Wireless technology is worming its way into just about everything these days. One wouldn't think of a soccer ball as a vehicle for electronics, but such is the case with Adidas's miCoach Smart Ball. Used in 2022 FIFA World Cup matches and by all major soccer leagues, the ball contains some rather sophisticated circuitry in the form of a 6-axis, MEMS-based motion sensor from TDK InvenSense.
The Adidas balls are outfitted with TDK's ICM-42686-P device, which comprises a 3-axis gyroscope and a 3-axis accelerometer on the same silicon die. As can be seen in the accompanying video with Rob Dick, an applications engineer at TDK InvenSense, the device is suspended at the center of the ball's interior and tracks the ball's movement.
Motion sensors within soccer balls serve at least two purposes: Their data can determine, to a very high degree of accuracy, whether a goal has (or has not) been scored. They're also valuable in training and monitoring performance of individual athletes.
Data from the sensor is transmitted with ultra-wideband (UWB), which uses pulsed packet data transmissions spread over a bandwidth of over 500 MHz. This enables extremely high transfer rates over a range of about 100 meters. Using UWB in this application provides high data throughput without interfering with conventional narrowband and carrier-wave transmissions, even if they share the same frequency band.
The ICM-42686-P device is effectively identical to the company's ICM-42688-P. The difference is that the former (the datasheet for which isn't public) offers extended range (±32 g, ±4000 dps vs. ±16 g, ±2000 dps) compared with the ICM-42688-P).