sensor used to demonstrate published data

• Microchip MCP73871 Li-Ion/LiPo battery charger with power path management

™

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AVR-IoT Wx Hardware User Guide

• MPLAB® X IDE and Atmel Studio - Software to discover, configure, develop, program, and debug Microchip
microcontrollers.

• Application Code on GitHub - Get started with application code.

• AVR-IoT WG website - Find schematics, design files, and purchase the board. Set up for Google Cloud IoT
Core.

• AVR-IoT WA website - Find schematics, design files, and purchase the board. Set up for Amazon Web
Services.

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AVR-IoT Wx Hardware User Guide

Table of Contents

Preface........................................................................................................................................................... 1

1. Introduction............................................................................................................................................. 5

1.1. Features....................................................................................................................................... 5

1.2. Board Overview............................................................................................................................5

2. Getting Started........................................................................................................................................ 7

2.1. Quick Start....................................................................................................................................7

2.2. Design Documentation and Relevant Links................................................................................. 7

3. Application User Guide........................................................................................................................... 8

4. Hardware User Guide............................................................................................................................. 9

4.1. On-Board Debugger Overview..................................................................................................... 9

4.2. On-Board Debugger Connections.............................................................................................. 14

4.3. Power......................................................................................................................................... 15

4.4. Peripherals................................................................................................................................. 16

5. Regulatory Approval..............................................................................................................................20

5.1. United States..............................................................................................................................20

5.2. Canada.......................................................................................................................................20

5.3. Taiwan........................................................................................................................................ 21

5.4. List of Antenna Types.................................................................................................................21

6. Hardware Revision History and Known Issues..................................................................................... 22

6.1. Identifying Product ID and Revision........................................................................................... 22

6.2. AVR-IoT WG...............................................................................................................................22

6.3. AVR-IoT WA............................................................................................................................... 23

7. Document Revision History...................................................................................................................24

8. Appendix............................................................................................................................................... 25

8.1. Schematic...................................................................................................................................25

8.2. Assembly Drawing......................................................................................................................27

8.3. Mechanical Drawings................................................................................................................. 27

8.4. Getting Started with IAR.............................................................................................................28

The Microchip Website.................................................................................................................................31

Product Change Notification Service............................................................................................................31

Customer Support........................................................................................................................................ 31

Microchip Devices Code Protection Feature................................................................................................ 31

Legal Notice................................................................................................................................................. 31

Trademarks.................................................................................................................................................. 32

Quality Management System....................................................................................................................... 32

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Worldwide Sales and Service.......................................................................................................................33

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1. Introduction

1.1 Features

• ATmega4808 AVR Microcontroller

• ATWINC1510 Wi-Fi Module

• ATECC608A CryptoAuthentication™ Device

• Preconfigured for Microchip Accounts with Different Cloud Providers

– Google Cloud IoT Core
– Amazon Web Services (AWS)

• Four User LEDs

• Two Mechanical Buttons

• TEMT6000 Light Sensor

• MCP9808 Temperature Sensor

• mikroBUS Socket

• On-board Debugger

– Board identification in Atmel Studio and Microchip MPLAB X
– One green board power and status LED
– Virtual serial port (USB CDC)
– Two logic analyzer channels (debug GPIO)

• USB and Battery Powered

• MCP73871 Li-Ion/LiPo Battery Charger

• Fixed 3.3V

AVR-IoT Wx Hardware User Guide

Introduction

1.2 Board Overview

The AVR-IoT Wx development board is a hardware platform to evaluate and develop IoT solutions with the Microchip
ATmega4808 AVR microcontroller, ATECC608A secure element, and WINC1510 Wi-Fi controller module.

The preprogrammed demo application publishes data from the on-board light and temperature sensor read by the
ATmega4808 every second to the cloud. Any data received from the cloud over the subscribed topic is sent to the
virtual serial port and can be displayed in a serial terminal application. The WINC1510 needs a connection to a Wi-Fi
network with an internet connection. The ATECC608A is used to authenticate the hardware with the cloud to uniquely
identify every board. The demo application source code can be modified to publish data to a personal cloud account
to get started with a custom cloud application.

The figure below shows the main features and pinout of the board.

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Time r/PWM

UART RX

PD7

PA0

PC3

PA6

PA5

PA4

3.3V

GND

SP I S CK

SP I MIS O

SP I MOSI

PD4

PD6

PC1

PC0

PA3

PA2

5.0V

GND

UART TX

I2C SCL

I

2

C SDA

Wi-Fi Status LED

PD3

Conn ec tion S tatus LED

PD2

Data Trans fer LED

PD1

Error Status LED

PD0

PF5

USER SWITCH 1

PF6

USER SWITCH 0

ATWINC1 510 Wi-Fi®Mo dule

Mic ro US B Conne cto r

Po wer/S tatus LED

Pro gram me r/Debu gg er

ADC AIN7

ATMEGA4808 Mic ro controlle r

Charg e Status LEDs

LiPo Con ne cto r

MCP7 387 1 LiPo Charger

ATECC608A Sec ure Ele men t

Light Se ns or

MCP9 808 Tempe rature Se ns or

MIC3305 0 Voltag e Re gu lato r

SP I CS

Res et

Interrupt

AVR-Io T WG Develo pme nt Board Pino ut

AVR-IoT Wx Hardware User Guide

Figure 1-1. AVR-IoT Wx Development Board Overview

Introduction

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AVR-IoT Wx Hardware User Guide

2. Getting Started

2.1 Quick Start

Steps to start exploring the board:

1. Connect the board to your computer.

2. Open the “CLICK-ME.HTM” file on the “CURIOSITY” mass storage disk and follow the instructions.

2.1. Download the latest application .hex firmware.

2.2. Download the Wi-Fi configuration file "WIFI.cfg".

3. Drag and drop the application .hex file on the "CURIOSITY" drive.

4. Drag and drop the “WIFI.cfg” configuration file on the “CURIOSITY” drive.

The board will now connect to your Wi-Fi network and send data to the website opened in step 2 through a cloud
provider.

2.2 Design Documentation and Relevant Links

The following list contains links to the most relevant documents and software for the AVR-IoT Wx.

Getting Started

• AVR-IoT WG website - Find schematics, design files, and purchase the board. Set up for Google Cloud IoT
Core.

• AVR-IoT WG on microchipDIRECT - Purchase this board on Microchip Direct.

• AVR-IoT WA website - Find schematics, design files, and purchase the board. Set up for Amazon Web
Services.

• AVR-IoT WA on microchipDIRECT - Purchase this board on Microchip Direct.

• MPLAB Data Visualizer - MPLAB Data Visualizer is a program used for processing and visualizing data. The
Data Visualizer can receive data from various sources such as serial ports and on-board debugger’s Data
Gateway Interface, as found on Curiosity Nano and Xplained Pro boards.

