Microcontroller-Based Sentry System

David Penrose’s “Sentry” project comprises an array of passive IR sensors placed throughout a building to track motion. The microcontroller-based system comprises an RF link to a processor along with an Ethernet module to unobtrusively monitor motion and activity levels.

The Sentry system uses commercial IR motion sensors (lower left) together with a customer vibration sensor (lower right) to determine where an individual is within a building. The base unit (top) integrates reports from these sensors to generate alerts to a caregiver.

Photo 1: The Sentry system uses commercial IR motion sensors (lower left) together with a customer vibration sensor (lower right) to determine where an individual is within a building. The base unit (top) integrates reports from these sensors to generate alerts to a caregiver.

Penrose writes:

My Sentry System is designed to assist those folks living alone who desire the peace of mind provided by a caregiver looking after them without the caregiver having to be present. Its implementation was facilitated by the WIZnet WIZ550io Ethernet module, which provides a rich yet simple interface to the Internet. With a simple microprocessor, the system allows the status of a resident to be continuously monitored in a minimally intrusive fashion.

Any abnormal conditions can immediately be alerted to a remote caregiver for action. In this way, a caregiver’s smartphone acts as an alert system by letting them know when a resident’s activity deviates from a normal pattern. The system is designed to be simple to set up yet very flexible in its application so the needs of different residents can be addressed. A resident with minimal needs can be monitored by a set of relaxed rules, while a resident in need of more continuous observation can be assigned a set of strict rules. In all cases, the overarching design approach was to provide a system that augments the caregiver’s capability.

Penrose goes on to describe the system:

The Sentry System integrates motion sensors, a microprocessor, and the WIZ550io Ethernet interface to monitor a resident and report abnormal activity patterns to a remote caregiver (see Photo 1). The relationship of these subsystems is illustrated in Figure 1.

Up to eight sensors transmit activity to a base unit processor, which checks for abnormal behavior of a resident. Alerts to a caregiver are generated and communicated over the Internet.

Figure 1: Up to eight sensors transmit activity to a base unit processor, which checks for abnormal behavior of a resident. Alerts to a caregiver are generated and communicated over the Internet.

The primary sensors are IR motion sensors. These can be augmented by vibration sensors, pressure mats, ultrasonic, and other devices capable of detecting a person’s presence. These sensors are placed at key locations in a resident’s home to monitor movement from room to room or within rooms. The vibration sensors are placed in favorite chairs/couches or in the bed to determine if the furniture is occupied and if there is normal activity. All of these sensors are battery powered and report over an RF link. The RF reports from these devices are received by a base unit which then compares the resident’s location and activity to a set of rules that define normal behavior for different times of day. Any deviation from normal results in an SMS text message or e-mail being sent to the caregiver along with information about how to contact the resident. In most cases, it is expected that the caregiver would respond by phoning the resident to check on them.

The system is designed to be easy to install and operate. The WIZ550io’s Internet interface is used to communicate to a browser allowing the caregiver or resident to configure the system. This configuration consists of identifying sensors and rooms and describing a set of rules for each room for periods in the day. This local interface also allows for a review of all past activity once the system is operational. This history data is valuable for refining the rules to reduce false alarms and ensure security. Since the interface is behind the resident’s firewall, the system is secure from improper modification. The key output from the system is the alert to the caregiver, which relies on the WIZ550io module communicating to a service site such as Exosite. The site generates the alerts sent to the caregiver.

The base unit incorporates the WIZ550io, an 89LPC936 processor, a MCP79401 real-time clock, and a serial EEPROM to process reports received from the 433-MHz receiver.

Photo 2: The base unit incorporates the WIZ550io, an 89LPC936 processor, a MCP79401 real-time clock, and a serial EEPROM to process reports received from the 433-MHz receiver.

