Wireless sports timing solution provides accurate high-speed data for enhanced participant and spectator experience

Mobii Systems

Nordic’s nRF52840 SoC helps Mobii Systems’ Active Transponder and Active Pod wirelessly connect and store data for race timing solution

Nordic Semiconductor today announces that Mobii Systems, a Cape Town, South Africa-based sports technology company, has selected Nordic’s nRF52840 advanced multiprotocol System-on-Chip (SoC) to provide processing power, data storage, low power 2.4GHz communication, and over-the-air device firmware update (OTA-DFU) capability for the ‘Active Transponder’ and ‘Active Pod’ devices within its ‘Mobii Timing’ ecosystem of sports timing solutions. 

Mobii Timing provides a full suite of hardware, software, and a Cloud-based platform enabling sports event organizers and timing providers to accurately read, record, and display individual timing splits throughout races – enhancing sports events for participants and spectators alike. Working together, the Active Transponder and Active Pod are intended for use in medium-sized participation events such as triathlon, canoeing, cycling, and motorsports. The platform works even when participants are moving at speeds in excess of 300km/h.

The Active Transponder uses a solar cell and energy harvester to charge its small Li-Poly battery – a world first in the timing industry, according to company. 
Nordic is a brand that we have learnt to trust for reliability, performance, and availability
Michael Thacker, Mobii Systems
In operation, the Active Transponder integrating Nordic’s nRF52840 SoC is attached to the arm or leg of a race participant, or on to equipment such as a bicycle or boat. Active Pods placed at various fixed locations along the route of a race (including the start and/or finish line) can then wirelessly read and record the high-speed timing data triggered by the Active Transponders as each participant passes each reader. The Active Pod employs two Nordic nRF52840 SoCs to synchronize and interrogate the Active Transponders passing close by. One SoC behaves as a primary transmitter to ‘wake up’ and synchronize the Active Transponders; the other SoC receives the data from the Active Transponder. The nRF52840 SoC’s generous 1MB Flash memory and 256kB RAM provide the Active Pod with sufficient memory allocation for recording and storing the mass timing data required in organized events with potentially thousands of participants. 
The wireless connectivity between the transponder and the pod/reader is achieved using a low latency, low power consumption 2.4GHz proprietary protocol using Nordic’s proprietary Enhanced ShockBurst (ESB) technology. The transponder and the pod/reader are able to communicate with each other over a range of up to 100 meters, according to Mobii Systems. Nordic’s nRF52840 SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU), with a 2.4GHz multiprotocol radio (supporting 2.4GHz RF protocol software in addition to Bluetooth® 5.2, ANT™, Thread, Zigbee, and IEEE 802.15.4). The Nordic SoC’s Bluetooth LE wireless connectivity supports the over-the-air device firmware update (OTA-DFU) functionality enabling secure software updates of the Active Transponder. 
Mobii Timing software can be used on a laptop or PC to retrieve data locally from the pods/readers for live consumption, monitoring, and scrutiny at any event. The solution also features a Cloud-based platform for race configuration, participant registration, and digital display of results. In remote operation mode, the pods/readers can upload data directly to the Cloud for synchronization using any of the built-in networking capabilities, allowing the information to be sent from start points and/or checkpoints to a leaderboard at the finish line for live consumption.
Nordic’s nRF52840 is Nordic’s most advanced ultra low power nRF52 Series SoC. The SoC supports complex Bluetooth LE and other low-power wireless applications that were previously not possible with a single-chip solution. The nRF52840 is Bluetooth 5.2-, Thread 1.1-, and Zigbee PRO (R21) and Green Power proxy specification-certified and its Dynamic Multiprotocol feature uniquely supports concurrent wireless connectivity of the protocols. A new radio architecture with on-chip PA provides features -95-dBm RX sensitivity (at 1Mbps Bluetooth LE), a maximum output power of 8dBm, and a total link budget of 103dBm. Designed to address the inherent security challenges that are faced in IoT, the nRF52840 SoC incorporates the Arm CryptoCell™-310 cryptographic accelerator, offering best-in-class security. The SoC is supplied with Nordic’s S140 SoftDevice, a Bluetooth 5.2-certified software protocol stack.
“The key features behind our decision to select Nordic’s nRF52840 SoC for our Active Transponder device include the chip’s multiprotocol radio, radio and NFC combination, compact size, power consumption, large Flash memory for data storage, Arm CryptoCell security capability, and VDDH battery voltage sampling without the need for additional components,” says Michael Thacker, Lead Hardware Engineer at Mobii Systems. 
“Having the flexible and well-structured Nordic SDK [software development kit] helped us develop our application code in minimal time. 
“Nordic is a brand that we have learnt to trust for reliability, performance, and availability. A key factor is the ability to design-in Nordic’s products with relative ease due to the high quality of technical information and reference designs.”