• Atmel Studio - Free IDE for the development of C/C++ and assembler code for microcontrollers.

• MPLAB® X IDE - MPLAB X IDE is a software program that runs on a PC (Windows®, Mac OS®, Linux®) to
develop applications for Microchip microcontrollers and digital signal controllers. It is called an Integrated
Development Environment (IDE) because it provides a single integrated “environment” to develop code for
embedded microcontrollers.

• IAR Embedded Workbench® for AVR® - This is a commercial C/C++ compiler that is available for AVR
microcontrollers. There is a 30-day evaluation version as well as a 4 KB code-size-limited kick-start version
available from their website.

• Atmel START - Atmel START is an online tool that helps the user to select and configure software components
and tailor your embedded application in a usable and optimized manner.

• Microchip Sample Store - Microchip sample store where you can order samples of devices.

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3. Application User Guide

The ATmega4808 mounted on AVR-IoT Wx is preprogrammed with an application ready to publish data to a
Microchip account with a cloud provider, and subscribe to data sent from https://avr-iot.com through the cloud
provider. AVR-IoT WA is preconfigured for Amazon Web Services (AWS), and AVR-IoT WG is preconfigured for
Google Cloud IoT Core. The data is read from the cloud and presented to the user on https://avr-iot.com.

AVR-IoT WA

The application publishes data through Amazon Web Services, and the firmware is available on GitHub: https://

github.com/microchip-pic-avr-solutions/avr-iot-aws-sensor-node-mplab.

AVR-IoT WG

The application publishes data through Google Cloud IoT Core, and the firmware is available on GitHub: https://

github.com/microchip-pic-avr-solutions/avr-iot-google-sensor-node-mplab.

For in-depth information about the preprogrammed demo application and how to develop your application, see the full
AVR-IoT WG Application User Guide: https://www.microchip.com/mymicrochip/filehandler.aspx?

ddocname=en607553.

Setup for Different Cloud Accounts

Any AVR-IoT Wx kit can be reprovisioned to publish data to either Microchips sandbox account at Amazon Web
Services, Microchips sandbox account at Google Cloud IoT Core, or to a personal account.

Download the IoT Provisioning Tool package, compatible with Windows, Mac and Linux to get started: https://

www.microchip.com/mymicrochip/filehandler.aspx?ddocname=en1001525.

AVR-IoT Wx Hardware User Guide

Application User Guide

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4. Hardware User Guide

4.1 On-Board Debugger Overview

AVR-IoT Wx contains an on-board debugger for programming and debugging. The on-board debugger is a composite
USB device consisting of several interfaces:

• A debugger that can program and debug the ATmega4808 in Atmel Studio/MPLAB X IDE

• A mass storage device that allows drag-and-drop programming of the ATmega4808

• A virtual serial port (CDC) that is connected to a Universal Asynchronous Receiver/Transmitter (UART) on the
ATmega4808, and provides an easy way to communicate with the target application through terminal software

• A Data Gateway Interface (DGI) for code instrumentation with logic analyzer channels (debug GPIO) to visualize
program flow

The on-board debugger controls a Power and Status LED (marked PS) on the AVR-IoT Wx Board. The table below
shows how the LED is controlled in different operation modes.

Table 4-1. On-Board Debugger LED Control

Operation Mode Power and Status LED

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Boot Loader mode The LED blinks slowly during power-up

Power-up The LED is ON

Normal operation The LED is ON

Programming Activity indicator: The LED blinks slowly during programming/debugging

Drag-and-drop
programming

Fault The LED blinks rapidly if a power Fault is detected

Sleep/Off The LED is OFF. The on-board debugger is either in a sleep mode or powered down.

4.1.1 Debugger

The on-board debugger on the AVR-IoT Wx Board appears as a Human Interface Device (HID) on the host
computer’s USB subsystem. The debugger supports full-featured programming and debugging of the ATmega4808
using Atmel Studio/MPLAB X IDE, as well as some third-party IDEs.

Success: The LED blinks slowly for 2 sec.

Failure: The LED blinks rapidly for 2 sec.

This can occur if the board is externally powered.

Info:  Slow blinking is approximately 1 Hz, and rapid blinking is approximately 5 Hz.

Remember:  Keep the debugger’s firmware up-to-date. Firmware upgrades are done automatically when

using Atmel Studio/MPLAB X IDE.

4.1.2 Virtual Serial Port (CDC)

The virtual serial port (CDC) is a general purpose serial bridge between a host PC and a target device.

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4.1.2.1 Overview

Target MCU

UART TX

UART RX

Debugger

USB

CDC RX

CDC TX

PC

Terminal

Software

Target

Receive

Target

Send

Terminal
Receive

Terminal

Send

The on-board debugger implements a composite USB device that includes a standard Communications Device Class
(CDC) interface, which appears on the host as a virtual serial port. The CDC can be used to stream arbitrary data in
both directions between the host computer and the target: All characters sent through the virtual serial port on the
host computer will be transmitted as UART on the debugger’s CDC TX pin, and UART characters captured on the
debugger’s CDC RX pin will be returned to the host computer through the virtual serial port.

Figure 4-1. CDC Connection

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Info:  As shown in Figure 4-1, the debugger’s CDC TX pin is connected to a UART RX pin on the target

for receiving characters from the host computer. Similarly, the debugger’s CDC RX pin is connected to a
UART TX pin on the target for transmitting characters to the host computer.

4.1.2.2 Operating System Support

On Windows machines, the CDC will enumerate as Curiosity Virtual COM Port and appear in the Ports section of the
Windows Device Manager. The COM port number can also be found there.

Info:  On older Windows systems, a USB driver is required for CDC. This driver is included in installations
of Atmel Studio/MPLAB X IDE.

On Linux machines, the CDC will enumerate and appear as /dev/ttyACM#.

Info:  tty* devices belong to the “dialout” group in Linux, so it may be necessary to become a member of
that group to have permissions to access the CDC.

On MAC machines, the CDC will enumerate and appear as /dev/tty.usbmodem#. Depending on which terminal
program is used, it will appear in the available list of modems as usbmodem#.

Info:  For all operating systems: Be sure to use a terminal emulator that supports DTR signaling. See
Section 3.1.2.4 “Signaling”.

4.1.2.3 Limitations

Not all UART features are implemented in the on-board debugger CDC. The constraints are outlined here:

• Baud rate: Must be in the range of 1200 bps to 500 kbps. Any baud rate outside this range will be set to the
closest limit, without warning. Baud rate can be changed on-the-fly.

• Character format: Only 8-bit characters are supported.

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• Parity: Can be odd, even, or none.

• Hardware flow control: Not supported.

• Stop bits: One or two bits are supported.

