Product description
The MyoWare 2.0 LED Shield is designed to display the magnitude of a target muscle's signal and power the MyoWare 2.0 Muscle Sensor with its built-in battery. The blue 10-segment bar graph shows the magnitude of the measured signal. The more muscle activation measured, the higher up the board LEDs will go! With this shield, you will be provided with a visual representation of the signals provided by the MyoWare 2.0 Muscle Sensor. The LED shield is equipped with snap connectors on the board so you can easily stack it on the top side of the MyoWare 2.0 Muscle Sensor and flip the switch to the ON position to give the sensor all the power it needs to work its myoelectric magic.
More information is available on the website of Sparkfun.