Nordic-powered smart skipping rope provides heart rate detection to optimize workouts

Laisi Tech’s F20L and F20PRO skipping ropes employ nRF52840 SoC to measure user’s heart rate, jump count, and jump time

Sports and health technology company Laisi Tech has launched two smart skipping ropes that provide live voice-based workout suggestions based on data from heart rate and gravity sensors. The ‘F20L’ and ‘F20PRO’ use these metrics to ascertain the efficiency of the user’s workout, and provide ‘real time’ audio feedback to suggest increasing or decreasing exercise intensity for fat burning or endurance, for example.

Both the F20L and F20PRO employ Nordic Semiconductor’s nRF52840 SoC, with its 64 MHz, Arm® Cortex® M4 processor with floating point unit (FPU) providing ample computational resource to supervise the skipping rope sensors. The sensor data is relayed to the ‘PaiHealth’ app on the user’s smartphone using the SoC’s Bluetooth® LE wireless connectivity. From the app the user can review their exercise data, access thousands of free tutorials, as well as smart training tips, and challenges and competitions, for example. In the absence of a smartphone, the F20L and F20PRO’s color screen can display a timer, the user’s jump count, heart rate, the current battery level, as well as up to 48 sets of historical data, thanks to the nRF52840 SoC’s generous 1 MB Flash memory allocation.

The ultra-low power consumption was one of the main drawcards when selecting the nRF52840 SoC

Yiqun Zhong, Laisi Tech

Real time feedback

“We wanted to make a smart skipping rope that could provide the user with real-time feedback on heart rate and exercise intensity to help them achieve their fitness goals,” says Yiqun Zhong, Marketing Manager at Laisi Tech. “The two different models each target users with different skill levels. The F20L is ideal for beginner and intermediate users, while the F20PRO includes adjustable weight handles—and can increase fat burning efficiency by up to eight percent—for more advanced users.”

Both devices include a two-way V-shaped card slot design, and can fit various rope sizes. They also offer three modes; free jump, time down, and count down. In the free jump mode the timer will run automatically while the skipping rope records the number of jumps, without any restrictions or limits. The one-minute time down mode challenges the user to complete as many jumps as possible in the allotted time. In count down mode, the user must complete a set number of jumps in the shortest possible time.

One month battery charge life

Using a Li-Po battery, both the F20L and F20PRO can be used for one hour a day for up to one month between charges, and can achieve a standby time of up to 30 days. “Battery life was such an important consideration for us,” says Zhong. “As a result, the ultra-low power consumption was one of the main drawcards when selecting the nRF52840 SoC—along with its powerful MCU.

“In addition, the SDK was very useful when creating our application code. Because we have worked with Nordic for more than three years we are very familiar with the performance and architecture of the SoC. Nordic’s after-sales and technical support have also been very helpful throughout the development process.”