4.1.2.4 Signaling

During USB enumeration, the host OS will start both communication and data pipes of the CDC interface. At this
point, it is possible to set and read back the baud rate and other UART parameters of the CDC, but data sending and
receiving will not be enabled.

When a terminal connects on the host, it must assert the DTR signal. As this is a virtual control signal implemented
on the USB interface, it is not physically present on the board. Asserting the DTR signal from the host will indicate to
the on-board debugger that a CDC session is active. The debugger will then enable its level shifters (if available), and
start the CDC data send and receive mechanisms.

Deasserting the DTR signal will not disable the level shifters but will disable the receiver so no further data will be
streamed to the host. Data packets that are already queued up for sending to the target will continue to be sent out,
but no further data will be accepted.

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Remember:  Set up the terminal emulator to assert the DTR signal. Without the signal, the on-board

debugger will not send or receive any data through its UART.

Tip:  The on-board debugger’s CDC TX pin will not be driven until the CDC interface is enabled by the
host computer. Also, there are no external pull-up resistors on the CDC lines connecting the debugger and
the target, which means that during power-up, these lines are floating. To avoid any glitches resulting in
unpredictable behavior like framing errors, the target device should enable the internal pull-up resistor on
the pin connected to the debugger’s CDC TX pin.

4.1.2.5 Advanced Use

CDC Override Mode

In normal operation, the on-board debugger is a true UART bridge between the host and the device. However, in
certain use cases, the on-board debugger can override the basic operating mode and use the CDC TX and RX pins
for other purposes.

Dropping a text file into the on-board debugger’s mass storage drive can be used to send characters out of the
debugger’s CDC TX pin. The filename and extension are trivial, but the text file must start with the characters:

CMD:SEND_UART=

The maximum message length is 50 characters – all remaining data in the frame are ignored.

The default baud rate used in this mode is 9600 bps, but if the CDC is already active or has been configured, the
previously used baud rate still applies.

USB-Level Framing Considerations

Sending data from the host to the CDC can be done byte-wise or in blocks, which will be chunked into 64-byte USB
frames. Each such frame will be queued up for sending to the debugger’s CDC TX pin. Transferring a small amount
of data per frame can be inefficient, particularly at low baud rates, because the on-board debugger buffers frames
and not bytes. A maximum of four 64-byte frames can be active at any time. The on-board debugger will throttle the
incoming frames accordingly. Sending full 64-byte frames containing data is the most efficient method.

When receiving data on the debugger’s CDC RX pin, the on-board debugger will queue up the incoming bytes into
64-byte frames, which are sent to the USB queue for transmission to the host when they are full. Incomplete frames
are also pushed to the USB queue at approximately 100 ms intervals, triggered by USB start-of-frame tokens. Up to
eight 64-byte frames can be active at any time.

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If the host (or the software running on it) fails to receive data fast enough, an overrun will occur. When this happens,
the last-filled buffer frame will be recycled instead of being sent to the USB queue, and a full frame of data will be
lost. To prevent this occurrence, the user must ensure that the CDC data pipe is being read continuously, or the
incoming data rate must be reduced.

4.1.3 Mass Storage Device

The on-board debugger includes a simple Mass Storage Device implementation, which is accessible for read/write
operations via the host operating system to which it is connected.

It provides:

• Read access to basic text and HTML files for detailed kit information and support

• Write access for programming Intel® HEX formatted files into the target device’s memory

• Write access for simple text files for utility purposes

4.1.3.1 Mass Storage Device Implementation

The on-board debugger implements a highly optimized variant of the FAT12 file system that has several limitations,
partly due to the nature of FAT12 itself and optimizations made to fulfill its purpose for its embedded application.

The Curiosity Nano USB Device is USB Chapter 9-compliant as a mass storage device but does not, in any way,
fulfill the expectations of a general purpose mass storage device. This behavior is intentional.

When using the Windows operating system, the on-board debugger enumerates as a Curiosity Nano USB Device
that can be found in the disk drives section of the device manager. The CURIOSITY drive appears in the file manager
and claims the next available drive letter in the system.

The CURIOSITY drive contains approximately one MB of free space. This does not reflect the size of the target
device’s Flash in any way. When programming an Intel® HEX file, the binary data are encoded in ASCII with
metadata providing a large overhead, so one MB is a trivially chosen value for disk size.

It is not possible to format the CURIOSITY drive. When programming a file to the target, the filename may appear in
the disk directory listing. This is merely the operating system’s view of the directory, which, in reality, has not been
updated. It is not possible to read out the file contents. Removing and replugging the board will return the file system
to its original state, but the target will still contain the application that has been previously programmed.

To erase the target device, copy a text file starting with “CMD:ERASE” onto the disk.

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By default, the CURIOSITY drive contains several read-only files for generating icons as well as reporting status and
linking to further information:

• AUTORUN.ICO – icon file for the Microchip logo

• AUTORUN.INF – system file required for Windows Explorer to show the icon file

• CLICK-ME.HTM – redirect to the AVR-IoT Wx web demo application

• KIT-INFO.HTM – redirect to the development board website

• KIT-INFO.TXT – a text file containing details about the board’s debugger firmware version, board name, USB
serial number, device, and drag-and-drop support

• PUBKEY.TXT – a text file containing the public key for data encryption

• STATUS.TXT – a text file containing the programming status of the board

4.1.3.2 Fuse Bytes

Fuse Bytes (AVR® MCU Targets)

When doing drag-and-drop programming, the debugger masks out fuse bits that attempt to disable Unified Program
and Debug Interface (UPDI). This means that the UPDI pin cannot be used in its reset or GPIO modes; selecting one

Info:  STATUS.TXT is dynamically updated by the on-board debugger. The contents may be cached by
the OS and, therefore, do not reflect the correct status.

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of the alternative functions on the UPDI pin would render the device inaccessible without using an external debugger
capable of high-voltage UPDI activation.

4.1.3.3 Limitations of drag-and-drop programming

Lock bits

Lock bits included in the hex file will be ignored when using drag-and-drop programming. To program lock bits, use
Atmel Studio/MPLAB X IDE.

Enabling CRC check in fuses

It is not advisable to enable the CRC check in the target device’s fuses when using drag-and-drop programming. This
because a subsequent chip-erase (which does not affect fuse bits) will effect a CRC mismatch, and the application
will fail to boot. To recover a target from this state, a chip-erase must be done using Atmel Studio/MPLAB X IDE,
which will automatically clear the CRC fuses after erasing.

4.1.3.4 Special Commands

Several utility commands are supported by copying text files to the mass storage disk. The filename or extension is
irrelevant – the command handler reacts to content only.

Table 4-2. Special File Commands

Command Content Description

CMD:ERASE

CMD:SEND_UART=

CMD:RESET

Executes a chip erase of the target

Sends a string of characters to the CDC UART. See “CDC Override Mode”.