The system’s hardware consists of a base unit and multiple sensor/reporting units. The base unit (see Photo 2) comprises a WIZ550io Ethernet interface, an inexpensive microprocessor, an RF receiver, a battery backed-up real-time clock, and a serial EEPROM. All of these pieces are integrated into a small form factor case and powered by a plug-in transformer (see Figure 2).

Figure 2: The microprocessor accomplishes all of its tasks while using only a few of the available port pins.

Figure 2: The microprocessor accomplishes all of its tasks while using only a few of the available port pins.

The remote units can be one of many different sensor/reporting devices depending on the needs of the resident. The basic sensor is the IR motion sensor, which is available from a number of different sources.  I used Bunker Hill Security sensors, which I purchased from Harbor Freight Tools (Item 93068). A sensor plus receiver is very inexpensive. Some cost only $11. The item consists of a sensor/transmitter and a receiver/alarm device. The receiver/alarm device is not used in this project although the RF receiver was lifted from one of these units to provide the receiver for the base unit. These sensor units are powered by 9-V batteries and report on an RF link at 433 MHz with a unique address code.  The code allows multiple sensors to be deployed and recognized by the base unit.

The complete article appears in Circuit Cellar 296 (March 2015).

DIY Network-Ready Polyphonic Music Controller

Hans Peter Portner’s Chimaera project is a touch-less, expressive, network-ready, polyphonic music controller released as open source hardware. It is a mixed analog/digital offspring of the Theremin. An array of analog, linear Hall effect sensors make up a continuous 2-D interaction space. The sensors are excited with Neodymium magnets worn on fingers.

Portner's Chimaera project

Portner’s Chimaera project

The device continuously tracks and interpolates position and vicinity of multiple present magnets along the sensor array to produce corresponding low-latency event signals. Those are encoded as Open Sound Control bundles and transmitted via UDP/TCP to a software synthesizer. The DSP unit is a mixed-signal board and handles sensor read out, event detection and host communication. It is based on an ARM Cortex M4 microcontroller in combination with WIZnet W5500 chip, which takes care of all low-level networking protocols via UDP/TCP.

First Prize — Chimaera: The Poly-Magneto-Phonic Theremin, Hans Peter Portner (Switzerland)

The poly-magneto-phonic Theremin

In his project write-up, Portner explains:

With its touch-less control (no friction), high update rates (2-4 kHz), its quasi-continuous spatial resolution and its low-latency (<1 ms), the Chimaera can react to most subtle motions instantaneously and allows for a highly dynamic and expressive play. Its open source design additionally gives the user all possibilities to further tune hardware and firmware to his or her needs. The Chimaera is network-oriented and configured with and communicated by Open Sound Control, which makes it straight-forward to integrate into any setup.

The hardware of the Chimaera consists of two types of printed circuit boards and an enclosure. Multiple sensor units are daisy-chained to form the sensor array and connected to a single digital signal processing (DSP) unit.

Sensor unit

Sensor unit

A single sensor unit consists of 16 linear hall-effect sensors spaced 5mm apart and routed to a single output through a 16:1 multiplexer which is switched by the DSP unit. Downstream the multiplexer, the analog signal runs through an amplification circuitry.

A modular hardware design consisting of identical sensor units and a single DSP unit embedded in a wooden case allows building devices with array sizes of 16-160 sensors.
A modular hardware design consisting of identical sensor units and a single DSP unit embedded in a wooden case allows building devices with array sizes of 16-160 sensors.

The DSP unit is a mixed-signal board and handles sensor read out, event detection and host communication. It is based on an STM32F303Cx ARM Cortex M4 microcontroller in combination with WIZnet W5500, a hardwired 100Mbit IPv4/PHY chip taking care of all low-level networking protocols via UDP/TCP. The board’s analog part features 10 analog inputs providing connection points for the sensor units, leading to a maximally possible array of 160 sensors. Those analog inputs connect directly to three in parallel running 12bit analog-to-digital converters.

