Pet Activity Monitor

Reference Design to Monitor Pet Activity and Sound Featuring the Renesas Synergy™ S3A3 MCU

The Renesas Pet Activity Monitor is a practical reference design created in celebration of the Year of the Dog. This device can track your dog’s barking and activity, and data can be viewed and downloaded from your PC.


The Pet Activity Monitor is a self-contained PCB board inside a plastic casing to make it easy to attach to your pet's collar or use the included collar. This activity monitor features a Renesas Synergy™ Platform S3-series MCU, and multiple Renesas power and analog components.

The device monitors activity and sound from your pet. It attaches to the pet's collar and can count steps taken by the pet throughout the day. It can also detect barking in dogs.

Pet activity data is logged into the MCU data flash memory making it easy for you to read this data from the monitor to see what times of the day that your pet is most active. The data collected can be downloaded to a PC via a USB port on the device. Collected data and settings can be viewed and managed through the Pet Monitor PC application.

The Pet Activity Monitor is delivered preloaded with a demonstration program. The demonstration program shows several features of the Pet Activity Monitor and source code is available as a programming example for developers.

While this design has been created specifically as a pet monitor, with some modifications to code and/or additional hardware using the non-populated PMOD connector, it could be used as a remote sensor/logger for a variety of applications.

Key Features

  • Accelerometer detects movement/steps
  • MEMS microphone with the ISL28133 op amp for audio detection (barking)
  • Utilizes low power consumption
  • Low continuous active current with on/off switch
  • Powered with one LIR2032 coin cell battery rechargeable by USB or +5V wall plug
  • Quickly designed utilizing Synergy SSP API
  • PC application using Microsoft Visual Studio Community Edition to create a VB.NET application to interface to the device from Microsoft Windows.
  • Expandable with the Serial PMOD port

Software and Tools

Evaluation board installation application (pet-monitor-setup.exe) includes the following items:

  • User manual for the ISL devices
  • User manual for the Synergy S3A3
  • Pre-built PC application
  • Solution Source Project PC application
  • e2 studio project files
  • Hardware design files
  • Synergy CDC drivers for Windows OS
  • User's guide for the Pet Activity Monitor hardware

To install the PC software you will require administrator rights on your PC. This is because the installation requires drivers to be installed on your PC.

Pet Activity Monitor Case

Pet Activity Monitor Case

REN-PETMONITOR2Z Reference Design Top


REN-PETMONITOR2Z Reference Design Bottom


Related Products

Synergy™ S3A3 Series MCU

Buck-Boost Regulator

Battery Charger

Operational Amplifier

pet monitor block diagram



The Synergy S3A3 is powered at 3.3V and the internal oscillator is utilized to minimize component count. This is the heart of the design as it communicates over I2C to the accelerometer and uses its 14-bit ADC for both audio detection and low battery detection. The S3A3 micro is also set as a USB device for communication using the Renesas CDC driver for Windows.

The C-code for the S3A7 was written using the e2 studio IDE with the Synergy Software Package (SSP). The SSP offers an abundance of time-saving features to make designing with the S3 Synergy platform quick and easy.

The Renesas Synergy Platform (SSP) allows the RTOS, middleware, communication stacks, user interface, and detailed MCU functions to be accessed entirely through the application programming interface (API). Developers can immediately start developing end-product application code at the API level, thus eliminating the learning curve for software and MCU operation below the API. In this design, the following hardware features were utilized using simple API calls:

  • Express Logic RTOS Kernel, included in the Synergy SSP
  • Timers - The abundance of timers in the S3A3 MCU are used for timing certain operations
  • Real-Time Clock for time keeping
  • A/D converter for Audio detection and Low Battery Detection
  • Data Flash of the S3A3 MCU for storing user parameters and logging activity
  • USB Communication Stack for interfacing to the PC
  • Use of the HOCO built-in OSC to clock the device as well as clock the USB high-speed interface without the use of an external crystal

Debugging from within estudio is simple and intuitive. With the addition of the low-cost Synergy J-LINK Lite hardware debugger, the code in the Pet Activity Monitor can be modified or additional functionality added.

Synergy S3A3 MCU



DC/DC Switching Regulators

The ISL9120 buck-boost switcher produces the 3.3V rail that is used by the rest of the active components on the board, with a better than 90% efficiency. Even though the ISL9120 can deliver up to 800mA of power the actual power requirement for this design will draw an average of 3.4mA as it switches to different power level run modes to help keep down the power requirements. The forced bypass power saving mode can be chosen if voltage regulation is not required. The device consumes less than 3.5μA of current over the operating temperature range in forced bypass mode.

ISL9120 Buck-Boost Regulator


Charging / Battery Management

ISL9230 is a fully integrated high input voltage single-cell Li-ion battery charger with power path management function. This charger performs the CC/CV charge function required by Li-ion batteries. The charger can withstand an input voltage up to 26V but is disabled when the input voltage exceeds 6.6V OVP threshold. The input current limit and charge current are programmable with external resistors.

ISL9230 Battery Charger


User Guides

TitleTypeLast Updated DateSize
Renesas Synergy™ Platform
Renesas Pet Monitor
PDF 17 Apr 2019 1.83 MB


TitleTypeLast Updated DateSize
ISL28133 Datasheet
Single Micropower, Chopper Stabilized, RRIO Operational Amplifier
PDF 19 Jul 2018 2.29 MB
ISL9120 Datasheet
Compact High Efficiency Low Power Buck-Boost Regulator
PDF 30 Nov 2018 731 KB
ISL9230 Datasheet
High Power Li-Ion Charger W/I-Path Management
PDF 02 May 2019 1.19 MB

TitleTypeLast Updated DateSize
Pet Activity Monitor Setup v2.02
This executable contains the Pet Monitor installer, drivers, design files, project files, and documentation
EXE 01 Oct 2018 30.18 MB

Related Videos

Keeping Fit with the Pet Activity Monitor

The Pet Activity Monitor reference design monitors activity and sound from your pet!

Pet Activity Monitor Overview

The Pet Activity Monitor reference design features a Renesas Synergy™ Platform S3-series MCU, and multiple Renesas power and analog components.

WEEE Questionnaire: The WEEE Return Questionnaire is intended for the return of EEEs supplied by Renesas Electronics Europe to its customers in the European Union only.

Disclaimer: THIS MATERIAL IS PROVIDED “AS-IS” FOR EVALUATION PURPOSES ONLY. RENESAS ELECTRONICS CORPORATION AND ITS SUBSIDIARIES (collectively, “Renesas”) DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. Renesas provides evaluation platforms and design proposals to help our customers to develop products. However, factors beyond Renesas' control, including without limitation, component variations, temperature changes and PCB layout, could significantly affect the product performance. It is the user’s responsibility to verify the actual circuit performance.