Resets the target device by entering Programming mode and then exiting
Programming mode immediately thereafter. Exact timing can vary according to
the programming interface of the target device. (Debugger firmware v1.16 or
newer.)

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Info:  The commands listed here are triggered by the content being sent to the mass storage emulated

disk, and no feedback is provided in the case of either success or failure.

4.1.4 Data Gateway Interface (DGI)

Data Gateway Interface (DGI) is a USB interface for transporting raw and time-stamped data between on-board
debuggers and host computer-based visualization tools. MPLAB Data Visualizer is used on the host computer to
display debug GPIO data. It is available as a plug-in for MPLAB® X IDE or a stand-alone application that can be used
in parallel with Atmel Studio/MPLAB X IDE.

Although DGI encompasses several physical data interfaces, the AVR-IoT Wx implementation includes logic analyzer
channels:

• Two debug GPIO channels (also known as DGI GPIO)

4.1.4.1 Debug GPIO

Debug GPIO channels are timestamped digital signal lines connecting the target application to a host computer
visualization application. They are typically used to plot the occurrence of low-frequency events on a time-axis – for
example, when certain application state transitions occur.

The figure below shows the monitoring of the digital state of a mechanical switch connected to a debug GPIO in
MPLAB Data Visualizer.

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Figure 4-2. Monitoring Debug GPIO with MPLAB Data Visualizer

Debug GPIO channels are timestamped, so the resolution of DGI GPIO events is determined by the resolution of the
DGI timestamp module.

Important:  Although bursts of higher-frequency signals can be captured, the useful frequency range of
signals for which debug GPIO can be used is up to about 2 kHz. Attempting to capture signals above this
frequency will result in data saturation and overflow, which may cause the DGI session to be aborted.

4.1.4.2 Timestamping

DGI sources are timestamped as they are captured by the debugger. The timestamp counter implemented in the
Curiosity Nano debugger increments at 2 MHz frequency, providing a timestamp resolution of a half microsecond.

4.2 On-Board Debugger Connections

The table below shows the connections between the target and the debugger section. All connections between the
target and the debugger are tri-stated as long as the debugger is not actively using the interface. Hence, since there
are little contaminations of the signals, the pins can be configured to anything the user wants.

For further information on how to use the capabilities of the on-board debugger, see 4.1 On-Board Debugger

Overview.

Table 4-3. On-Board Debugger Connections

ATmega4808 Pin Debugger Pin Function Shared Functionality

PF1 CDC TX UART2 RX (ATmega4808 RX line) —

PF0 CDC RX UART2 TX (ATmega4808 TX line) —

UPDI DBG0 UPDI —

PF6 DBG1 DGI GPIO0 SW0

PF5 DBG2 DGI GPIO1 SW1

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4.3 Power

USB

nEDBG

Power Source

Cut Strap

Power Consumer

Power Converter

VUSB

MIC33050

(buck)

MCP73871

Li-Ion / Li-Po

Battery

Charger

Battery Charger

Battery

Connector

(JST)

VCC_P3V3

V

BAT

VMUX

cut-strap

Peripherals

mBUS

WINC1510

ATmega4808

cut-strap

WARNING

4.3.1 Power Source

The board can be powered through the USB port or by a Li-Ion/LiPo battery. The board contains one buck converter
for generating 3.3V for the debugger, target, and peripherals.

The maximum available current from the USB is limited to 500 mA. The current will be shared between charging the
battery (if connected) and the target application section.

Figure 4-3. Power Supply Block Diagram

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4.3.2 Battery Charger

AVR-IoT Wx features an MCP73871 Li-Ion/LiPo charger and JST battery connector on board. The charger is
configured to limit the charge current to 100 mA to prevent the overcharging of small capacity batteries. Minimum
recommended battery capacity is 400 mAh.

Table 4-4. Charger Status LEDs

LEDs Function

Red (charging) The battery is being charged by the USB

Red (discharging) The battery voltage is low. Triggers if the voltage is under 3.1V.

Green Charge complete

Red and Green Timer Fault. The six-hour charge cycle has timed out before the complete

4.3.3 Hardware Modifications

On the bottom side of the AVR-IoT Wx board there are two cut-straps, as shown in the figure below. These are
intended for current measurement purposes. Do not leave these unconnected as the microcontrollers might get
powered through the I/O’s.

© 2020 Microchip Technology Inc.

The MCP73871 has a battery charge voltage of 4.2V. Make sure your battery has the same charge
voltage.

charge.

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AVR-IoT Wx Hardware User Guide

Hardware User Guide

Figure 4-4. V

The 5V supply to the mikroBUS socket is connected by default. To remove 5V to the socket, desolder the 0-ohm
resistor (0402) below the 5V text, as shown in the figure below.

Figure 4-5. mikroBUS™ 5V Footprint

Cut-Straps

CC

4.4 Peripherals

4.4.1 ATmega4808

Microchip ATmega4808 is a microcontroller featuring the AVR® processor with hardware multiplier - running at up to
20 MHz and with up to 48 KB Flash, 6 KB SRAM and 256 bytes of EEPROM in 28- and 32-pin packages. The series
uses the latest Core Independent Peripherals (CIPs) with low-power features, including event system, intelligent
analog and advanced peripherals.

4.4.2 mikroBUS™ Socket

AVR-IoT Wx features a mikroBUS socket for expanding the functionality of the development board using
MikroElektronika Click Boards and other mikroBUS add-on boards. The socket is populated with two 1x8 2.54 mm
pitch female headers and is ready to mount add-on boards.

Table 4-5. mikroBUS™ Socket Pinout

mikroBUS™ Socket Pin ATmega4808 Pin Function Shared Functionality

AN PD7 ADC AIN7 —

RST PA0 GPIO —

CS PC3 GPIO —

SCK PA6 SPI0 SCK WINC1510 SPI

MISO PA5 SPI0 MISO WINC1510 SPI

MOSI PA4 SPI0 MOSI WINC1510 SPI

+3.3V V

GND GND Ground —

PWM PD4 TCA0 WO4 —

© 2020 Microchip Technology Inc.

DD

VCC_TARGET, 3.3V
supply

User Guide

—

DS50002805B-page 16

AVR-IoT Wx Hardware User Guide

Hardware User Guide

...........continued

mikroBUS™ Socket Pin ATmega4808 Pin Function Shared Functionality

INT PD6 GPIO —

RX PC1 UART1 RX —

TX PC0 UART1 TX —

SCL PA3 TWI0 SCL MCP9808 and

ATECC608A

SDA PA2 TWI0 SDA MCP9808 and

ATECC608A

+5V — VCC_MUX1, MCP73871

GND GND Ground —

Info: 

1) A 0-ohm resistor has been soldered to connect the VCC_MUX pin to the mikroBUS socket. If an add-on
module cannot handle 5V on this pin, the 0-ohm resistor has to be removed. For more information, see

4.3.3 Hardware Modifications.

4.4.3 WINC1510 Wi-Fi® Module

Microchip's WINC1510 is a low-power consumption 802.11 b/g/n IoT module, specifically optimized for low-power IoT
applications. The module integrates Power Amplifier (PA), Low-Noise Amplifier (LNA), switch, power management,
and a printed antenna or a micro co-ax (U.FL) connector for an external antenna resulting in a small form factor
(21.7x14.7x2.1 mm) design. It is interoperable with various vendors’ 802.11 b/g/n access points. This module
provides SPI ports to interface with a host controller.

