Gravity: Analog EMG Sensor by OYMotion

The Gravity Analog EMG Sensor by OYMotion is an active surface electromyography detection module designed for robotics, human-computer interaction, and biological signal research. Developed in collaboration with DFRobot, it offers students, hobbyists, and developers an accessible way to monitor muscle activity and strength without complex medical setups.

Integrated signal amplification and filtering

The transmitter board amplifies raw sEMG signals within plus or minus 1.5mV by 1000 times. It uses differential inputs and an analog filter circuit to suppress noise and power frequency interference, providing an analog output from 0V to 3.0V around a 1.5V reference.

Reusable metal dry electrodes

Unlike disposable medical patches, the included dry electrode board requires no conductive gel, making it durable and convenient for repeated use. The board measures 22mm by 35mm and attaches using a 50cm cable and a wrist belt.

Microcontroller and Arduino integration

Equipped with a standard Gravity 3-pin interface, the sensor connects seamlessly to Arduino and other development boards. It allows controllers to detect muscle tension and strength for interactive installations, bionics, and robotic control systems.

Sampling and power requirements

The module requires a stable 3.3V to 5.5V DC power supply with at least 20mA current capacity. It captures an effective spectrum range of 20Hz to 500Hz, with recommended digitisation using an ADC with over 8-bit resolution and a minimum 1kHz sampling rate.

Kit contents and application scope

The kit includes the signal transmitter board, dry electrode board, electrode cable, wrist belt, and Gravity analog cable. Please note that this sensor is designed for educational, maker, and control projects, and is not certified for medical diagnosis or treatment.

Video

Downloads & documentation

• Product wiki (DFRobot)