An IoT device that teaches correct table tennis techniques

Uses HMC5883L_3-Axis_Digital_Compass_IC

Objective

• Invent an IoT (Internet of Things) product

• Teaches person how to play table tennis on his own with guidance

• Swing Analyzer by measuring angles of swing in 3D

Approach

Utilising the systems of a microprocessor, magnetometer and accelerometer, the final product is able to track the angle, direction and accerelation of hand movement. The system autonomously sends the data over a wireless communication to the server, where the analysis is carried out and any successful swings and individual feedback/records are output in realtime, capable of guiding a person how to play table tennis on his own.

Sending of data to MQTT broker

• Mosquito broker setup on a laptop

• Device sends to laptop via MQTT (JSON format) through EEERover network

• Server(cloud) receives JSON packets and processes data and outputs statistics of counts and guidance to improve swings

On device processing/formatting

• Triggered by push button to switch between swing detection and compass

• Utilize accelerometer to set a threshold of detecting swing

• Differentiating different types of swing by determining the angle difference using data from magnetometer

Addition sensors, other I/O, cloud functionality

• Adapted accelerometer onto board for measurement triggering

• Only send data when accelerometer above certain magnitude(swing detected), minimising data sent

• Server acts like a cloud, processing and output can be sent to app/website/other device, etc