WINC1510 provides internal Flash memory as well as multiple peripheral interfaces, including UART and SPI. The
only external clock source needed for WINC1510 is the built-in, high-speed crystal or oscillator (26 MHz). WINC1510
is available in a QFN package or as a certified module.

The communication interface between the ATmega4808 and the WINC1510 Wi-Fi module is SPI, together with some
enable signals and interrupt. The rest of the connections are left unconnected.

Table 4-6. WINC1510 Connections

—

output

WIN1510 Pin ATmega4808 Pin Function Shared Functionality

4 RESET_N PA1 GPIO —

9 GND GND Ground —

10 SPI_CFG VCC_TARGET — —

11 WAKE PF4 GPIO —

12 GND GND Ground —

13 IRQN PF2 ASYNC EXT INT —

15 SPI_MOSI PA4 SPI0 MOSI mikroBUS

16 SPI_SSN PA7 SPI0 SS —

17 SPI_MISO PA5 SPI0 MISO mikroBUS

18 SPI_SCK PA6 SPI0 SCK mikroBUS

20 VBAT VCC_TARGET 3.3V supply —

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 17

...........continued

WIN1510 Pin ATmega4808 Pin Function Shared Functionality

22 CHIP_EN PF3 GPIO —

23 VDDIO VCC_TARGET 3.3V supply —

28 GND GND Ground —

29 PADDLE GND — —

4.4.4 ATECC608A

ATECC608A is a secure element from the Microchip CryptoAuthentication portfolio with advanced Elliptic Curve
Cryptography (ECC) capabilities. With ECDH and ECDSA being built right in, this device is ideal for the rapidly
growing Internet of Things (IoT) market by easily supplying the full range of security, such as confidentiality, data
integrity, and authentication to systems with MCU or MPUs running encryption/decryption algorithms. Similar to all
Microchip CryptoAuthentication products, the new ATECC608A employs ultra-secure, hardware-based cryptographic
key storage and cryptographic countermeasures that eliminate any potential backdoors linked to software
weaknesses.

The ATECC608A CryptoAuthentication device on the AVR-IoT Wx board is used to authenticate the hardware with
cloud providers to uniquely identify every board.

Note:  7-bit I2C address: 0x58.

Table 4-7. ATECC608A Connections

AVR-IoT Wx Hardware User Guide

Hardware User Guide

ATECC608A Pin ATmega4808 Pin Function Shared Functionality

SDA PA2 TWI0 SDA MCP9808 and mikroBUS

SCL PA3 TWI0 SCL MCP9808 and mikroBUS

4.4.5 Temperature Sensor

The MCP9808 digital temperature sensor converts temperatures between -20°C and +100°C to a digital word with
±0.25°C/±0.5°C (typical/maximum) accuracy.

Additional features:

• Accuracy:

– ±0.25°C (typical) from -40°C to +125°C
– ±0.5°C (maximum) from -20°C to +100°C

• User Selectable Measurement Resolution:

– 0.5°C, 0.25°C, 0.125°C, 0.0625°C

• User Programmable Temperature Limits:

– Temperature Window Limit
– Critical Temperature Limit

• User Programmable Temperature Alert Output

• Operating Voltage Range:

– 2.7V to 5.5V

• Operating Current:

– 200 μA (typical)

• Shutdown Current:

– 0.1 μA (typical)

The MCP9808 temperature sensor is connected to the ATmega4808 through I2C and a GPIO for the user­configurable alert output.

Note:  7-bit I2C address: 0x18.

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 18

Table 4-8. MCP9808

MCP9808 Pin ATmega4808 Pin Function Shared Functionality

SDA PA2 TWI0 SDA ATECC608A and mikroBUS

SCL PA3 TWI0 SCL ATECC608A and mikroBUS

Alert PC2 ASYNC External Interrupt —

4.4.6 Light Sensor

A TEMT6000X01 light sensor is mounted on the AVR-IoT Wx board for measuring the light intensity. The sensor is a
current source that will induce a voltage across the series resistor, which in turn can be measured by the
ATmega4808 ADC. The current is exponentially relative to illuminance, from about 10 µA@20lx to 50 µA@100lx. The
series resistor has a value of 10 kΩ.

Table 4-9. Light Sensor Connection

ATmega4808 Pin Function Shared Functionality

PD5 ADC AIN5 —

4.4.7 LED

There are four LEDs available on the AVR-IoT Wx board that can be controlled with PWM or GPIO. The LEDs can be
activated by driving the connected I/O line to GND.

Table 4-10. LED Connections

AVR-IoT Wx Hardware User Guide

Hardware User Guide

ATmega4808 Pin Function Description

PD0 TCA0 WO0 Red LED

PD1 TCA0 WO1 Yellow LED

PD2 TCA0 WO2 Green LED

PD3 TCA0 WO3 Blue LED

4.4.8 Mechanical Buttons

AVR-IoT Wx contains two mechanical buttons. These are generic user-configurable buttons. When a button is
pressed, it will drive the connected I/O line to ground (GND).

Info:  There are no pull-up resistors connected to the generic user buttons. Remember to enable the
internal pull-up in the ATmega4808 to use the buttons.

Table 4-11. Mechanical Button

ATmega4808 Pin Description Shared Functionality

PF6 User switch 0 (SW0) On-board debugger

PF5 User switch 1 (SW1) On-board debugger

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 19

5. Regulatory Approval

The AVR-IoT Wx development board has been testedby the following standards:

Emission:

• FCC Part 15 subpart B:2018 (Class B)

• EN55032:2015 (Class B)

Immunity:

• EN55024:2010+A1:2015

• EN61000-4-2:2009 (contact: level 2 (±4 kV), air: level3 (±8 kV))

• EN61000-4-3:2006+A2:2010 (80 - 1000 MHz, level 2 (3 V/M))

• EN61000-4-8:2010 (level 2 (3 A/m), continuous field)

The development board contains the wireless transmitter module ATWINC1510-MR210PB, which has the following
approval and/or registrations:

• United States/FCC ID: 2ADHKATWINC1510

• Canada

– IC: 20266-ATWINC1510
– HVIN: ATWINC1510-MR210PB
– PMN: ATWINC1510-MR210PB

• Europe - CE

• Japan/MIC: 005-101762

• Korea/KCC: R-CRM-mcp-WINC1510MR210P

• Taiwan/NCC: CCAN18LP0320T0

• China/SRRC: CMIIT ID: 2018DJ1310

AVR-IoT Wx Hardware User Guide

Regulatory Approval

5.1 United States

Contains Transmitter Module FCC ID: 2ADHKATWINC1510.

