The LEGO Metal Detector—I2C Sensor with EV3 Analog Interface
Grady J. Koch · Apress eBooks · 2020
This chapter examines analog output from the Arduino to be read by the EV3 Intelligent Brick. An example application will be presented of building a metal detector, based on the Grove Inductive Sensor, shown in Figure 5-1. This sensor detects the presence of metal by creating a magnetic field. When a metal is within this magnetic field, an electrical current is induced in the metal, changing the magnetic field created by the sensor. This change in magnetic field is quantified by the Grove Inductive Sensor to give an indication of a nearby presence of a metal. The control of the Grove Inductive Sensor is by an Arduino sketch, which also creates a pulse-width modulated output related to the sensor’s measurement. This pulse-width modulated signal is converted to an analog signal by a low-pass filter, thereby creating an analog signal that can be read by the EV3 Intelligent Brick.