Schematic of the DSP unit (STM32F303Cx part)

Schematic of the DSP unit (STM32F303Cx part)

Networking technology in a zero configuration setup has advantages in respect to long-distance transmission, operating system independence and inherent ability for network performances. We thus use the Open Sound Control (OSC) specification via UDP/TCP as low-level communication layer.

Schematic of the DSP unit (WIZnet W5500 part)

Schematic of the DSP unit (WIZnet W5500 part)

Portner’s project won First Prize in the WIZnet Connect the Magic 2014 Design Challenge. The entire project and its associated files are now available.

WIZnet Design Challenge Winners (Sponsored)

WIZnet’s Connect the Magic 2014 Design Challenge provided electronics enthusiasts with the opportunity to use WIZnet’s WIZ550io Ethernet module in a project for a chance to win a share of $15,000 in prizes. The submission deadline was August 3, 2014, and soon thereafter the judges began scoring the entries. We’re excited to announce that the results are now in and winning projects are live.

First Prize — Chimaera: The Poly-Magneto-Phonic Theremin, Hans Peter Portner (Switzerland)

First Prize — Chimaera: The Poly-Magneto-Phonic Theremin, Hans Peter Portner (Switzerland)

You can study the complete projects (documentation, schematics, photos, code, and more) on the Winners Page. Congratulations to the following winners!

WINNING PROJECTS

  • First Prize — Chimaera: The Poly-Magneto-Phonic Theremin, Hans Peter Portner (Switzerland)
  • Second Prize — LCDTV Server: Streaming Media Using Ethernet/USB Adapter, Lindsay Meek (Australia)
  • Third Prize — WIZ Security Network, Claudiu Chiculita (Romania)
  • Honorable Mention — Sentry, David Penrose (United States)
  • Honorable Mention — Automatic Animal Feeder, Dean Boman (United States)
  • Honorable Mention — WIZpix: Connected pixel controller, Robert Gasiorowski (United States)
  • Honorable Mention — The Instrument of Things, Radko Bankras (The Netherlands)
  • Honorable Mention — Radio Telescope Controller, Clayton Gumbrell (Australia)

    Honorable Mention — WIZpix: Connected pixel controller, Robert Gasiorowski (United States)

    Honorable Mention — WIZpix: Connected pixel controller, Robert Gasiorowski (United States)

WIZNET TECHNOLOGY

WIZnet’s WIZ550io is an excellent module for rapidly developing ’Net-enabled systems. It is an auto-configurable Ethernet controller module that includes the W5500 (TCP/IP-hard-wired chip and PHY embedded), a transformer, and an RJ-45 connector.

The WIZ550io has a unique, embedded real MAC address and auto network configuration capability. When powered up, the WIZ550io initializes itself with the MAC and default IP address and can be pinged from your computer. You don’t need to write MAC and network information such as an IP address, subnet mask, and gateway address.

The W5500 chip is a hardwired TCP/IP embedded Ethernet controller that enables Internet connection for embedded systems using Serial Peripheral Interface (SPI).

IoT Innovation: Show Off Your W5500 Project (Sponsored Post)

The WIZnet Connect the Magic Challenge offers you a variety of opportunities to show off your engineering skills and present your Internet of Things (IoT) designs to the world. It’s your shot to win a share of $15,000 in prizes, gain international recognition as innovator, and more.

Elektor/Circuit Cellar is the challenge administrator for the WIZnet Connect the Magic 2014 Design Challenge

Elektor/Circuit Cellar is the challenge administrator

Don’t delay! The submission deadline is ​August​ 3, 2014. All Entries must be received on or before 12:00 PM EDT on ​August 3​, 201​4​.

To Enter, simply upload your Entry via the Entry Dropbox.

OTHER OPPORTUNITIES
Didn’t finish your project? You can still participate.

If the deadline approaches and your entry is not complete, we still encourage you to submit your project or submit a project after the deadline. While only these on-time files are submitted to the judges, consider that there are many more opportunities for contest success, such as Elektor/Circuit Cellar’s “Distinctive Excellence” awards.