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of
the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and can radiate radio frequency energy, and if not installed
and used in accordance with the instructions, may cause harmful interference to radio communications. However,
there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna

• Increase the separation between the equipment and receiver

• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected

• Consult the dealer or an experienced radio/TV technician for help

5.2 Canada

Contains IC: 20266-ATWINC1510.

This device complies with Industry Canada's license-exempt RSS standard(s). Operation is subject to the following
two conditions:

(1) This device may not cause interference, and

(2) This device must accept any interference, including interference that may cause undesired operation of the
device.

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 20

Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence.
L'exploitation est autorisée aux deux conditions suivantes:

(1) l'appareil ne doit pas produire de brouillage, et

(2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible
d'en compromettre le fonctionnement.

Guidelines on Transmitter Antenna for License Exempt Radio Apparatus:

Under Industry Canada regulations, this radio transmitter may only operate using an antenna of a type and maximum
(or lesser) gain approved for the transmitter by Industry Canada. To reduce potential radio interference to other users,
the antenna type and its gain should be so chosen that the equivalent isotropically radiated power (e.i.r.p.) is not
more than that necessary for successful communication.

Conformément à la réglementation d'Industrie Canada, le présent émetteur radio peut fonctionner avec une antenne
d'un type et d'un gain maximal (ou inférieur) approuvé pour l'émetteur par Industrie Canada. Dans le but de réduire
les risques de brouillage radioélectrique à l'intention des autres utilisateurs, il faut choisir le type d'antenne et son
gain de sorte que la puissance isotrope rayonnée équivalente (p.i.r.e.) ne dépasse pas l'intensité nécessaire à
l'établisse-ment d'une communication satisfaisante.

5.3 Taiwan

Contains module: CCAN18LP0320T0.

注意 !

依據 低功率電波輻射性電機管理辦法

第十二條 經型式認證合格之低功率射頻電機，非經許 可， 公司、商號或使用者均不得擅自變更頻率、加大功率或 變
更原設計 之特性及功能。

第十四條 低功率射頻電機之使用不得影響飛航安全及 干擾合法通信； 經發現有干擾現象時，應立即停用，並改善至無
干擾時 方得繼續使用。

前項合法通信，指依電信規定作業之無線電信。

低功率射頻電機須忍受合法通信或工業、科學及醫療用 電波輻射性 電機設備之干擾。

AVR-IoT Wx Hardware User Guide

Regulatory Approval

5.4 List of Antenna Types

ATWINC1510-MR210 does not allow the use of external antennas and is tested with the PCB antenna on the
module.

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 21

AVR-IoT Wx Hardware User Guide

Hardware Revision History and Known Issues

6. Hardware Revision History and Known Issues

This user guide is written to provide information about the latest available revision of the board. The following
sections contain information about known issues, a revision history of older revisions, and how older revisions differ
from the latest revision.

6.1 Identifying Product ID and Revision

The revision and product identifier of the AVR-IoT Wx boards can be found in two ways: Either by utilizing the Atmel
Studio/MPLAB X IDE Kit Window or by looking at the sticker on the bottom side of the PCB.

By connecting an AVR-IoT Wx to a computer with Atmel Studio/MPLAB X IDE running, the Kit Window will pop up.
The first six digits of the serial number, which is listed under kit information, contain the product identifier and revision.

Tip:  The Kit Window can be opened in MPLAB® X IDE through the menu bar Window > Kit Window.

The same information can be found on the sticker on the bottom side of the PCB. Most boards will have the identifier
and revision printed in plain text as A09-nnnn\rr, where “nnnn” is the identifier, and “rr” is the revision. Boards with
limited space have a sticker with only a data matrix code, containing the product identifier, revision, and serial
number.

The serial number string has the following format:

"nnnnrrssssssssss"

n = product identifier

r = revision

s = serial number

The product identifier for AVR-IoT WG is A09-3203.

The product identifier for AVR-IoT WA is A09-3349.

6.2 AVR-IoT WG

6.2.1 Revision 9

New PCB revision 5 with minor silkscreen changes.

6.2.2 Revision 8

The Wi-Fi module WINC1510 order code used on revision 8 is ATWINC1510-MR210PB1961 (firmware 19.6.1).

J201 and J202 (mikroBUS socket), and R204 (0-ohm resistor to apply 5V to mikroBUS socket) are not populated on
this revision.

PCB revision 4.

6.2.3 Revision 7

Revision 7 is the initial revision available on microchipDIRECT.

The Wi-Fi module WINC1510 order code used on revision 7 is ATWINC1510-MR210PB1952 (firmware 19.5.2). The
firmware was upgraded to version 19.6.1 in production.

J201 and J202 (mikroBUS socket), and R204 (0-ohm resistor to apply 5V to mikroBUS socket) are not populated on
this revision.

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 22

New PCB revision 4, fixing issues with the MCP73871 Li-Ion/LiPo charger connections.

6.2.4 Revision 6

Revision 6 is the early adopter revision. It does not have the MCP73871 Li-Ion/LiPo charger or battery connector
components mounted, and can only be powered through USB.

J201 and J202 (mikroBUS socket), and R204 (0-ohm resistor to apply 5V to mikroBUS socket) are not populated on
this revision.

The Wi-Fi module WINC1510 order code used on revision 6 is ATWINC1510-MR210PB1952 (firmware 19.5.2). The
firmware was upgraded to version 19.6.1 in production.

PCB revision 3.

Related Links

4.3.2 Battery Charger

6.3 AVR-IoT WA

6.3.1 Revision 1

Revision 1 of AVR-IoT WA is the initial released revision. The hardware is identical to AVR-IoT WG revision 9.

Drag and drop configuration of Wi-Fi credentials does not work with the application firmware preprogrammed on this
revision of the kit. Follow the instructions in 2.1 Quick Start to download and upgrade the application firmware.

PCB revision 5.

AVR-IoT Wx Hardware User Guide

Hardware Revision History and Known Issues

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 23

7. Document Revision History

Doc. rev. Date Comment

B 03/2020 Updated with AVR-IoT WG revsion 9, updated with information about AVR-IoT

WA.

A 10/2018 Initial document release.

