Cypress & Inventek Systems – Inventek IoT solutions for commercial LED lighting, powered by Cypress WICED connectivity and PSoC MCU technology

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By Greg Phillips, CTO Cloud Architecture at Inventek Systems, Inc.

For many years, the commercial lighting space was dominated by fluorescent tube lighting. While these provided significant savings over the use of incandescent lighting, they suffered from serious performance, maintenance, and use issues. These included short lifespan, wide colour temperature variation, random flickering and hum, and an inability to effectively dim to save power. In addition, frequently turning the fluorescent lights on and off based on occupancy significantly decreased their lifespan, and increased power use during startup, which often cancelled out the power saved when the fixture was off.

The development of commercial LED lighting has prompted a complete rethinking of how commercial lighting is approached. This has included the addition of smart control systems as a key element of total energy management. These LED fixture controllers, also referred to as LED controllers and luminaires, are now often networked devices. These LED lighting fixtures are the cornerstone of IoT lighting.

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Fig. 1: Inventek iMatrix lighting network architecture

New designs of LED lighting fixtures have many software elements that can provide additional levels of efficiency. This increased efficiency enables power savings of up to 90% over traditional fluorescent lighting fixtures.

Several standards have emerged to ensure that energy savings will be realised when upgrading to more efficient lighting fixtures. The ‘Title 24’ standard introduced in California, in the US, is one specification with which these fixtures must comply in order to pass code compliance.

The elements used to create a leading-edge lighting solution will be discussed below.

Inventek IoT lighting solution system architecture
The Inventek IoT lighting solution involves many elements that work together to provide a complete lighting platform for a commercial building. Key to the system is the iMatrix IoT platform. The Inventek IoT lighting solution consists of the following items:

1. Fixture controller and power management
a. Cypress WICED® Wi-Fi® module for fixture control and communications
b. Cypress PSoC® 4 MCU for special sensor processing used with occupancy detection
2. iMatrix WICED client to provide cloud connectivity for controls and sensors
3. iMatrix mobile applications for Android and iOS used for provisioning and fixture controls
4. iMatrix cloud application for site design, floor plan layouts and fixture placement
5. iMatrix cloud application to monitor and manage deployed fixtures and other sensor elements

Fixture controller and power management
The fixture controller and power management system consist of three primary modules.
1. The Inventek IoT control module incorporating an Inventek WICED Wi-Fi module powered by Cypress, and a Cypress PSoC MCU controller
2. The sensors module
3. The power module incorporating relay controls, power measurement and dimming controls (in and out)

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Fig. 2: Inventek Systems’ Wi-Fi module

The Inventek WICED Wi-Fi module is the key element in the fixture controller. This module is powered by Cypress dual-band Wi-Fi® and Bluetooth® radio subsystems with fully certified integrated antennas. The embedded processor controls all aspects of the fixture’s operation and monitors data such as: Dim level of LED driver, daylight harvesting, temperature, humidity, over-the-air updates, and more.

The Cypress PSoC 4 MCU combines an Arm® Cortex® M0+ with programmable analogue blocks. In the Inventek IoT lighting solution, PSoC 4 MCUs can be used to do the heavy lifting of analyzing the activity from a Passive Infra-Red (PIR) detector and the analysis of audio monitors. This two-factor system is used to determine occupancy and vacancy. The PIR operates well to detect occupancy, but many PIR-only systems falsely detect vacancy conditions while the occupant is still present. Using an audio monitor helps authenticate room occupancy by listening for sound indications of presence such as the click of a mouse or typing.

The Inventek iMatrix IoT cloud platform lighting system components
Inventek iMatrix WICED client

The Inventek iMatrix WICED client runs on the WICED module and is the primary software used to collect sensor data and relay it to the iMatrix cloud system for real-time as well as time series data storage. By constantly monitoring the various sensors of the fixture controller, triggers can be used to notify when error or failed conditions are detected. The sampling rates and trigger levels are defined in the product design during the initial definition of the product. These levels can be updated for one or all of the fixtures using iMatrix cloud services. The iMatrix WICED client provides a secure encrypted TLS/TCP connection to the iMatrix cloud system.

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Fig. 3: PSoC® 4 MCU functional block diagram

The Inventek iMatrix light fixture software
The light fixture controller is an autonomous system with complex software requirements. It performs many tasks that simultaneously monitor for changes in the environment to control its operation. The Inventek iMatrix cloud platform enables all this functionality seamlessly via robust, intelligent control and monitoring management throughout the entire life cycle for each fixture controller, from the manufacturing of each specific controller and throughout the entire life cycle of installation.

For example, during the manufacturing process, each specific model type of the fixture controller is programmed into the configuration system of the Inventek module for each specific fixture. The fixture software knows the appropriate power use expected based on the dim level of the fixture controller. If this power consumption falls below what is expected at a certain dim level then the likely issue is a failed driver or LED board. Maintenance staff can be alerted and quickly service the unit.

iMatrix cloud and mobile elements of the system
The full system includes the iMatrix cloud application, called Apollo, and a matching Apollo mobile application used for control and provisioning.

Using the Apollo iMatrix cloud application, the user initially creates a floor plan of their building and places the fixtures and other items (switches and other BLE sensors). Figure 4 illustrates a typical installation showing the placement of fixtures on a floor plan.

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Fig. 4: The Inventik iMatrix Apollo Lighting API showing fixture controller placement prior to provisioning

The Inventek iMatrix Apollo Mobile Application Pro (iAMAPRO), is used to provision the fixtures in the field. Fixtures are grouped using
a hierarchical structure based on Sites->Buildings->Floors->Rooms- >Groups. During the provisioning cycle, the fixtures are assigned to their associated groups. This is then used to allow the iAMAPRO mobile application to control the operation and setting of the fixtures either individually or by group, as shown in Figure 5.

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Fig. 5: Example of the iMatrix iAMAPRO mobile application controlling three different groups of controller fixtures

Conclusion
Inventek System’s broad portfolio of pin compatible, fully certified Wi-Fi and Wi-Fi + BT/BLE embedded Serial Wi-Fi (eS-Wi-Fi) modules, the eS-Wi-Fi connectivity firmware, Inventek Wireless Interoperability Network (IWIN), the Inventek iMatrix Cloud Platform, combined with Cypress’ industry-leading Wi-Fi and Bluetooth technologies, the WICED software development kit, and mixed-signal configurable PSoC MCUs, has resulted in one of the most highly integrated and complete Lighting solutions available. Using either the WICED development environment or the simplified IWIN AT-based software, Inventek delivers a highly robust, intelligent and scalable lighting architecture that accelerates time to market while enabling maximum energy conservation and efficiency. The designs discussed here, as well as many other IoT applications, are available for licensing from Inventek Systems.