WHOOP: Unlocking Human Performance with MAX32652

WHOOP’s mission is to unlock human performance. Based in Boston, Massachusetts, the company is behind the WHOOP Strap 3.0, a wearable with an accompanying app that provides users with insights into fitness parameters such as recovery, strain, and sleep. Armed with this data, members can make better lifestyle choices with real-time feedback on their bodies.

The second generation WHOOP Strap streamed acquired data via the Bluetooth® protocol to the user’s cellphone. The phone would then send the data to the cloud and WHOOP’s cloud service would run an algorithm on the acquired data, displaying the information back to the user on a web portal. The strap’s battery would last a maximum of three days on a charge. For its next-generation product, the company wanted to offer more.

Challenges

  • Ability to process acquired user data locally
  • Extend battery life without changing the device’s form factor

Solutions

Benefits

  • Extended battery life to 5 days versus 3 days of preceding device, without changing device form factor
  • Local user data processing at low levels of power draw

The WHOOP Strap 3.0 with accompanying app provides wearers with insights into fitness parameters such as recovery, strain, and sleep.  The WHOOP Strap 3.0 with accompanying app provides wearers with insights into fitness parameters such as recovery, strain, and sleep.

Challenges

To differentiate WHOOP Strap 3.0 from its predecessor, WHOOP wanted the new strap to be able to process the acquired user data locally. The company also wanted to extend the wearable’s battery life to five days, while maintaining the same form factor as the 2.0 device. To accomplish these goals, the company needed a way to infuse its new strap with high levels of processing power at ultra-low levels of power draw.

Solution and Benefits

WHOOP has integrated several Maxim ICs into the WHOOP Strap 3.0. The MAX32652 ultra-low-power Arm® Cortex®-M4 with floating-point unit-based microcontroller was made for high-performance, battery-powered applications. With 3MB flash, 1MB SRAM, and multiple memory-expansion interfaces, the MAX32652 provides the onboard memory and processing power at low power consumption WHOOP needed. The WHOOP Strap 3.0 can run algorithms locally to process the acquired user data and its battery lifetime is at five days versus the three days of the preceding device. Its form factor is the same as the 2.0 version.

Running the algorithm on the strap itself reduces the power draw because the amount of Bluetooth radio traffic that must move between the strap and the user’s cellphone has been reduced. Other Maxim ICs in the design are the MAX14745 power management IC with ultra-low IQ voltage regulators and battery charger and the MAX17223 nanoPower synchronous boost converter with True Shutdown™. These devices contribute to the new strap’s efficient, space-saving power architecture.

Maxim field application engineers supported the WHOOP team as the engineers developed firmware for the microcontroller to enable new capabilities of the strap.