AVR-IoT Wx Hardware User Guide

Document Revision History

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 24

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Drawn By:

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Sheet Title

Target MCU

Engineer:

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A08-2937 5

Size

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100n

C204

PA5_SPI_MISO

PA6_SPI_SCK

PA7_SPI_SS

PC0_UART1_TX

PC1_UART1_RX

PC2_TEMP_INT

PD0_TCA0_WO0

PA3_I2C_SCL

PA0_MBUS_RST

UPDI

PF2_WINC_INT

PF3_WINC_EN

PF1_UART2_RX

PF0_UART2_TX

GND

VCC_TARGET

GND

100n

C200

PA2_I2C_SDA

PA1_WINC_RST

PF4_WINC_WAKE

PA4_SPI_MOSI

1k

R213

USER LE DS

VCC_TARGET

PF6_SW0_DGI

USER BUTT ONS

330R

R207

BLM18PG471SN1

L200

ATmega4808

2.2uF

C201

DBG0

CDC_UART

TX

RX

UART

DBG1

DBG2

2185-108SS0CYNP1

1234567

8

J201

2185-108SS0CYNP1

1234567

8

J202

mikr oBUS

GND GND

AN

RSTCSSCK

MISO

MOSI

+3.3V

GND

PWM

INTRXTX

SCL

SDA

+5V

GND

Head er (Fema le)

TM

ATmega4808-MFR

PA3

1

(EXTCLK)PA0

30

PA1

31

PA2

32

PA42PA53PA64PA75PC06PC17PC2

8

PC3

9

PD0

10

PD1

11

PD2

12

PD3

13

PD4

14

PD5

15

PD6

16

PD7

17

AVDD

18

GND

19

(TOSC1) PF020(TOSC2) PF1

21

PF222PF323PF4

24

PF5

25

PF6

26

UPDI

27

VDD

28

GND

29

PAD

33

U201

WINC1510

10uF

C203

10nF

C202

1 2

43

5

KMR221G

SW200

330R

R208

1 2

43

5

KMR221G

SW201

1k

R212

1k

R209

1k

R206

GND

SDA5SCL

6

GND

4

VCC8PAD

9

NC1NC2NC3NC

7

U202

GND

GND

100k

R200

PA5_SPI_MISO

PA6_SPI_SCK

PA7_SPI_SS

PA4_SPI_MOSI

VCC_TARGET

VCC_TARGET

PA3_I2C_SCL

PA2_I2C_SDA

VCC_TARGET

GND

100n

C205

PA3_I2C_SCL

PA2_I2C_SDA

PA5_SPI_MISO

PA6_SPI_SCK

PA4_SPI_MOSI

PF5_SW1_DGI

GND

Cr yptoAuth enticat ionTM Temper atu re Sensor

GND

VCC_TARGET

100k

R211

VCC_TARGET

4.7k
R202

4.7k
R203

VCC_TARGET

VCC_TARGET

TP202

TP204

TP205

TP206

TP203

2 1

GREEN LED

SML-P12MTT86R

D201

RED LED

SML-P12VTT86R

2 1

D200

PF6_SW0_DGI

PF5_SW1_DGI

I2C address: 0x18

WINC_UART_RX

WINC_UART_TX

PD1_TCA0_WO1

PD2_TCA0_WO2

PD3_TCA0_WO3

PD4_TCA0_WO4

PD0_TCA0_WO0

PD1_TCA0_WO1

PD2_TCA0_WO2

PD3_TCA0_WO3

PD4_TCA0_WO4

PA1_WINC_RST

PA0_MBUS_RST

PF1_UART2_RX

PF0_UART2_TX

PD6_MBUS_INT

PD7_MBUS_AIN7

PC3_MBUS_CS

PF4_WINC_WAKE

PF3_WINC_EN

WINC_SPI_CFG

PA3_I2C_SCL

PA2_I2C_SDA

PD7_MBUS_AIN7

PD6_MBUS_INT

PF2_WINC_INT

PC2_TEMP_INT

VCC_P1V3

2 1

YELLOW LED

SML-P12YTT86R

D203

Default I2C address: 0x58

2 1

BLUE LED

SMLP13BC8TT86

D202

VCC_TARGET

VCC_TARGET

12

TEMT6000

Q200

GND

VCC_TARGET

SDA1SCL2ALERT3GND

4

A25A16A0

7

VDD

8

EP

9

MCP9808U203

PA3_I2C_SCL

PA2_I2C_SDA

GND

PC0_UART1_TX

PC1_UART1_RXPC3_MBUS_CS

PD5_LS_AIN5

Light Sensor

PD5_LS_AIN5

TP201

TP200

10k

R210

100n

C206

SW1

SW0

100k
R201

GND

VCC_MUX0R

R204

+5V

TP207

TP208

TP209 GND

GND

UPDI

PF6_SW0_DGI

PF5_SW1_DGI

ERR

DATA

CONN

WIFI

ATECC608A

ATWINC1510-MR210PB1961

RESET_N

4

CHIP_EN

22

VDDIO

23

VBAT

20

WAKE11UART_TXD14UART_RXD

19

NC

7

1P3V_TP

24

SPI_SCK18SPI_MISO17SPI_MOSI15SPI_SSN

16

SPI_CFG

10

GPIO_6

1

GPIO_5

27

GPIO_4

26

GPIO_3

25

I2C_SCL2I2C_SDA

3

GPIO_1/RTC

21

NC5NC6NC

8

IRQN

13

GND

28

GND

12

GND

9

PADDLE

29

U200

AVR-IoT Wx Hardware User Guide

Appendix

8. Appendix

8.1 Schematic

Figure 8-1. AVR-IoT Wx Schematic

User Guide

© 2020 Microchip Technology Inc.

DS50002805B-page 25

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A08-2937 5

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DEBUGG ER USB MIC RO-B CONNE CTOR

