C4001 24GHz mmWave Presence Sensor 25m UART

The C4001 from DFRobot is a 24 GHz radar sensor with FMCW modulation that detects people even when they sit, lie or sleep still. It detects presence up to 16 m and motion up to 25 m, and also measures distance and speed. Data is sent via UART, and the OUT pin switches when something is detected. The sensor runs on 3.3 V and 5 V, for example on Arduino or ESP32.

Variant with Gravity connector, I2C and UART, range 12 m: Gravity C4001 24GHz mmWave Presence Sensor 12m I2C UART

Recommended Accessories:

• Dupont Jumper Cable Set 20cm 60 Pieces.

Features:

• Presence up to 16 m, motion up to 25 m; according to DFRobot these are different tasks, not one common maximum
• Distance 1.2 to 25 m and speed 0.1 to 10 m/s
• Also detects small movements such as breathing, unlike a PIR sensor
• Beam angle 100° × 40°
• UART at 9600 baud, OUT pin as switching signal
• Mounting on the ceiling, on the wall or tilted; the mounting method affects the detection area (DFRobot)
• According to DFRobot unaffected by temperature, humidity, dust, light and noise
• DFRobot_C4001 library for Arduino; DFRobot also names ESPHome and Home Assistant

Application Examples:

• Switching light and ventilation in the bathroom or office based on presence
• Detecting occupancy of long corridors and large rooms
• Presence signal for alarm and monitoring projects
• Measuring distance and speed of people or objects

Documentation:

• Wiki DFRobot SEN0609
• Arduino example motion detection (DFRobot Wiki)
• Arduino example distance and speed (DFRobot Wiki)
• Library DFRobot_C4001 (GitHub)
• Tutorial C4001 with Arduino and ESP32 (Makerguides)
• Datasheet (PDF)
• Dimension drawing (PDF)

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: SEN0609
• Operating voltage: 3.3 V or 5 V
• Frequency: 24 GHz
• Modulation: FMCW
• Motion: up to 25 m
• Presence: up to 16 m
• Distance measurement: 1.2 to 25 m
• Speed: 0.1 to 10 m/s
• Beam angle: 100° × 40°
• Interface: UART (9600 baud), OUT switching output
• Pins: VIN, GND, RX, TX, OUT
• Operating temperature: -40 to 85 °C
• Dimensions: 26 × 30 × 3.6 mm
• Weight: 4.3 g

Scope of Delivery:

• 1× C4001 24 GHz radar sensor 25 m
• 1× pin header 5-pin, loose