Jan 21, 2020Several technology companies are leveraging radio frequency identification not only to transmit data, but also to power their devices, thereby ensuring consistent performance from sensor-using systems designed to make it easier to find and manage products and assets. Smart sports ball company SportCor has sold its electronics to cricket ball manufacturer Kookaburra and is marketing the product for balls used in a variety of other sports around the world.
The SportCor system employs sensors to capture data regarding a ball's location and performance, with Bluetooth Low Energy (BLE) to transmit data back to a smartphone or gateway device. RF plays its own role in the system by powering the device wirelessly, employing the same 2.4 GHz antenna that transmits the Bluetooth signal. The RF-based powering system is provided by Powercast. Thus far, Powercast is the first company to deploy solutions and products that enable RF wireless power, says John Macho, the firm's product manager.
Throughout the past three years, SportCor has developed an embeddable smart electronics core that consists of sensors, as well as the related electronics to transmit that sensor data to a BLE beacon device in a gateway or phone. Kookaburra is building the electronics into its smart cricket balls to provide cricket players and coaches with intelligence, such as speed, distance, force, position and spin.
SportCor was founded to create a technology-based solution to find missing golf balls for golfers, says Ben Tattersfield, SportCor's founder and head of innovation. When Tattersfield plays golf, he says, he often loses balls. "I wanted to create a golf ball I could track with my phone," he states. He built a prototype of a ball that could sustain the blows of a club swing and be located via GPS and BLE transmissions. The golf industry didn't show interest in the product, however, since lost golf balls drive sales for companies that make replacements. But companies in other markets were more intrigued, and SportCor began working with Kookaburra and other ball manufacturers. "We like to partner up with existing sport equipment brands."
Kookaburra's field hockey and cricket balls are used worldwide. The company recently released its latest ball with intelligence, which can track data about how it is being played for training or gameplay purposes. The SportCor unit built inside the ball includes accelerometers and other sensors so that it can collect information regarding how it is being played—the speed at which it is hit, how much it spins and how fast it moves. The ball then transmits this data via Bluetooth to a base station or phone, which forwards the information to the cloud.
To capture and forward data, the Smart Ball requires a standard, rechargeable lithium battery. However, Tattersfield says, "We can't have a USB port on the side of the ball," so the company looked into wireless charging. One challenge involves getting the charging transmission into the center of a ball, using the same antenna utilized for transmission and a small Powercast RF receiver. In this way, the system won't impact the ball's size or movement.
Thus, the core needed to receive a recharging transmission at 2.4 GHz, which enables a minimally sized antenna in comparison to other frequencies. "Another challenge was to keep the size as small as possible," Macho says. Powercast provided engineering-as-a-service to modify the system to enable the 2.4 GHz transmission, while the receiver converts the power to DC in order to recharge the battery. Powercast began working with SportCor in the fall of 2018, and a prototype was developed last year.
These days, Tattersfield says, the product is up to version 4. The electronics weigh approximately 7 grams (0.24 ounce), and with a frame to sustain blows, that brings the weight to 20 grams (0.7 ounce). Inside the cricket ball, a dense rubber pill has been replaced with the core. The end result is that the Smart Ball is the same weight as a standard ball. It was designed to provide the same sensory experience as the standard ball while in play, the company explains, including the sound it makes when the ball impacts with a cricket bat. SportCor's engineers worked with sports scientists and professional cricket players to help accomplish the right sound and feel.
Users must download an app and purchase the smart ball with the Powercast-branded charger. "From the user's point of view," Tattersfield explains, "all they have to do is put the ball on a dock." A lid is placed over the docking station, after which recharging takes place within about eight hours. When in use, the ball typically can send a Bluetooth signal to a BLE-enabled phone at a distance of about 75 meters (246 feet). SportCor also offers a BLE gateway that can be mounted at ball parks or other sites that receive 2.4 GHz transmissions at up to 150 meters (492 feet).
The company is currently developing a recycling process for the electronics since they tend to outlast the ball's lifespan, Tattersfield reports. In addition, Powercast and SportCor are planning a bulk charger that can charge dozens of balls simultaneously, and Powercast is providing its RFID charging solution for other use cases, Macho says, such as electronic baggage tags for British Airways.
The airlines' reusable digital tags, provided by ViewTag, are updated with passenger flight information, and are designed to display data about a specific bag's destination. It can be updated via an RFID transmission as many as 3,000 times. Like the SportCor ball, the baggage tag, branded by British Airways as TAG, requires wireless recharging. The TAG remains in a dormant stage unless it is within range of an airport RFID reader. At that time, the reader wakes it up and can write new information to the screen. After the screen has been rewritten, the TAG returns to sleep mode and the battery is no longer needed for power.
The baggage label has an embedded Powercast Powerharvester receiver chip and a dedicated antenna to receive transmissions from a phone's Bluetooth function. It can power up and respond to an RFID reader at an airport, as well as pair with a passenger's smartphone via Bluetooth. For tags that will be attached to luggage over the course of many flights, Macho says, "The important thing is for it to be durable and fully sealed so it can be OK mechanically when out in the environment."
Another market for the Powercast charging system is Internet of Things (IoT) devices that are battery-free, such as lighted packaging. Some solutions offer a passive system for LED lighting that that could be built into smart credentials or packaging. For example, PPG Teslin makes a substrate with conductive inks. Powercast's power-harvesting ICs can be mounted on the substrate and leverage the conductive ink as an antenna to receive a transmission from an RFID interrogation. That power could then light up an LED—for instance, illuminating a product on store shelves to capture shoppers' attention. This application is still in the development stage.