While Elektor/Circuit Cellar must follow the Sponsor’s rules about submission and judging when it comes to the contest’s official prizes, Elektor/Circuit Cellar is able to include its own award program that takes into account design skills that may otherwise go unrecognized.

By submitting even an unfinished project by the deadline for official judging, you qualify for a Distinctive Excellence review. If there is merit and the project warrants further consideration, those projects that may be offered a Distinctive Excellence award may be updated by the entrant after the contest deadline.

Historically, there have been some really fascinating Distinctive Excellence projects for previous Elektor/Circuit Cellar design contests. Those who win this designation see their projects posted online similar to the official winners and enjoy much of the same exposure. Many are offered separate print magazine publishing deals through Elektor/Circuit Cellar. The benefits of having Elektor/Circuit Cellar recognize and publicize your work in a high profile campaign like this should not be underestimated.\

Plus … Due to Elektor and Circuit Cellar’s international reach, you’ll get even more exposure than ever before! Imagine getting a Distinctive Excellence award—or getting your article published—and being recognized by readers throughout the world! That could lead any number of positive outcomes. Job opportunities? Design deals? The sky is the limit!

THE CHALLENGE

You are challenged to design and build an innovative project that uses least one WIZnet WIZ550io Ethernet controller module or W5500 chip. You can use any other MCU and/or module along with the WIZ550io Ethernet module.

W5500

W5500

WIZnet PARTS

Your project must use at least one WIZnet WIZ550io Ethernet controller module or WIZnet W5500 chip. You can use any other MCU and other module along with the WIZ550io Ethernet module or W5500 chip. Visit the Eligible Parts page for more information.

WIZnet's WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

WIZnet’s WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

HOW TO PARTICIPATE

Participation is simple. First, read the Rules. Second, build and thoroughly document a project featuring a WIZnet WIZ550io Ethernet Controller module or W5500 chip. Next, Register for the Challenge and obtain a Project Registration Number. Lastly, Submit a complete project Entry.

JUDGING 

The goal of the Challenge is to showcase the functionality of the WIZnet WIZ550io module. All Challenge entries will be judged by a panel of judges on the following: technical merit 30%, originality 30%, usefulness 20%, cost-effectiveness 10%, and design optimization 10%. It would be smart to highlight these achievements in your documentation. Call attention to your project’s special features.

WIZnet Challenge Entry Tips (Sponsored Post)

The WIZnet Connect the Magic Challenge deadline is ​August​ 3, 2014. Let’s go over the challenge and cover some tips for entering.WIZnetconnect_logo_horweb_550x

What is the Challenge?

You are challenged to design and build an innovative project that uses least one WIZnet WIZ550io Ethernet controller module or W5500 chip. You can use any other MCU and/or module along with the WIZ550io Ethernet module.

What devices must I use with my project?
Your project must use at least one WIZnet WIZ550io Ethernet controller module or WIZnet W5500 chip. You can use any other MCU and other module along with the WIZ550io Ethernet module or W5500 chip. Visit the Eligible Parts page for more information.

WIZnet's WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

WIZnet’s WIZ550io auto configurable Ethernet controller module includes a W5500, transformer, & RJ-45.

How do I participate?

Participation is simple. First, read the Rules. Second, build and thoroughly document a project featuring a WIZnet WIZ550io Ethernet Controller module or W5500 chip. Next, Register for the Challenge and obtain a Project Registration Number. Lastly, Submit a complete project Entry.

​​May I submit multiple entries?
Yes. You may submit as many entries as you want. Each Entry must have its own Project Registration Number. Complete a Project Registration Form for each Entry you intend to submit.
What types of projects win design contests?
The goal of the Challenge is to showcase the functionality of the WIZnet WIZ550io module. All Challenge entries will be judged by a panel of judges on the following: technical merit 30%, originality 30%, usefulness 20%, cost-effectiveness 10%, and design optimization 10%. It would be smart to highlight these achievements in your documentation. Call attention to your project’s special features.