Gravity: Digital Microwave Sensor (Motion Detection)

The microwave sensor applies the Doppler effect to detect moving objects using microwaves. This differs from the method used by a regular infrared (IR) sensor as microwave is sensitive to a variety of objects that are microwave-reflective, and its sensor readings are not affected by the ambient temperature.

This type of microwave sensor is widely used in industrial, transportation and civil applications such as measuring vehicle speed, liquid levels, automatic door motion detection, automatic washing, production line material detection and car reversing sensors etc.
2 Magical Sensors from DFRobot

The microwave detection method has the following advantages compared to other methods:

1. Non-contact detection
2. Readings not affected by temperature, humidity, noise, air, dust or light - suitable for harsh environments
3. Strong resistance to radio frequency interference
4. Low output, unharmful to human
5. Wide detection range and high velocity
6. Supports non-living object detection

Project 1. How to make a Smart Rock-Paper-Scissors Game Robot

When finishing reading this tutorial, you will find those very simple devices, principles and technologies can help you build very interesting equipment.

Hardware list:

DFRduino Uno R3 x 1

Gravity IO expansion shield for Arduino x 1

Tower Pro MG90S servo x 3

Ultrasonic wave sensor x 1

The microwave sensor can be useful together with other sensors to enhance its measurement accuracy. For example, Microwave sensor could decrease the pseudo fault report rate of human motion detection. And it does a good job in safety & security work.

• Working Voltage: 5V + 0.25V
• Working Current (CW): 60mA max., 37mA typical
• Interface: Gravity 3-Pin interface（Digital）
• Size: 48.5x63mm
• Emission parameters:
  • Detection Distance: 2-16M continuously adjustable
  • Emission Frequency: 10.525 GHz
  • Precision Frequency Setting: 3MHz
  • Output Power (minimum): 13dBm EIRP
  • Harmonic Emission: < -10dBm
  • Average Current (5%DC): 2mA typ.
  • Pulse Width (Min.): 5uSec
  • Load Cycle (Min.): 1%
• Reception Parameters:
  • Sensitivity:(10dB S/N ratio) 3Hz to 80Hz
  • Bandwidth: -86dBm
  • 3Hz to 80Hz Bandwidth Clutter: 10uV
  • Antenna Gain: 8dBi
  • Vertical 3dB Beam Width: 36 degrees
  • Level 3dB Beam Width: 72 degrees

• Wiki (digital microwave sensor)
• Related Documents

• Microwave Sensor x1
• Digital Sensor Cable x1