GND

USBD_P

USBD_N

100n

C107

100n

C108

RX

TX

UART

CDC_UART

1k

R106

VCC_DEBUGGER

100n

C105

GND

SRST

STATUS_LED

SHIELD

VBUS

VCC_DEBUGGER

GND

TP100

Testpoint Array

1 2

3 4

5 6

7 8

9 10

TCK

TDO

TMS

Vsup

TDI GND

TRST

SRST

VTref

GND

J102

DBG0

21

GREEN LED

SML-P12MTT86R

D102

VBUS1D-2D+3GND5SHIELD16SHIELD27ID

4

SHIELD3

8

SHIELD4

9

MU-MB0142AB2-269

J103

PAD

33

PA001PA012PA023PA03

4

GND

10

VDDANA

9

PA045PA056PA067PA07

8

PA08

11

PA09

12

PA10

13

PA11

14

PA14

15

PA15

16

PA1617PA1718PA1819PA1920PA22

21

USB_SOF/PA23

22

USB_DM/PA2423USB_DP/PA25

24

PA27

25

RESETN

26

PA28

27

GND

28

VDDCORE

29

VDDIN

30

SWDCLK/PA30

31

SWDIO/PA31

32

SAMD21E18A-MUT

U100

USBD_P

USBD_N

GND

1u

C106

VCC_MCU_CORE

VCC_DEBUGGER

VCC_DEBUGGER

GND

GND

GND

GND

DBG2

DBG3_CTRL

S1_0_TX

S0_2_TX

DAC

VTG_ADC

RESERVED

S0_3_CLK

DBG0_CTRL

CDC_TX_CTRL

BOOT

DEBUGGE R POWE R/STATUS LED

1k

R110

DBG1

DBG1_CTRL

REG_ENABLE

100k

R107

100k

R108

SWCLK

100k

R113

GND

SRST

DEBUGGE R TEST POINT

DBG2_CTRL

CDC_RX_CTRL

100k

R111

SWCLK

DBG2_GPIO

UPDI

UPDI

GPIO

GPIO

-

Signal

DBG0

DBG1

DBG2

DBG3

Interface

CDC TX

CDC RX

UART RX

UART TX

TARGET

VBUS_ADC

VCC -

VTG_ADC

ID_SYS

VTG_EN

VBUS_ADC

SWDIO

SWDIO

GND

VOFF

VCC_DEBUGGER

330R

R112

330R

R114

330R

R109

DBG0

DBG2

S1_1_RX

S0_0_RX

VCC_P3V3

GND

GND

4.7uF

C100

GND

Li-Po/Li-Ion Battery

4.7uF

C101

GND

560p

C102

SW

4

PGND

2

VOUT

7

SNS

10

EN

9

VOUT

8

SW

5

VIN

1

AGND

12

EP

13

SW3SW

6

FB/CFF

11

MIC33050-SYHLU102

100k

R100

1k

R102

RED LED

SML-P12VTT86R

2 1

D101

J100

10k

R103

GND

10uF

C103

MCP73871

OUT

1

VPCC

2

SEL3PROG2

4

THERM

5

PG6STAT27STAT1/LBO

8TE9

IN18IN

19

CE

17

VSS

10

VSS

11

EP

21

PROG312PROG1

13

VBAT14VBAT15VBAT

16

OUT

20

U101

GND

4.7uF

C104

GND

VBUS

10k

R104

GND

GND

VBUS

100k

R105

1k

R101

VCC_BAT

POWE R SUPPLY AND BATTERY CH ARGER

2 1

GREEN LED

SML-P12MTT86R

D100

1

2

J101

VCC_MUX

VCC_MUX

J104

VCC_DEBUGGER

VCC_TARGET

DBG1

VBUS

AVR programming

connector for factory

programming of Debugger

MIC33050:

Vin: 2.5V to 5.5V

Vout: Fixed 3.3V

Imax: 600mA

AVR-IoT Wx Hardware User Guide

Appendix

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 26

8.2 Assembly Drawing

®

AN / PD7

PC0 / TX

GNDGND

LABE L

PD4 / PWM

SCK / PA6

MISO / PA5PA3 / SC L

c

PCBA

CS / P C3PC1 / RX

+3.3V+5V

RST / PA0PD6 / INT

MOSI / PA4PA2 / S DA

t

C

-IoT

E

R

100mil

1000m il

100mil

600mil

200mil

100mil

800mil

200mil

2500mil

100mil

R 1,20mm x 2

R 100mil x 4

16,46mm

R 1,60mm x 4

Figure 8-2. AVR-IoT Wx Assembly Drawing Top

Figure 8-3. AVR-IoT Wx Assembly Drawing Bottom

AVR-IoT Wx Hardware User Guide

Appendix

8.3 Mechanical Drawings

The figures below show the board’s mechanical drawing and connector placement.

Figure 8-4. Mechanical Drawing

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 27

Figure 8-5. Connector Placement

800mil

500mil

USB

900mil

8,93mm

100mil

LIPO

BATTERY

8.4 Getting Started with IAR

IAR Embedded Workbench® for AVR® is a proprietary high-efficiency compiler not based on GCC. Programming and
debugging of AVR-IoT Wx is supported in IAR™ Embedded Workbench for AVR using the Atmel-ICE interface. Some
initial settings must be set up in the project to get the programming and debugging to work.

The following steps will explain how to get your project ready for programming and debugging:

1. Make sure you have opened the project you want to configure. Open the OPTIONS dialog for the project.

2. In the category General Options, select the Target tab. Select the device for the project, or if not listed, the

core of the device, as shown in Figure 7-7.

3. In the category Debugger, select the Setup tab. Select Atmel-ICE as the driver, as shown in Figure 7-8.

4. In the category Debugger > Atmel-ICE, select the Atmel-ICE 1 tab. Select UPDI as the interface and,
optionally, select the UPDI frequency, as shown in Figure 7-9.

AVR-IoT Wx Hardware User Guide

Appendix

Info:  If the selection of Debug Port (mentioned in step 4) is grayed out, the interface is preselected, and

the user can skip this configuration step.

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 28

Figure 8-6. Select Target Device

AVR-IoT Wx Hardware User Guide

Appendix

Figure 8-7. Select Debugger

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 29

Figure 8-8. Configure Interface

AVR-IoT Wx Hardware User Guide

Appendix

© 2020 Microchip Technology Inc.

User Guide

DS50002805B-page 30

AVR-IoT Wx Hardware User Guide

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Technical support is available through the website at: http://www.microchip.com/support

Microchip Devices Code Protection Feature

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today,

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• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code

protection does not mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection
features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital
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Legal Notice

Information contained in this publication regarding device applications and the like is provided only for your
convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with

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User Guide

DS50002805B-page 31

AVR-IoT Wx Hardware User Guide

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The Microchip name and logo, the Microchip logo, Adaptec, AnyRate, AVR, AVR logo, AVR Freaks, BesTime,
BitCloud, chipKIT, chipKIT logo, CryptoMemory, CryptoRF, dsPIC, FlashFlex, flexPWR, HELDO, IGLOO, JukeBlox,
KeeLoq, Kleer, LANCheck, LinkMD, maXStylus, maXTouch, MediaLB, megaAVR, Microsemi, Microsemi logo, MOST,
MOST logo, MPLAB, OptoLyzer, PackeTime, PIC, picoPower, PICSTART, PIC32 logo, PolarFire, Prochip Designer,
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Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BlueSky, BodyCom,
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SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.

The Adaptec logo, Frequency on Demand, Silicon Storage Technology, and Symmcom are registered trademarks of
Microchip Technology Inc. in other countries.

GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip
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All other trademarks mentioned herein are property of their respective companies.

©

2020, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.

ISBN: 978-1-5224-5710-7

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For information regarding Microchip’s Quality Management Systems, please visit http://www.microchip.com/quality.

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